AT9900102 VViRECHAMBER
|lnstitute for High Energy Physics of the Austrian Academy of Sciences February 23-27,1998 30-29 PATRONAGE
The Federal Minister of Science and Transport
The President of the Austrian Academy of Sciences
The Rector of the University of Technology, Vienna
The Rector of the University of Vienna
The European Physical Society
OPENING
The President of the Austrian Council of Rectors P. Skalicky
INTERNATIONAL SCIENTIFIC ADVISORY COMMITTEE
J.E. Augustin, A. Breskin, G. Charpak, S. Denisov, G. Feofiiov, G. Fliigge, H.J. Hilke, S. Iwata, A. Menzione, J. Vavra
ORGANIZING COMMITTEE
W. Bartl, M. Krammer, G. Neuhofer, M. Regler, A. Taurok U. Kwapil (Secretary)
Institute for High Energy Physics of the Austrian Academy of Sciences
SPONSORS
Bundesministerium fiir Wissenschaft und Verkehr The European Commission KongreBbiiro des Wiener Tourismusverbandes Technische Universitat Wien COMMERCIAL SPONSORS
AUSTRIAN AIRLINES Bank Austria AG Cambridge University Press, Cambridge - United Kingdom Creditanstalt AG HAMAMATSU Photonics GmbH, Herrsching - Germany HECUS M. BRAUN GmbH, Graz - Austria Dr. B. STRUCK, Tangstedt (Hamburg) - Germany WIENER, Plein & Baus GmbH, C.A.E.N. S.p.A., Burscheid - Germany TABLE OF CONTENTS
PROGRAMME OVERVIEW (opening, talks, poster sessions, lunch and coffee breaks, social events)
INFORMATION V (accommodation, booking office, lunch, mail, money exchange)
PROCEEDINGS VII (information for authors)
RECEPTION Vm
(offered by the Mayor of Vienna)
CONCERT K
CONFERENCE DINNER "HEURIGER" X (typical Austrian wine-tasting evening) ABSTRACTS
Short talks 1
Poster session A 53
Poster session B 77
LIST OF AUTHORS 101
LIST OF PARTICIPANTS 111
TECHNICAL CONTRIBUTIONS 116 PROGRAMME OVERVIEW
MONDAY, 23 February
14.15 h OPENING
Rector Magnificus P. Skalicky
SESSION 1 Chairman: G. Flttgge
14.30 h F. Sauli: Gaseous Detectors: Recent Developments and Future Perspectives
15.20 h H.J. Besch: Radiation Detectors in Biological and Medical Applications
16.20 h COFFEE
17.00 h Short Talks (Applications in Medicine, Biology and Space Science) 19.00 h COCKTAIL (The cocktail will be offered at the conference place)
COCKTAIL
You will be entertained by the
"New Crazy Blue Danube Steam Boat Stompers" TUESDAY, 24 February
SESSION 2 Chairman: G. Viertel
9.00 h D. Schinzel: High Resolution Electro-Magnetic Calorimetry with Noble Liquids
9.50 h Short talks (Calorimetry, Drift Chambers)
10.40 h INDUSTRIAL EXHIBITION and COFFEE
11.30 h Short talks (Drift Chambers)
12.45 h LUNCH
SESSION 3 Chairman: A. Breskin
14.00 h B. Schmidt: Microstrip Gas Chambers : Recent Developments,
Radiation Damage and Long Term Behaviour
14.50 h Short talks (MSGC)
15.40 h POSTER SESSION A and COFFEE
16.30 h Short talks (MSGC, GEM)
18.35 h END 20.00 h RECEPTION (see page VIII)
WEDNESDAY, 25 February
SESSION 4 Chairman: D. Schinzel
9.00 h I. Giomataris: Micromegas
9.50 h Short talks (Micromegas, Microdot)
10.40 h INDUSTRIAL EXHIBITION and COFFEE
11.30 h Short talks (Simulation, GEM, Gas)
12.45 h END
19.30 h CONCERT (see page IX)
n THURSDAY, 26 February
SESSION 5 Chairman: M. Krammer 9.00 h W. Trischuk: Semiconductor Trackers Physics Detectors
9.50 h Short talks (Silicon Detectors)
10.40 h POSTER SESSION B and COFFEE
11.30h Short talks (Silicon and Imaging Detectors)
12.45 h LUNCH
SESSION 6 Chairman: M. Caria
14.00 h P. Weilhammer: Frontend Electronics and Issues
14.50 h Short talks (Trigger, RPC)
15.45 h POSTER SESSION A (cont.) and COFFEE
16.30 h Short talks (RPC, TPC)
18.35 h END
FRIDAY, 27 February
SESSION 7 Chairman: F. Fabbri
9.00 h G. Mitselmakher: Muon Detection at Hadron Colliders
9.50 h Short talks (Muon Chambers)
10.40 h POSTER SESSION B (cont.) and COFFEE
11.30h Short talks (Muon Chambers and Straws)
12.45 h LUNCH
III SESSION 8 Chairman: R. Veenhof
14.00 h H. Bischof: Recent Developments in Pad Applications in High Energy Physics
14.50 h Short talks (Photo Cathodes, RICH)
15.40 h COFFEE
16.30 h Short talks (Fibers, Aerogel, TRD)
17.45 h M. Turala: Summary talk
18.30 h END
19.30 h WINE-TASTING DINNER (see page X)
IV INFORMATION
CONFERENCE PLACE: Technische Universitat Wien Freihaus Building ("red area"), 1st floor WiednerHauptstra6e8-10, 1040 Wien
POSTER EXHIBITION: Please contact the Conference Secretariat
TRAVEL AGENCY An agent of the Congress Department of the Austrian Travel Agency AUSTROPA will be at the conference desk (see also useful telephone numbers): Sunday, February 22: from 6.00 p.m. until 8.00 p.m. Monday, February 23: from 9.30 a.m. until 6.00 p.m. Tuesday, February 24: from 8.30 a.m. until 6.00 p.m. Wednesday until Friday: in the morning
(Accommodation, sight-seeing, travelling, booking for theatre, concert and opera)
AUSTRIAN AIRLINES - the "Official Carrier" of the conference
BANK SERVICE Monday from 9.30 a.m. until 2.00 p.m. at the conference place,.otherwise Creditanstalt AG Rilkeplatz 8, 1040 Wien (close to the conference building; for opening hours please contact the Secretariat). MAIL Any incoming mail for conference participants will be deposited at the Secretariat and announced on the board beside the conference desk.
LUNCH The self-service canteen (1st floor) and the Schrodinger restaurant (ground floor) will be open. Other restaurants are situated close to the conference building.
PUBLIC TRANSPORTATION IN VIENNA: - One way tickets for any journey in one direction (including transfers) by tram, bus or underground can be obtained from almost any "TABAK-TRAFIK" at ATS 17.- (in books of five tickets) as well as: - One-week ticket (Monday - Sunday), ATS 142.-; whole network but not during night; - "24-hours" network pass , ATS 50.-; - "72-hour" network pass , ATS 130.-; - 8-day ticket "Umweltticket", ATS 265.- (containing 8 days of travel, to be punched for each day it is used; can also be used by more than one person - just punch once for each person, starting at number 1!); A "TABAK-TRAFIK" is situated in the conference building (near the entrance, next to the tram stop); opening hours: Monday through Friday from 6.00 a.m. to 6.00 p.m. You may also buy the VIENNA CARD: see http://wtv.magwien.gv.at/e/index.htm
BADGE Please wear your badge during the whole conference (including social events).
V INFORMATION
USEFUL TELEPHONE NUMBERS: Dialling prefix: from inside Austria (but outside Vienna): 01 from abroad: int.exit code + 43-1
Conference place: 58801 + Extension Conference desk: Extension 5465 Austropa desk: Extension 5479
AUSTROPA Congress Department: 31680 - 26
Telephone calls abroad must be paid in cash at the conference desk. We recommend to use the automatic telephones (which are also cheaper), situated on the ground floor and 1st floor of the conference building.
XEROX SERVICE: The University copy service ("KOPITU") is situated in the conference building (ground floor); it will be open from 8.00 am - 6.00 pm; prices: ATS 1.- (normal copy), ATS 12.- (transparency), ATS 13.80 (colour copy), ATS 25.- (colour transparency).
PC AND TERMINAL ACCESS: A limited service is available for printing documents on Macintosh and MS-DOS. TERMINAL access to networks is available (Telnet, FTP, Mosaic). Please, contact the Conference Secretariat for more information.
BEFORE YOU LEAVE: — Have you deposited your manuscript for the Proceedings together with the address where you wish to get the proofs and Proceedings?
— A special arrangement has been made with AUSTROPA: for participants, AUSTROPA offers transportation from the Conference place or from your hotel to the Airport, price 200.- ATS.
AFTER THE CONFERENCE, please use again the address of the Institute for High Energy Physics, as before:
Wire Chamber Conference Institut fur Hochenergiephysik Nikolsdorfer Gasse 18 Telephone number: (+ 43 - 1) 544 73 28 - 0 A - 1050 Wien, Austria Telefax: (+ 43 - 1 ) 544 73 28 - 54
VI PROCEEDINGS
Proceedings of the WIRE CHAMBER CONFERENCE, Vienna February 23 - 27,1998
The Proceedings will be published by North-Holland Publishing Company as a special issue (but consecutively numbered) of NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH.
The Proceedings will be edited by W. Bartl, M. Krammer, G. Neuhofer, M. Regler and A. Taurok.
Manuscripts will NOT be accepted if they have been published elsewhere or are expected to be published elsewhere before August 1,1998.
The language is English.
We have been strongly encouraged by NIM to submit the manuscripts in Latex format on floppy discs. The corresponding style or class files together with a detailed write-up can be found on our WEB server http://sunwien.cern.ch. The manuscripts should be prepared in accordance with the standards of the journal (see any issue of NIM).
The final manuscript must be handed in to the editors by the end of the conference. Please contact G. Neuhofer (also on questions how to evaluate the number of pages or in case of other questions or problems). Very important: the originals of the figures are absolutely necessary.
The page limit (four printed pages for contributed papers or for posters, and eight for invited talks, figures included) must be strictly observed.
No copy of the proceedings is included in the reduced Conference fee. Additional copies can be ordered at a reduced price by participants only; they must be paid in advance in cash at the Conference desk (700.- ATS).
VII RECEPTION BY THE MAYOR OF VIENNA
at the
"WIENER RATHAUSKELLER" (Cellar of the VIENNA CITY HALL)
LANNERSALON
Place: Wiener Rathauskeller (Vienna City Hall)
Entrance: Rathausplatz 1,1010 Wien (tram no. 1, 2 or subway U2, station RATHAUS)
Time: Tuesday, February 24, 20.00 h
BY PERSONAL INVITATION ONLY
Please note: The invitation is valid for one person only; its presentation is necessary for admittance to the City Hall. (Please pick up your invitation at the Conference Secretariat on Tuesday morning, February 24) Lounge suit or national costume.
vra CONCERT
Place: "Hofburgkapelle" (Vienna Imperial Chapel) 1010 Wien, Hofburg-Schweizerhof
Time: Wednesday, February 25, 19.30 h
Public Transport: U3 - station "Herrengasse" or A2 - City-bus, station "Michaelerplatz"
Church Choir Music (from Gregorian chant to modern music)
on the occasion of the beginning of the fasting period
and
Baroque Chamber Music (with the original instruments)
performed by
Chorus Viennensis / Choralschola of the Vienna Imperial Chapel (Men's choir of the former Vienna Boy's Choir)
and
Ensemble Tekanemos
IX WINE-TASTING CONFERENCE DINNER
"HEURIGER"
SCHUBEL-AUER (Alter Auerhof 1642)
Place: Kahlenberger StraBe 22 A-l 190 Wien (NuBdorf)
Time: Friday, February 27, 19.30 h
Public Transport: Tram no. D along the RingstraBe to station NuBdorf (final station) ABSTRACTS
VIENNA
WIRECHAMBER CONFERENCE '98 AT9900103
23 February Monday
Gaseous Detectors: Recent Developments and future Mon 14.30| Perspective's IT
CERN, Geneva, Switzerland
Thirty years after the invention of the Multi-Wire Proportional Chamber, and twenty from the first Vienna Wire Chamber Conference, the interest and research efforts devoted to gas detectors are still very conspicuous, as demonstrated by the number of papers submitted to this Conference. Innovative and performing devices have been perfected over the years and used in experiments; more are still being developed today. Amazingly, after one hundred years of continuing studies on gas discharge phenomena, our knowledge on this very complex subject is still improving thanks to the studies motivated by specific instrumental requirements. After a short reminder of the most relevant processes leading to detection (ionization, drift, mul- tiplication, signal induction) I will describe several "tools of trade" that have been developed and are available to model the counting action and to analyze properties of the detectors. As an example, the results of a recent study of the timing proper- ties of Resistive and Parallel Plate Chambers will discussed. Recent results obtained with the NA49 Time Projection Chamber will be presented as an illustration of the extremely powerful pattern recognition properties that can be achieved with gas detectors for complex events at moderate interaction rates. Introduced ten years ago, and after a substantial effort of development, the Micro-Strip Gas Chamber appears to fulfill the needs of the demanding high luminosity trackers; the major advances in this field will be reported, followed by a discussion on discharge prob- lems encountered and possible solutions. Alternative and potentially more powerful geometries such as the micro-gap, narrow-gap and micro-dot chambers will be de- scribed. A new generation of devices exploiting avalanche multiplication in narrow gaps has emerged recently, namely Micromegas, the CAT (Compteur Trous) and the Gas Electron Multiplier (GEM). The last is particularly interesting since it allows to add amplification stages and reach high gains in safe operating conditions. Light and flexible the GEM device can fulfill many different detector requirements; opera- tion in a wide range of conditions and gas pressures has been already demonstrated. Whilst still experimental, these detectors have very promising performances and in- creased reliability in harsh operating conditions Applications in fields other than HEP of these simpler and rugged devices can be anticipated. The number of still open and often controversial subjects of study (as for example the ageing issue), and the continuing imaginative efforts of the experimenters seem to ensure more surprises in the field of gas detectors, and a continuation of the WCC Conference for many years to come. AT9900104
Monday 23 February
Radiation detectors in biological and medical Mon 15.20| applications IT
H.-J. Besch 1
Universitat Siegen, Siegen, Germany
New developments in medical and biological imaging will be presented. In stan- dard X-ray transmission imaging the transition to digital radiography is well under way.Industrial and research developments will be shown, and compared. Progress in positron- and single photon emission tomography (PET and SPECT) using mod- ern scintillators and photo detectors will be discussed, together with the extension of metabolic markers into new fields. The application of synchrotron radiation in cardiac imaging and in mammography will be shown. The use of polarized 3He in nuclear magnetic resonance lung imaging will be demostrated as a non radiative example, as well as the use of ultrasound in cardiac studies. The mutual interde- pendence of object contrast, image contrast, detective quantum efficiency (DQE), modulation transfer function (MTF) and radiation dose will be briefly discussed. In biological applications newly developed detectors for structural research, especially protein crystallography and small angle X-ray scattering, will be compared with standard techniques.
1 invited speaker AT9900105
23 February Monday
A Gas Compact System for Coloured Digital Mon 17.001 Radiography
S. Cadeddua, C. Caligiore0, M. Cariaa. A. Laia, D. Lo Prestib, S. Panebiancob, C. Pettab, P. Porcua, N. Randazzob, P. Randaccioa, S. Reitoband G.V.Russob,
*INFN Sezione di Cagliari/Dipartimento di Fisica, University of Cagliari, Cagliari, Italy hINFN Sezione di Catania/Dipartimento di Fisica University of Catania, Catania, Italy c Centro sidliano di fisica nucleare e struttura della materia Catania, Catania, Italy
We present a compact system for the digital radiography, based on GaAs detectors. The system is based on a VLSI circuit with analog and digital functions for the acquisition of radiological images in a wide range of applications. The operating principle and the design are presented, together with simulation on the performances for digital radiological images. The analog pixel readout is made out of a charge sensitive preamplifier with ca- pacitive feedback. The signal to noise ratio figure is improved thanks to a CR-RC2 shaper amplifier with active filter; while the power-noise figure is as low as 500e- ENC for a power loss of less than l,5mW/channel, thanks to an adequate capacitive coupling. Each channel of the digital part is made out of pulse height analyzer and a memory. This allows a spectrocopic analysis of all the photons detected by each single pixel. In order to minimize the dimensions of each single acquisition channel, every channel memory is made out of partial counters, periodically read out by another istogram- ming circuit which sums up all the memories contents on a common memory. This memory contains then, the acquired images, each recorded with the correponding photon energy. The operating principle and the design are presented, together with simulation on the performances for digital radiological images. First results on a scanning system with a pixel array are also presented and discussed in terms of the images quality and evaluation of the Signal to Contrast Ratio. AT9900106
Monday 23 February
A highly sensitive two-line detector with large dynamic range for intravenous coronary angiography
M. Lohmanna, H.J. Bescha, W.-R. Dixb, 0. Diinger", M. Jungb, R.H. Menka and B. Reimeb aFachbereich 7 Physik der Universitat Gesamthochschule Siegen, Siegen, Germany bHamburger Synchrotronstrahlungslabor HASYLAB am DESY
The medical community is highly interested in methods for non-invasive imaging of coronary arteries. One method under development is dichromography. This method allows imaging of small fast moving subjects like the coronary arteries inclusive distal parts and sidebranches after intravenous injection of contrast material. Two images with monochromatic x-rays at energies just below and above the K-edge of iodine (33.17 keV) are simultaneously taken. After logarithmic subtraction coro- nary arteries down to 0.7 mm diameter with extremely low iodine concentrations (10 mg/ml) become visible. In the Hamburger Synchrotronstrahlungslabor HASYLAB at DESY in Hamburg, Germany the system NIKOS was developed for dichromography. In this system the detector is one of the main components. This two line scan detector is a ionization chamber for the two energies. The two gaps are separeted at the drift cathode. A Frisch-grid each for shielding the ions in a distance of 3mm defines the conversion room. The 336 anode strips per line with a length of 56mm in the direction of the beam are connected to the front end electronics. The parameters of the last version of the detector are: equivalent noise of about two photons, dynamic range of 300000:1, readout time for the two lines (672 pixel) 0.25ms. AT9900107
23 February Monday
Gas amplifying hole structures with resistive position Mon 17.501 encoding: A new concept for a high rate imaging pixel detector
A. Sarvestania. H.J. Bescha, M. Junka, W. Meinera, N. Sauera, R. Stiehlera, A.H. Walentaa and R.H. Menkb
* Universitat Siegen, Fachbereich Physik, Siegen, Germany bELETTRA, Sincrotrone Trieste, Trieste, Italy
Promising recent developments in gas amplifying hole structures were accompa- nied by a lack of appropriate read-out structures. Here, a new hole structure is presented combined with a two dimensional resistive position encoding device. The investigations are focused on applications with high rate X-ray sources, including studies of position resolution, gas gain, rate capability, drift field influence and high pressure operation. In addition, first results of the imaging performance will be reported. Due to the promising results of these investigations it is expected that this kind of detector will be used in the future in many applications which were, up to now, dominated by conventional multiwire or microstrip chambers. AT9900108
Monday 23 February
The ALPHA Magnetic Spectrometer Experiment Mon 18.151
G. VierteP for the AMS Collaboration
*ETH Zurich, Zurich, Switzerland
The Alpha Magnetic Spectrometer (AMS) Experiment will be the first sensitive magnetic spectrometer in space. It is scheduled to be installed on the International Space Station (ISSA) January 17, 2002 via the shuttle ATLANTIS. It will stay on the space station for 3 to 5 years and will perform pioneering measurements of the charged particle composition to answer some of the fundamental questions in the particle physics and astrophysics such as : Why are 90 univers not observable? Wether there exists antimatter in the univers? What are the properties of Cosmic Rays? Before installation on the ISSA, AMS will fly on the shuttle DISCOVERY on May 29, 1998, for the period of 10 days. This will enable AMS to perform a first measurement of charged particle cosmic particles and a test of the apparatus. The AMS detector for the MAY 29 flight will have five major elements : A perma- nent magnet, a Silicon microstrip tracker, a scintillator time of flight hodoscope, a scintillator anticoincidence counter and an Aerogel Cerenkov threshold counter. In addition there are electronics and support infrastructure and interfaces. AT9900109 24 February Tuesday
High Resolution Electro-magnetic Calorimetry with Noble Liquids
D. Schinzel
CERN, Geneva, Switzerland
Current sensitive, fast electromagnetic calorimeters with excellent energy and time resolution using noble liquids have been developed either for collider experiments or fixed target experiments. The fine grain tower structure of these calorimeters allow high rates and yield very good spatial resolution. Performance and results of the ATLAS accordion calorimeter (sampling calorimeter), of the NA48 liquid Krypton calorimeter (quasi-homogeneous calorimeter) and of ICARUS (homogeneous detec- tor) are presented. Starting from first principles, quantities which may significantly influence the energy resolution in addition to shower fluctuations and longitudinal leakage are discussed. Constructional and operational aspects, including cryogenics and purification are presented. AT9900110
Tuesday 24 February
High accuracy measurement of photon position in liquid krypton calorimeter
S. Akmadaliev, V. Malyshev, A. Maslennikov, A. Onuchin; S. Peleganchuk, G. Pospelov and Y. Tikhonov
Budker Institute of Nuclear Physics, Novosibirsk, Russia
Fine granulated calorimeter based on LKR has been tested at tagged photon beam of VEPP-4M storage ring in energy range of 100-4000 MEV. Position of photons was measured in strip structure with strip width of 10 mm. Position resolution of 1.0 mm was achieved in agreement with simulation. It is about 5 times better than for best crystallic calorimeters. AT9900111
24 February Tuesday
The Construction of the KLOE Drift Chamber Tue 10.15 f
G. Bencivenni
Laboratori Nazionali di Frascati, Frascati, Italy
The tracking detector of the KLOE experiment is a large volume drift chamber designed to contain most of the decays of KL produced at the DAFNE ^-Factory, All construction choices have been driven by the need of measuring kaon decays with high and well controlled efficiency and a spatial resolution < 200 /um, while minimising at the same time multiple scattering and photon conversion. The gas volume (~45 m3) is uniformely filled with approximately square drift cells arranged in alternated stereo views. All materials are chosen to ensure maximum trasparency and the chamber is filled with a ultralight gas mixture, 90% He + 10% iCiHio- The 25 /an tungsten sense wires (12,582) and the 80 ^m Al-5056wires (38,622 field, 936 guard wires) are strung between two thin carbon fiber end piates whose deformation is tuned during stringing to compensate for the wires load. The design of the chamber, choice of materials, wiring technique, gas volume sealing and wire connections are described in detail as well as the quality tests during the construction. The chamber is presently under test with cosmic rays, first results of its operation are presented. AT9900112
Tuesday 24 February
Drift Chambers for PHENIX Central Tracking System
V, Riabova'b
*HEPD, PNPI, Gatchina, Russia bThe Drift Chamber group of the PHENIX Collaboration (PNPI, Stony Brook, LLNL, BNL)
The Drift Chamber (DC) is the part of central tracking system of the PHENIX detector. DC construction consists of two independent arcs. Each of them covers an active area ±0.35 on pseudorapidity and 90° on azimuthal angle
10 AT9900113
24 February Tuesday
The Region One Drift Chamber for the CLAS Tue 11.551 Spectrometer
D.S. Carman a. S.A. Dytmanb. R. Magahiza, M.D. Mestayerd, R. Miskimen6, J.A. Mueller6, R.A. Schumachera. D.J. Tedeschi0 and R.A. Thompson13
a Carnegie Mellon University, Pittsburgh, Pennsylvania, USA b University of Pittsburgh, Pittsburgh, Pennsylvania, USA c University of South Carolina, Columbia, South Carolina, USA d Jefferson Laboratory, Newport News, Virginia, USA e University of Massachusetts, Amherst, Massachusetts, USA
The Region One drift chamber is the innermost of three nested drift chamber pack- ages of the CLAS spectrometer at Thomas Jefferson National Accelerator Facility. The detector was optimized for the CLAS toroidal magnet geometry, and has over 7500 drift cells that span a polar angular range of 8° to 140° and nearly 80% of the azimuth. It consists of six identical wedge-shaped sectors integrated into a single unit. Each sector has thin and relatively weak aluminum endplates which support the large mechanical loads from the wire tensions and associated readout hardware. The unique feature of the detector is its self-supporting design, wherein the wire tensions of neighboring sectors balance each other without massive structural sup- port. Many design factors were crucial to consider in order to achieve tight wire tension tolerances. These include effects such as endplate deformation due to the wire tensions and gravitational sag, as well as the components and procedures nec- essary for integrating six separate sectors into one self-supporting unit. This talk will focus on the design and engineering challenges of the Region One detector, as well as report on the results of the recently completed detector commissioning runs used to study system performance within the CLAS spectometer. AT9900114
Tuesday 24 February
The BaBar Drift Chamber: Status and Test Results Tue 12.20 f
G. Sciollaa for the BaBar Drift Chamber Collaboration
^Stanford Linear Accelerator Center, Stanford. USA
The central drift chamber for the BaBar detector at the SLAC PEP-II B-factory is based on a hexagonal small-cell design arranged in 40 layers. The gas is a 80%: 20% mixture of Helium:isobutane. The pulse-height and timing electronics are mounted directly on the chamber end-plate. At present, the mechanical assembly of the chamber has been completed and the electronics has been sent for fabrication. The chamber is expected to be fully oper- ational for cosmic ray tests in summer 1998. A full length prototype of the BaBar Drift Chamber has been built at SLAC . The analysis of the cosmic ray events confirms that both the drift chamber and the electronics design meet the performance goals for the BaBar central tracker.
12 AT9900115
24 February Tuesday
Microstrip Gas Chambers : Recent developments, The 14.001 radiation damage and long term behaviour IT
B. Schmidt
Physikalisches Institut, Universitat Heidelberg, Heidelberg, Germany
In the past years the technology of Microstrip Gas Chambers (MSGC) has made considerable progress offering a rich field of possible applications in various fields of research. MSGC are used to detect neutrons, x-rays, synchrotron radiation and VUV light as well as the full range of ionising particles in nuclear and high energy physics. A variety of systematic studies led to a considerable increase in understanding of the functional principle and limiting parameters and enabled improved performances. In view of the large (HBRA-B) and very large (CMS) detector systems planning to use MSGC in intense hadronic particle fluxes, the question of radiation hardness and long term stability is of special importance. The problem of micro discharges, induced by heavy ionising particles and destroying the electrode structure, turned out to be a major limitation to the applicability of MSGC in hadronic beams and demanded for new and revised solutions. The present status and future perspectives of the various technologies will be discussed.
13 AT9900116
Tuesday 24 February
The development of MSGC for the CMS central tracking system
R. Bellazzinia for the CMS collaboration
*INFN S. Piero a Grado - Pisa, Pisa, Italy
Results will be presented of laboratory and beam tests of the performance prototype of the MSGC system of the CMS experiment at LHC. Emphasys will be given on the recent tests with high rate hadron beams both at CERN and PSI. Progress on the MSGC module definition and other system aspect will be also presented.
14 AT9900117
24 February Tuesday
Design, construction and test of an MSGC module for Tue 15.15 I the CMS forward tracker
a a a a S. Bachmann , F. BeisseP, C Camps , V. Commichau , G. Fliigge ; K. Hangartera, R. Ischebecka, J. Krempa, D. Mackea, A. Nowacka. 0, Pootha, R. Schultea and M. Tonutti3 *-III.Physikalisches Institut, RWTH Aachen, Germany
The IILPhysikalische Institut, RWTH Aachen developed a closed MSGC detector module for the CMS forward tracker. Special emphasis is layed on safe treatment of the substrate surfaces by closing the detection volume at an early construction stage directly after the alignment of the MSGC substrates inside the module. The banana shaped module houses four substrates with wedge shaped patterns without dead area and 2048 read out channels on 800 cm2. A special alignment tool and glueing jig combination provides a precise, fast and safe production procedure and is presented in this talk. The concept forsees the frontend electronic and HV adapter outside the detection volume to avoid pollution of the counting gas. Three prototypes read out by the PreMuxl28 frontend chip were tested in the laboratory and particle beam experiments.
15 AT9900118
Tuesday 24 February
Performance of the Small Gap Chamber under high irradiation of pions or X-rays
V. Chorowicz, J.F. Clergeau, D. Contardo. R. Haroutunian, L. Mirabito, S. Muanza and G. Smadja
Institut de Physique Nucleaire de Lyon. Lyon, France,
The Small Gap Chamber is a MicroStrip Gas Chamber with an anode-cathode separation of 10 /um burried in a polyimide layer overlapping 1 /an at the edge of the strips. The detector measures minimum ionizing particles with an efficiency plateau of 100 Volts. It does not suffer from a gain loss under an irradiation of up to 105 X- rays/mm2/s. It is therefore a well suited alternative to avoid the surface treatment of the MSGC's. The behaviour in a high intensity beam of 400 MeV pions has been tested at PSI. The study is based on the monitoring of the beam profile and of the number of streamers. The latter measurement was performed with a fast nanoampermeter connected to the cathodes. During the test, a signal to noise ratio suitable for the CMS experiment was achieved without damages. A high voltage scan allows a preliminary evaluation of the efficiency plateau at the PSI beam conditions.
16 AT9900119
24 February Tuesday-
Comparative Studies of MSGC and MSGC-GEM Tue 16.551 Detectors
J.-M. Brom
IRES Strasbourg, UHA Mulhouse. France
We describe laboratory and beam tests comparative measurements of identical MSGC and GEM-equipped MSGC's. Both kind of detectors have been tested un- der exactly the same conditions, using radioactive sources and muons beams. The principal aim of this comparative study was to evaluate the operating conditions for the same resulting gain. Results on efficiencies and spatial resolution are presented. Possible applications of GEM-equipped MSGC's in the LHC environnement and needed R&D studies will be discussed.
17 AT9900120
Tuesday 24 February
Operation of Micro Strip Gas Counters with DME Tue 17.201 based gas mixtures
0, Bouhalia. F. Udoa, W. Van Donincka, L. Van Lanckera, C. Vander Veldea, P. Vanlaera, V. Zhukova, W. Beaumontb, T. Beckers b, J. De Troyb, C. Van Dyckb and F. Verbeureb
*IIHE,ULB-VUB, Brussels, Belgium hUIA, Antwerp, Belgium
We report on the performance of MicroStrip Gas Counters (MSGC) filled with several DME based gas mixtures. We present measurement of signal amplitude, detection efficiency and spatial resolution for minimum ionising particles(MIP's) made with a cosmic rays hodoscope. We also show measurements, performed in a laser setup, of electron drift velocity and transverse diffusion as a function of drift field. This study shows that the triple gas mixture Ne/DME/CC>2 40/40/20 % is a good step closer to an ideal gas to operate MSGC system at rates and magnetic fields required for trackers in modern hadron experiments. Stable operation for MIP's with full efficiency is obtained for a long range of cathode strip voltage of 100 V starting at low value. The presence of CO2 ensures fast electron collection.
18 AT9900121
24 February Tuesday
Further Developments and Beam Tests of the Gas Tue 17.45 I Electron Multiplier (GEM)
J. Benlloch, A. Bressan, M. Capeans, M. Gruwe, M. Hoch, J.C. Labbe, A. Placci, L. Ropelewski, F. Sauli
CERN, Geneva, Switzerland
We describe the development and operation of the Gas Electron Multiplier, a thin insulating foil metallized on both sides and perforated by a regular pattern of small holes. The mesh is incorporated in the gas volume of an active detector to provide, after application of a difference of potential between electrodes, a first amplification channel for electrons. We report on the basic properties of GEMs manufactured in different geometries and operated in several gas mixtures as well as, if coupled to a high rate device, on their long-term stability after accumulation of charge equivalent to several years of operation in the future high luminosity experiments. Optimized GEMs reach gains over 2000 at confortable operating voltages, permitting the de- tection of ionizing tracks without other amplyfing elements but on a cheap, simple printed circuit board (PC), opening new posibilities for detector design. We have also evaluated the detection efficiency, time and spatial resolution of GEMs coupled to Micro Strip gas Chambers or PC boards in particle beams in presence of a strong magnetic field.
19 AT9900122
Tuesday 24 February
First results on the GEM operated at low gas pressures Tue 18.10 f
A. Breskina, R. Chechika, G. Gartya, J. Mattouta, E. Shefera and F. Saulib
^Weizmann Institute of Science, Rehovot 76100, Israel bCERN, Division PPE, Geneva, Switzerland
We report on the properties of Gas Electron Multipliers (GEM) operated at pres- sures of 10-40 torr of hydrocarbons. Despite the small dimensions of the multiplying apertures, namely 100 (m in diameter circular holes in a 50 (m thick copper cladded Kapton, and the low gas density, charge gains of the order of 2000 were measured in this low-pressure range. Fast current pulses were recorded with single electrons in a MWPC preceded by the GEM, measuring 10 ns at the base. It was found that the GEM does not affect the timing properties of the combined detector. A reduction in photon feedback and gain enhancement were measured with a GEM- preceded MWPC coupled to a Csl photocathode. We will discuss the properties of low-pressure GEM detectors and their important role in fast gaseous imaging devices for single electrons and single photons.
20 AT9900123
25 February Wednesday
The development of MICROMEGAS, a novel very high-rate position sensitive detector
I. Giomataris
CEA Saclay, Gif-Sur-Yvette Cedex, France
A new class of gaseous microstrip detector called "MICROMEGAS" is under de- velopment in Saclay. We will describe in detail the principle and basic properties of this detector, progress on its optimisation as well as its performance in high rate beam : - high rate capability > 109/mm2/s - spatial resolution (< 40 fj.m) - time resolution < 5 ns - radiation hardness - high efficiency for minimum ionising particles - high gain operation > 105 - performaces with heavy and new gas mixtures - low radiation length We will discuss the use of this detector in high fluence radiation environment near the interaction region in future high luminosity accelerators. Future developments to achieve its ultime space and time resolution will be reported.
21 AT9900124
Wednesday 25 February
Test of micromegas detector Wed 9.50 as LHC tracking chambers
J. P. Cussonneaua, P. Lautridoua, L. Luquina, V. Metiviera, A. Rahmania. V. Ramilliena and T. Reposeura
*Laboratoire SUBATECH, UMR Universite - Ecoles des Mines - IN2P3/CNRS, Nantes Cedex OS, France
An innovative solution for tracking chambers, based on the detector MI- CROMEGAS, is investigated at SUBATECH. Three prototypes have been con- structed and tested in the 3 GeV/c pion beam of the CERN PS. This paper de- scribes the caracteristics of these detectors, and the set-up used for the tracking test. First measurement concerning resolution as a function of gaz mixture, high voltage and the angular incidence of the particle are presented and discussed. The results obtained concermng the efficiency and the resolution (< 50p,m), satisfying the requirement of most of the present LHC trackers, a possible integration to large surface detector can be presented. First view of a large prototype under development at SUBATECH will be shown.
22 AT9900125
25 February Wednesday
Experimental Results from a Microdot Detector Wed 10.151 Overcoated with a Smiconducting Layer.
S.F. Biagi. D. Duxbury, E. Gabathuler
Physics Department, University of Liverpool, Liverpool, United Kingdom
A microdot detector has been overcoated with a boron doped amorphous silicon carbide semiconductive layer. The stable operation of the device, in mixtures of argon, neon or helium mixed with DME, is shown at both high gains of up to 100,000 and at counting rates of up to 106/mm2/sec. radiation damage tests give a lifetime of over 120mc/cm. using a test system with many metres of plastic gas piping.
23 AT9900126
Wednesday 25 February
Examples of calculations for gaseous detectors
R. Veenhof
Nikhef, Amsterdam, The Netherlands
I would like to present the physical and mathematical background to some calcula- tions for gaseous detectors done over the last year. The related measurements are hopefully presented at this conference: (1) a study and optimisation of the resolu- tion of the Atlas muon tubes, (2) the effect of space charge on the r(t) relations of these tubes, (3) the coupled movement of several wires in a RICH proposed for Alice, (4) drift properties and avalanche development in GEM foils, (5) diffusion studies in Micromegas detectors. These calculations were done with the help of a series of computer programs (Magboltz, Heed, Maxwell), interfaced with Garfield which in the process has considerably been modified and extended.
24 AT9900127
25 February Wednesday
Rate and gain limitations of MGC's and MSGC's Wed 11.55| combined with GEM or other preamplification structures
P. Fontea, V. Peskov b and B.D. Ramsey,-b
&LIP/Coimbra University and ESEC, Portugal hNASA /Marshall Space Flight Center. Huntsville, USA
We have studied the rate and gain limits of MGC's and MSGC's when combined with various preamlification structures: GEM, PPAC or MICROMBGAS-type. Mea- surements were done both with x-rays and alpha particles at various geometries and in different gas mixtures at pressures 0.05-10 atm. The results obtained varied signif- icantly with gas mixtures and pressures, but some general features can be identified. We found that an increase in total gain is possible due to additional diffusion of the primary charge cloud in the preamplification structure, which lowers the charge density by at least a factor of 10. At low rates, the operation of the system (de- tector-H preamplification structure) is limited mostly by the space charge. In this case the total gain is restricted to values < 106, after which a strong deviation from the proportional region was observed, together with sparking. At high rates, sur- face streamers and "surface excitation" effects may lower the maximum achievable gain both in the preamplification structures and the detectors. Our studies show that this "surface excitation" is actually a lowering of a material's ( metallic or dielectric) work function under intense ion bombardment. It may be accompanied by burst-type electron emission from the surfaces, which affects detector operation and causes sparking. This effect was studied in detail and its role in breakdowns of gaseous detectors and preamlification structures was analysed. As a results of these studies a safe, spark-free, operation zone for each system (detector+preamplification structure) in the rate -gain coordinate plane was identified.
25 AT9900128
Wednesday 25 February
Infrared emission induced by ionizing particles and by electron drifting in gas media
G. Carugno
INFN-Padova, Padova, Italy
The emission of infrared photons has been studied in a ionization chamber (I.C.) filled with standard gases. The primary scintillation light has been analyzed and results on the infrared light yield are reported. The secondary scintillation light produced by the electron drifting in the gases media is presented as a function of Electric field versus pressure. The emission of infrared photons has been observed in an ionization chamber irradi- ated with a proton beam of a few Mev. The primary emission light (no field applied) has been observed in gases as: Argon, Xenon and with a weaker signal in Helium. The infrared light produced by the electron drifting is present in the following gases: Argon, Xenon and Nitrogen. The wavelength of the emitted light versus the applied field will be presented. The very low energy quanta involved with infrared (0.1 eV) open the possibility to reach good energy resolution.
26 AT9900129
26 February Thursday
Semiconductor Trackers for Future Particle Physics Thu 9.00 | Detectors IT
W. Trischuk
University of Toronto, Department of Physics, Toronto. Ontario, Canada
Plans to use silicon detectors in high energy particle trackers at upcoming experi- ments are reviewed. This will include a description of the detector geometries being considered as well as the main experimental challenge in these applications: radi- ation hardness. Our understanding of the phenomena which limit silicon detector lifetime will be outlined and I will summarise how long these devices can be ex- pected to operate. After listing the compromises entailed by the use of silicon I will describe an alternative: diamond. The inherent properties of diamond make it an ideal material for tracking detectors especially in the high rate and radiation environments neax the collision point in future colliders. We have constructed and tested micro-strip and pixel detectors using high quality Chemical Vapour Deposited (CVD) diamond. While this is an important first step a number of issues remain: ensuring the radiation hardness of the material is sufficient to survive in regions where silicon cannot and maximising the charge observed when a charged particle traverses the material. Work in both of these directions is described.
27 AT9900130
Thursday 26 February
The CMS barrel silicon tracker Thu 9.50 "
D. Biselloa for the CMS silicon tracker collaboration
a University of Padova, Padova, Italy
The final design for the barrel silicon tracker of the CMS experiment will be pre- sented. Major challenges on the mechanics, cooling, and radiation hardened silicon detector choice will be outlined. Overall preformances in terms of expected oc- cupancy, material budget, momentum resolution, pattern recognition and inpact parameter resolution will be addressed.
28 AT9900131
26 February Thursday
The new Silicon Vertex Detector for the CDF Thu 10.151 experiment
N. Bacchettaa for the SVXII-CDF collaboration
*INFN Padova, Padova, Italy
A new Silicon Vertex Detector (SVXII) for the CDF experiment at the Fermilab Tevatron collider is described. The SVXII is formed by 5 layers of double sided silicon microstrip detectors at radii from 2.45 cm to 10.5 cm providing geometric coverage up to 2 units of pseudorapidity. The reduced distance to the interaction region implies that the detectors have to operate in a high radiation level. Fac- ing this environment and addressing the needs for compactness in the structure, minimization of material, mechanical and temperature stability and the 0.4 * 106 channels to be readout in a dead-timeless mode, represent the biggest challenges of this project.
29 AT9900132
Thursday 26 February
Layout and tests of silicon pad detectors for the PHOBOS experiment at RHIC
H. Pernegger* for the PHOBOS collaboration b
aMassachusetts Insitute of Technology, USA bArgonne National Laboratory, USA, Brookhaven National Laboratory, USA, Case Western Reserve University, USA, Institute of Nuclear Physics Krakow, Poland, Jagiellonian University Krakow, Poland, Massachusetts Insitute of Technology, USA, National Central University, Taiwan, Oak Ridge National Laboratory, USA, University of Rochester, USA, University of Illinois Chicago, USA, University of Maryland, USA, Yale University, USA
The PHOBOS experiment at RHIC, which is currently under construction, is de- signed to measure the particle multiplicity and to reconstruct low momentum tracks in heavy ion Au-Au collisions. Both tasks, the multiplicity measurement and the track reconstruction, are accompished with silicon pad detectors, which can cope with the high occupancy near the vertex and provide sufficient spatial resolution for track reconstruction. The silicon pad detectors are single-side devices with up to 1540 pads per detector. A special double-metal readout scheme for pad detectors provides a cost-effective method to connect detectors with different pad geome- tries to identical standard VLSI electronics. Several different pad geometries have been designed and tested to optimize the pulse height and position measurement. Results of tests on the signal response and detector parameters for different pad configurations will be presented.
30 AT9900133
26 February Thursday
GLAST, the Gamma Large Area SPACE Telescope Thu 11.55 f
H. Sadrozinski
UC Santa Cruz, Santa Cruz, USA
GLAST is a new NASA mission to probe the signals from the most energetic sources in the sky. Gamma's with energy between 30MeV and 20GeV are tracked in a large aperture converter/tracker with the help of silicon strip detectors. Their energy is than determined with a calorimeter. These sources might be variable in time and could provide information about the emission of energies on a short time scale. The GLAST instrument is divided into 25 towers, and each tower consists of 16 layers of silicon microstrip detectors. This unprecedented scope of a silicon tracker (totaling 87 m2) poses difficult technical challenges: 1) Construction and alignment to a few tens of microns. 2) Reliability in the harsh space environment 3) low power, low noise electronics for the 1.5M channels. Prototype detectors and electronics readout chips have been tested both on the bench and in a beam test which allows prediction of the ultimate performance of the tracker. The power level achieved is about 10 times lower than in previous ASIC's. Motivation of the mission, various performance tests and anticipated properties of the instrument will be discussed.
31 AT9900134
Thursday 26February
High Performance Imaging Thermal Neutron Detectors
V. Radeka, N.A. Schaknowski, G.C, Smith and B. Yu,
Brookhaven National Laboratory, Upton, NY, USA
Spallation neutron sources require two-dimensional detectors for a significant pro- portion of experiments. It is essential that these detectors possess good time resolu- tion to determine the neutron energy. A range of detectors based on gas proportional chambers, with low noise encoding electronics, has been fabricated at this labora- tory, with properties well suited for spallation sources. These detectors have out- standing qualities in terms of dynamic range and stability of both recorded neutron positions and response (efficiency), in addition to normal attributes such as good position resolution, high efficiency and insensitivity to gamma-rays. We review here some of the major characteristics of the detectors, describe recent advances, and illustrate their high level of performance with neutron scattering results. Special- ized efforts are required for their development and additional opportunities at new spallation sources will need continued advances in detector performance.
32 AT9900135 26 February Thursday
Frontend Electronics and Radiation Hardness Issues
P. Weilhammer
CERN, Geneva, Switzerland
Signals from radiation sensors, generally current pulses, can have very different properties in time structure and amplitude. In most sensors signals are small and need electronic amplification. The very demanding requirements of particle detec- tion in high energy physics experiments have in recent times led to an escalation of new detectors. With the advent of VLSI electronics it has become possible to build extremely performant and sophisticated readout electronics for complex detection systems. In particular for solid state detectors, which themselves are built using the technology developed for IC electronics, very complex VLSI front-end chips have been designed and implemented. In this presentation an overview of the design, architecture and performance of several typical front-end chips, which have recently been built for the readout of detectors will be given. Emphasis is put on front-ends for solid state tracking detectors for experiments at future high energy and high lu- minosity colliders. Other applications, e.g. in astroparticle physics and in biological and medical imaging will also be mentioned. The implication of radiation damage of frontend chips in the high luminosity collider environment will be discussed. A short overview of experience with some currently commercially available radiation hard technologies will be presented.
33 111111111111 AT9900136
Thursday 26 February
A 40 MHz Pipelined Trigger for K° -» 2TT° Decays for Thu 14.501 the CERN NA48 Experiment
C. Avanzinia, G.D. Barra, P. Calafiuraa, M. Cirilli\ F. Costantinia, a c a a a D. Cundy , H. Dibon , G. Fischer . F. Formenti , B. Gorini ; 3 a e 0 a e a B. Hallgren , W. Iwanski ' , M. Jeitler , P. Kapusta ' ; F. Laico , G. Laverrierea, G. Magazzua, M. Markytan0, I. Mikulec0, F. Morsania. c 0 a d a G. Neuhofer . M. Pernicka , G.M. Pierazzini , M. Porcu ; D. Rizzi , F. Rossid, M. Sozzia, A. Taurokc, R. Tripiccionea, M. Velascoa, 0. Vossnacka, H. Wahla and M. Ziolkowskia'e
*INFN, sezione di Pisa, Pisa, Italy hCERN, Geneva, Switzerland cInstitut fur Hochenergiephysik, Vienna, Austria d Universitd di Ferrara, Ferrara, Italy e On leave from: Institute of Nuclear Physics, Cracow, Poland
NA48 is a high-precision experiment to measure direct CP violation in the neutral kaon system (KL,K$) by determining the CP violation parameter Re(s'/e) with a precision of 2 x 10~4. The relevant neutral decays KL^S —• 27r° —> 47 are detected by a quasi-homogeneous electro-magnetic Liquid Krypton (LKr) calorimeter with a longitudinal readout structure. The described trigger selects 2n° events from K\ and K% decays and suppresses dominant decays from K\ —> 37r°. The developed trigger system is implemented in a "dead-time free': pipeline to allow laxge rate reduction and high trigger efficiency. The trigger decision is based on the information from «13340 cells of the LKr calorimeter. The calorimeter information is summed, digitised with 40 MHz and digitally filtered to generate 64 X and 64 Y projections. This information is used to calculate at each clock cycle the number of peaks, the total energy and the first and second moments of energy for both projections. A programmable look-up table subsequently computes online the kaon lifetime and performs an event selection. The system is described and the excellent performances achieved during 1997 data taking period are discussed.
34 AT9900137
26 February Thursday
New development on Resistive Plate Chambers for Thu 15.151 high rate operation
H. Czyrkowskia, R. Dabrowskia, M. Cwioka, W. Dommika. J. Krolikowskia. P. Majewskia and M. G6rskib
"•Institute of Experimental Physics, Warsaw University, Warsaw, Poland hSo!tan Institute of Nuclear Studies, Warsaw, Poland
It is demonstrated that a gas detector with parallel resistive electrodes has intrinsic capability of efficient detection at high particle fluxes. The use of a low resistivity material for the electrodes leads to stable operation of the detector at radiation rates as high as 7 kHz/cm2 of the detector area. Inverted Double Gap Resistive Plate Chamber made out of special bakelite of low resistivity - p = 5 • 108f2cm, reaches efficiency plateau of width exceeding 500 V for the highest beam intensity used. Gas mixtures containing a majority of so called "green freons" - C2H2F4 or C2HF5, assure stable avalanche amplification with time resolution about 2 ns, only slightly dependent on the particle flux. Measurements with strong 137Cs source, performed in the Gamma Irradiation Facility at CERN, confirm the stability of parameters in continuous radiation flux up to at least 5 kHz/cm2 of useful flux (gamma ray conversion with ionizing electron in a single gap of a RPC). The average pulse arrival time changes by less than 3 ns with the incoming flux in the range expected for the CMS experiment.
35 AT9900138
Thursday 26 February
Transient Behaviour and Rate Effects in Resistive Thu 16.30 Detectors
M.M, Fragaa, R. Ferreira Marques*. E.P. de Lima». A.J.P.L. Policarpoa, C.C. Buenob, J.A.C. Goncalvesb. M. Damy de S.Santosb, S. Mendiratta0 and L. Costa0
^Laboratorio de Instrumentaçâo e Física Experimental de Partículas Departamento de Física. Universidade de Coimbra, Coimbra, Portugal ^Instituto de Pesquisas Energéticas e Nucleares - Comissáo Nacional de Energía Nuclear, Sao Paulo, Brasil Departamento de Física, Pontificia Universidade Católica de Sao Paulo, Sao Paulo, Brasil cDepartamento de Física, Universidade de Aveiro. Aveiro, Portugal
Most of the studies carried out so far about the dependence of detection efficiency (or charge gain) of resistive detectors on counting rate, particularly concerning RPCs, have assumed stationary regimes. In the present work we report on studies of tran- sient behaviour of detectors with resistive electrodes carried out for various mate- rials, counting rates, charge gains and detector geometries. We show that in some cases the time decay curves can be fitted by a single exponential plus a constant term, while in others (higher charge gains or higher counting rates) a sum of two or even three exponentials plus the constant term is needed. A study of the electric properties of some resistive materials used is also presented, and a comparison is made between these results and the data obtained from the detectors operating un- der irradiation. A physical interpretation of the mechanisms involved is attempted and a simple model is proposed.
36 AT9900139
26 February Thursday
The multigap and the multi-microgap RPC's. Its Thu 16.551 applications in high rate environments
E. Cerron Zeballosb'\ D. Hatzifotiadoub'\ J. Lamas-Valverdeb''. J. Roberts b, E. Platnerb, M.C.S. Williams b'2 and A. Zichichic'b
*CERN, PPE Division, Geneva, Switzerland hRice University, Texas, USA cUniversity of Bologna, Bologna, Italy
Resistive Plate Chambres (RPC) have been chosen for the muon trigger device by various LHC experiments. It is necessary to operate the single RPC in avalanche mode to obtain high efficiency at elevated particle fluxes. We have tested this mode of operation with a 2 mm gap RPC using gas mixtures containing C2F4H2 and C2F5H. We have found that the freon C2F5H has better properties than C2F4H2, however the rate capability of the single RPC with C2F5H is limitated to already 200 Hz/cm2 and the large time-walk with voltage could limit the time resolution for large RPCs systems. We have developed the Multigap RPC and the Multi- Microgap RPC. The excellent time resolution, small time walk and extremely good rate capability makes this a very interesting device for LHC applications.
1 World Laboratory, Lausanne, Switzerland 2 INFN Bologna, Bologna, Italy
37 AT9900140
Thursday 26 February
A mini-TPC for the SLAC B-Factory Commissioning
R. Cizerona, A. Duranda. T.L. Geldb, V, Lepeltiera, B. Meadowsb, M. Ronanc, S. Sena>1. A. Valassia and G. Wormsera
*Laboratoire de I'Accelerateur Lineaire, IN2P3-CNRS et Universite de Paris-Sud, Orsay, France b University of Cincinnati, Cincinnati, OH, USA, cLawrence Berkeley National Laboratory, Berkeley. CA, USA,
A mini-TPC has been developed for use in PEP-II beam commissioning and back- ground studies relevant for the BaBar detector. In this application a TPC offers several advantages: multihit tracking, intrinsic 3D information, superior pattern recognition and dE/dx measurements to help separate hadron and electron compo- nents in the background. The mini-TPC was constructed to be simple, small and robust, and to have the ability to work in a high rate environment. The TPC has been designed to measure accurately the intensity, the origin and the composition of background particles coming from the two PBP-II beams. It has been successfully tested in a 6 GeV/c beam at CERN at intensities up to 106 cm"2. Preliminary results show a spatial resolution better than 500 ^m, and a dE/dx resolution better than 30%. The mini-TPC is now installed near the intersecting region of PEP-II and will be operated during the 1998 PEP-II commissioning runs, first with only the high energy electron beam and then, after installation at the interaction point, with both colliding beams.
Present address: University of Colorado, Boulder. CO, USA,
38 AT9900141
26 February Thursday
Development of a TPC detector for the ALICE Thu 17.451 Experiment.
J. Bachlera, J. Bracinika. H.G. Fischer*, M. Flammiera, J.C. Legranda, a a a 0 L. Musa , M. Pikna : B. Sitar and P. Szymanski for the ALICE collaboration
a University of Bratislava, Bratislava, Slovakia bCERN, Geneva, Switzerland c University of Frankfurt, Frankfurt, Germany
A proportional chamber with ring cathode readout is foreseen for the ALICE Time Projection Chamber. It offers low gas gain operation, light-weight construction and good pulse shape. The Tape Automatic Bonding (TAB) process makes it possible to mount the VLSI analog front end electronics directly on the back face of the multilayer board carrying the ring cathode elements, yielding high channel density. At the same time, simulation work is done. Construction and first results will be presented.
39 AT9900142
Thursday 26 February
The First Low Mass Radial TPC: The NA45-CERES Thul8.10| Upgrade
A. Sharma, for the Ceres Collaboration
GSI, Darmstadt, Germany
The NA45/CERES experiment at CERN is being upgraded for significantly im- proving the dilepton mass resolution to permit momentum resolution to be a few MeV/c2. This is concieved by the addition of a low mass radial TPC. which will be described in this contribution, immediately after the existing spectrometer. Ex- tensive design and experimental prototype studies will be reported both in terms of reduction of material for the polymer foil field cage which hosts the voltage di- vider from a high voltage of 50 kV on the inner cylinder to the readout chambers arranged modularly on the outer cylinder, and its high voltage performance. Simu- lations have been performed to evaluate the distortions in the radial drift field due to the various parameters involved, namely discrete strips and resistor tolerances and the drift volume has been optimized accordingly. The gas mixture has been chosen vis-a-vis low mass and performance and is a (90-10) mixture of Ne-CO2 with a maximum drift time of 60 mus.
40 AT9900143
27 February Friday
Muon Detection at Hadron Colliders
G. Mitselmakher
University of Florida, Florida, USA & Fermilab, Batavia, IL, USA
The development of Muon detectors proposed for the upgraded CDF and DO ex- periments at Tevatron as well as CMS and ATLAS at LHC is reviewed. The results of recent R&D on the detectors and associated muon triggering problems are pre- sented.
41 AT9900144
Friday 27 February
The Barrel Muon Chamber of the CMS experiment: Fri 9.50 I recent results
E. Torassad Representing the CMS Barrel Muon Collaboration *AACHEN-3A, RWTH, III. Physik. Inst. , Aachen, Germany bUniv. di Bologna e Sez. dell' INFN, Bologna, Italy CCIEMAT, Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Madrid, Spain dUniv. di Padova e Sez. dell' INFN, Padova, Italy eUniv. di Torino e Sez. dell' INFN, Torino, Italy
The barrel muon chambers of the CMS experiment are made assembling 3 SuperLay- ers giving
42 AT9900145
27 February Friday
The Precision Drift Chambers for the ATLAS Muon Pri 10.15 I Spectrometer
N. Hessey on behalf of the ATLAS Muon Collaboration
Universitat Munchen, Munich, Germany
The ATLAS Muon Spectrometer will use drift tubes for precise measurement of muon tracks in the toroidal magnetic field. The physics goals require a precision on the sagitta measurement of 50 fim. The planned operating conditions will be discussed, including signal conditioning and choice of gas for the high rate LHC environment. Recent measurements of the performance will be presented.
43 AT9900146
Friday 27 February
Results from a full scale prototype of the ATLAS MDT muon chamber
P. Bagnaiaa, L. Pontecorvoa and M. Cambiaghib
'•Universitd La Sapienza and INFNROMA, Roma, Italy b Universita' di Pavia and INFN Pavia, Pavia, Italy
On the framework of the ATLAS MUON GROUP activities we have built and tested a full scale prototype of the Barrel Inner Large (BIL) Chambers. The chamber is 100 x 260cm2, with 192 tubes arranged in 2 multilayer of three layers each. The tubes are operated at 3 Bar absolute pressure at a gain of 2xl04 in proportional mode. The gas mixture used is 91% Ar, 4% N2 and 5% CH4. We present results both on the mechanical construction accuracy and on the drift and tracking properties of the tubes. The wire positions were measured using both an X-ray tomograph and muon tracks from the H8 beam line at CERN. The measured position agreed with the nominal one within 20/j.m. The measured single wire resolution is about 80/im; the tracking angular resolution of the chamber is less than .5mrad. The result on the wire resolution as a function of the drift distance compares very well with an accurate GARFIELD model of the tube and related electronics. We also present a very accurate automatic procedure to find the TO of each wire (< .5ns precision), and an autocalibration procedures that measures the effective R-T relation with an accuracy of better than 20yum.
44 AT9900147
27 February Friday
High-precision X-ray Tomograph for quality control of Fri 11.55 I the ATLAS muon Monitored Drift Chambers
E. Gschwendtner. J.-M. Maugain, F. Rohrbach and Y. Sedykh
CERN-EP, Geneva, Switzerland
For the Large Hadron Collider (LHC), a large general-purpose experiment, the AT- LAS project, is being constructed. One of its sub-detector, the MDT project, has the scale of a very large industrial project: twelve hundred large muon drift chambers will be built aiming at an exceptional quality in term of mechanical accuracy, mate- rial reliability, assembly and monitoring.The mechanical quality control is based on the use of X-ray tomography. An X-ray Tomograph prototype, monitored by a set of interferometers, has been developed and built at CERN to provide an accuracy of about ten micrometers in the determination of the position of each individual drift tube of the MDT chambers. Results have been obtained on MDT prototypes: they show the validity of the X-ray tomograph approach.
45 AT9900148
Friday 27 February
An 8 m2 cylindrical tracking detector made of 2.5 m Fri 12.20 | long, stereo mylar straw tubes with 100 fim resolution: commissioning and performances
L. Benussia, M. Bertania, S. Biancoa. F.L. Fabbria, P. Gianottia, M. Giardonia, C. Guaraldoa, A. Lanaroa, J. Lub. V. Lucherinia, A. Mecozzia, L. Passamontia, V. Russoa, S. Sarwara, V. Serdyouka A. Volkova and A. Ziac
*Laboratori Nazionali di Frascati, I-OOO44 Frascati, Italy. bon leave from Hebei University, Poeple's Republic of China. con leave from Pakistan Atomic Energy Commission.
An array of 2424 2.5 m-long, 15 mm-diameter mylar straw tubes, arranged in two axial and four stereo layers, has been assembled: The array covers a cylindrical tracking surface of 8 m2 and provides coordinate measurement in the drift direction and along the wire. A novel procedure was invented to correct severe systematic effects introduced by gravitational sag and straw electrostatics, which dominate the detector performance specially with straws of large length. The algorithm allows to determine wire position from drift-time distribution and has been successfully ap- plied to reach a space resolution of 40 nm with DME, and 100 nm with Ar+C2H6, for 2.5 m long straws with a 15 mm diameter. Such a resolution is the best ever ob- tained for straws of these dimensions. The array is being commissioned and tracking performances as obtained from cosmic ray tests are discussed.
46 AT9900149
27 February Friday
Recent Developments in Pattern Recognition Fri 14.00 | with Applications in High Energy Physics IT
H. Bischof
Pattern Recognition and Image Processing Group, Vienna University of Technology, Vienna, Austria
In this contribution we consider the track finding and fitting problem from the pattern recognition and computer vision point of view. In particular, we consider it as a problem of recovering parametric models from noisy measurements. We review major approaches like neural networks, hough transforms, Kalman filtering techniques, etc, which have been previously used in that area, and point out the problems of these approaches. Then we present an algorithm, originally developed in the area of computer vision, to fit different types of curves to noisy edge data, and demonstrate how it can be used for track finding and fitting. The algorithm is based on two principles: a) A data driven exploration produces many hypotheses of possible tracks, b) A selection procedure based on the Minimum Description Length Principle (MDL), selects those hypotheses which are needed to explain the data. The results of the algorithm are a number of tracks, and a set of outlier points (which can not be explained by tracks according to the MDL-principle). We discuss how knowledge about the detectors and the underlying processes can be incorporated in the algorithm. Finally, we demonstrate that this algorithm has various advantages over other methods, is robust, and produces highly accurate results.
47 AT9900150
Friday 27 February
Composite photocathodes for visible photon imaging Fri 14.50 I with gaseous photomultipliers
E. Shefera, A. Breskina, R. Chechika, A. Buzulutskovb and M. Pragerc
AWeizmann Institute of Science, Rehovot, Israel bBINP, Novosibirsk. Russia CELAM Ltd., Jerusalem. Israel
We demonstrate that coating alkali-antimonide photocathodes for visible light with a thin alkali-halide film can protect the photocathode form contact with gas impuri- ties, at the cost of a reduced quantum efficiency. We report on the results of coating Cs3Sb and K-Cs-Sb photocathodes with Nal, Csl and CsBr films. Photoelectron transport through the coating film, absolute quantum efficiency and the effect of exposure to oxygen and to dry air are presented. Our best results in terms of quan- tum efficiency and stability were achieved with K-Cs-Sb photocathodes coated with 300A thick CsBr and 250A thick Csl films. These photocathodes have quantum ef- ficiency > 5% and ~ 4% at 300-350nm and 275-325nm spectral range respectively. They can withstand exposure to considerable doses of oxygen and dry air. Their be- havior under intense photon flux is presented. Suitable gaseous electron multipliers and possible applications are discussed.
48 AT9900151
27 February Friday
Test Beam Results from the CLEO III LiF-TEA Ring Imaging Cherenkov Detector
M. Artusoa, F. Azfara, A. Efimova, S. Koppa, R. Mountain3, S. Schuha, T. Skwarnickia, S. Stone a, G. Viehhausera. T. Coanb, V. Fadeyevb, I. Volobouevb, J. Yeb, S. Anderson0, A. Smith0. Y. Kubota0 and E. Lipelessd
^Syracuse University, USA ^Southern Methodist University, USA c University of Minnesota, USA d California Institute of Technology, USA
We report on a test beam run of CLEO III RICH modules. The system consists of LiF radiators and multiwire proportional chambers containing a mixture of CH4 and TEA gases. The radiators were both flat and "sawtooth". The data were taken in a beam dump at Fermilab. We will discuss the chamber stability, electronics, the number of photons observed for both radiators, the angular resolution per photon and the angular resolution per track.
49 AT9900152
Friday 27 February
Results from the E835 Scintillating Fiber Detector Fri 16.30 "
M. Ambrogiani, W. Baldini, D. Bettoni, M. Bombonati, D. Bonsi, R. Calabrese. E. Luppi, R. Mussa and G. Stancari
University of Ferrara and I.N.F.N., Ferrara. Italy
A cylindrical scintillating fiber tracker for the measurement of the polar coordinate 9 has been built for experiment E835 at Fermilab. This detector combines the high- granularity, flexibility and fast response of the scintillating fibers with the high quantum efficiency of the Visible-Light Photon Counters (VLPC). This is the first detector used in a High-Energy Physics experiment which exploits scintillating fibers and VLPC's. The detector has been used for the measurement of the polar angle 9 (with respect to the beam direction), as well as for the discrimination between mips and electron- positron pairs from photon conversions. The prompt signals from the detector were exploited to provide a first level trigger. Complete results about the tracker performance are given: tracking and timing resolution, photoelectron yield per mip, detection efficiency, single-double track dis- crimination.
50 AT9900153
27 February Friday-
Aerogel Cherenkov counters with wavelength shifters and phototubes
A. Onuchin
Budker Institute of Nuclear Physics, Novosibirsk, Russia
The work is devoted to the development of Cherenkov counters based on the Aero- gel, wavelength SHIfters and PHototubes (ASHIPH). As compared to the option of the direct light collection on the photomultiplier (PMT). this method gives a possibility to diminish the number of PMTs essentially. The coefficient of the trans- formation of a photon to a photoelectron in the WLS was measured. Series of new shifters were developed. The absorption and the scattering lengths in the aerogel were measured. The reflection coefficient for the PTFE film and the Millipore paper were measured. The Monte Carlo simulation code was developed to determine the number of photoelectrons in the ASHIPH. A counter based on KN-18 WLS and one 2" FM PMT from Hamamatsu was developed. Sizes of the counter are 35 by 25 cm. The counter prototype was tested at the T10 beam at CERN. The MC calculation and the experiment are in agreement. Counters based on two types of shifters, blue and green, and the PMT with a multialcali photocathode are developed. The MCP PMT (MicroChannel Plate PMT) with the multialcali photocathode produced by "Ecran" plant (Novosibirsk) was used.
51 AT9900154
Friday 27 February
Performance of the KTeV Transition Radiation Fri 17.20 I Detector System
N. Solomey for the KTeV Collaboration
Enrico Fermi Institute, The University of Chicago, USA
A large area, nine chamber transition radiation detector system was designed and constructed for the KTeV rare Kaon decay experiment E799 of Fermilab. The de- velopment and performance of this particle identification detector system will be presented. The design goal of this system was to be better than 100:1 pion/electron rejection at 90 % electron efficiency; however, the system performed better achiev- ing nearly 300:1 rejection. Although this system was a gaseous detector with slow charge collection it was still able to be used effectively in a fast experiment.
52 Poster
53 AT9900155
Poster
Construction of the CLEOIII Drift Chamber A2 I
M. Dickson
Cornell University, Ithaca, New York, U.S.A.
The construction of the CLEOIII drift chamber is currently underway. Manufactur- ing, assembly and surveying of the endplates has been completed and stringing of the chamber is ready to commence. Particular care has been placed on maintaining the accuracy of the wire positions through the entire life-cycle of the chamber. In this talk, after briefly describing the design goals of the drift chamber, the methods used and the accuracies attained in its construction be will discussed. Particular emphasis will be placed on the steps taken to understand and minimize the role wire creep will play in the future of the chamber.
54 AT9900156
Poster A
The Performance of Drift Chamber of the CMD-2 A3 I Detector.
D.V. Chernyak, D. Gorbachev. F.V. Ignatov, B.I. Khazin, P.A. Lukin, A.S. Popov, A. Ruban, A.L. Sibidanov, I.G. Snopkov and E.P. Solodov
Budker Institute of Nuclear Physics, Novosibirsk, Russia
The CMD-2 Detector is running on the electron-positron collider VEPP-2M at Novosibirsk since 1992. The cylindrical drift chamber of the detector and two lay- ers of multiwire proportional chamber with strip cathodes, allowing the precise measurtement of coordinate along the beam (Z-chamber), are placed inside of the superconducting solenoid with a magnetic field of 10 kGs parallel to the chambers axis. The outer radius of the drift chamber and its length are equal to 30 cm and 44 cm correspondingly. The working gas mixture is Argon - isobutane (80/20). The chamber sense wires are organized in three superlayers of jet-like cells with a total number of samples along the radial track being equal to 19. Z-coordinate in DC is measured by charge division. The special procedure of electronical calibration of individual channels delay time and transmission parameters ensures proper time and Z-coordinate measurements. While the resolution inside one cell is about 150 /xm, the problem of matching together track fragments belonging to different cells still exists - the drift coordinate resolution all over the track is not better than 240 fira. The efficiency of track reconstruction in DC is better than 98% for particles with momenta greater than 100 MeV/c. Further improvement of Z-coordinate evaluation were achieved after calibration of DC with a help of hits with precisely measzured coordinates in the Z-chamber. Finally the resolution of the DC along Z is at the level of 1% with a systematic error below 0.1%. The collected through these years experience regarding the influence of physical pro- cesses in gas mixture and electronic calibrations on precision drift and Z-coordinates measurement as well as dB/dx accuracy are discussed.
55 AT9900157
Poster
Results from the Muon Tracking Detector in the air-shower experiment KASCADE
I. Atanasovd, W. Bartlc, K. Daumillerb, P. Dolla, B. Hoffmanna, H. Kerna, b a d b a K.H. Kampert , H.O. Klages , L. Pentchev : F.K. Schmidt , G. Rabsch , G. Schleifa, R. Wegstb and J. Zabierowski1 e
^Research Center Karslruke, Karlsruhe,Germany b University of Karlsruhe, Karlsruhe, Germany cInstitut fur Hochenergiephysik, Vienna, Austria d Institute of Nuclear Research, Sofia, Bulgaria eSoltan Institute for Nuclear Studies, Lodz, Poland
A large area Streamer Tube (ST) detector, located within the KASCADE experi- ment, is presently being built with the aim to identify muons from Extensive Air Showers (EAS) by track measurements under more than 18r.l. shielding. Together with the company WATECH 1000 ST detectors of 4m length have been built and tested. Extensive tests led to many improvements in the detector construction. The profiles were produced using conductive PVC of high quality (10°Ohm/cm2) and the cover of the profile was made out of bakalite (1011 Ohm/cm2), which helps to close the field effectively around the anode wire. Novel and economic techniques have also been developed to produce large area pick-up electrodes. Test results demonstrate the unique properties of these ST detectors. They are arranged in 3 horizontal planes on a base line of 48m as a telescope, to determine the angles of the muons, which are grouped around the EAS axis, being determined by the KASCADE scintillator array. In total about 500m2*sr will be instrumented which allow to investigate, together with the array and the hadron calorimeter, the nature of high energy cosmic ray particles in the energy range around 1015 eV.
1) supported in part by the Polish State Committee for Scientific Research (KBN grant 2P03B16012)
56 AT9900158
Poster A
MTF and DQE measurements in imaging detectors by A 5 I their single-event response
P. Ottonelloa, G.A. Rottignia, C. Sartorib, G. Zanella* and R. Zannonia
"•Dipartimento di Fisica dell'Universita'di Genova and Institute Nazionale di Fisica Nucleare, Sezione di Genova. Genova. Italy bDipartimento di Fisica dell'Universita'di Padova and Instituto Nazionale di Fisica Nucleare, Sezione di Padova. Padova, Italy
Radiation imaging is an intricate process which requires summation, on each pixel of the image, of all single-event responses detected in the same time interval. This process furnishes, in general, a multi-bit two-dimensional spatial function, where (if the system is linear) the bits do not represent exactly grey levels, also in the case of a noiseless detector.This is due to the statistical nature of the radiation which fluctuates, at the detector input, following practically the Poisson statistics. Other noises appear in the imaging process, these are: the fluctuation due to a quantum efficiency (QE) smaller than one, the cluster fluctuation [1] due to the statistics in- volved in the final avalanche produced by each detected radiation quantum and the ambient noise due to various sources (dark current noise, readout noise, digitisation noise, etc.). Imaging detectors based on localisation and counting, in real time, of the detected single-events do not introduce the cluster noise, which is typical of integrating imaging detectors. Therefore, a completely noiseless imaging detector requires QE=1, and for this reason a detector with QE j 1 is named quasi-ideal de- tector, if other noise sources are missing [2]. The noise introduced by a real detector reduces its efficiency to an equivalent value called DQE (detective quantum effi- cieny), where a quasi-ideal detector has DQE=QE. On the contrary of QE, DQE is dependent on: the input signal, the cluster noise, the ambient noise and the spatial resolution (MTF) of the detector. After a theoretical introduction on this concepts, we shall see as the MFT of the system and the cluster noise can be measured by the analysis of the single-event pulse distribution, intending the single-event response as the impulse response of the system. Experimental results are showed using a CCD-based scintillation X-ray area detector and X-rays in the 8keV - 45keV energy range.
57 AT9900159
Poster
Studies on ageing effect and rate dependence A 6 I of Thin Gap Chambers
H. Fukuia. M. Yoshidab, Y. Miyazaki0, Y. Fukatsub, Y. Hasegawab, T. Hosoda0, M. Ikenod, T. Ishidaa, H. Iwasakid, 0. Jinnouchib, T. Kobayashib, T. Kusanoa, G. Mikenberg6, M. Nozakia, T. K. Ohskad, T. Takeshita0 and K. Yamauchid
aKobe University, Faculty of Science, Japan b University of Tokyo, International Center for Elementary Particle Physics (ICEPP), Japan cShinshu University, Faculty of Science, Japan dHigh Energy Accelerator Research Organization (KEK), Japan e Weizmann Institute of Science, Rehovot, Israel
We studied ageing effect of the Thin Gap Chamber (TGC). The chamber paramters are 2.0mm in wire spacing and 1.6mm in the anode-cathode gap. The wire is gold- plated tungsten of 50^m in diameter and cathode is made of graphite. The gas mixture used is 55% of CO2 and 45% of n-pentane. The TGCs were irradiated with /3-rays of 90Sr source and the maximum hit rate was 80kHz/cm per wire. The gas flow rate was 5~40cc/min. which corresponds to 0.3~2.6 replacements of the TGC volume per minute. We observed no significant deterioration on the pulse height and the time jitter up to accumulated charge of lC/cm. We also performed a beam test to study the TGC performance under high radiation environment. The background rate of approximately 3MHz/cm2 was overlaid on the beam with using 90Sr source. The cathode area of the TGC was 6cm x 8cm. The pulse height did not significantly change up to 100kHz/cm2.
58 AT9900160
Poster A
Effective Secondary Emission Emitters for Secondary A 7 I Emission Detectors
V.G. Gavalian and M.P. Lorikian
Yerevan Physics Institute, Yerevan, Armenia
The phenomena of the induced secondary electron emission (SEE) radiation from different materials is widely used in the particle detectors. Among the emitters of the secondary electrons, the most effective are the dielectrics made of alkali-halides and oxides of some metals. In this works a new emitters of secondary electron emission was suggested in which the electric field E = 104 -=-105 V/cm was imposed on the dielectric layer by the potential applied to the substratum of the layer and to special mesh, pressed to the other side of the layer. This method allows to increase essentially the mean yield of the emitted secondary electrons (up to the 500) under the irradiation by the 1 -r 2 MeV electrons and in case of irradiation by a-particles (up to few thou- sands). Multiplication of electrons in porous dielectric goes in the same way as it is in the gas. The mean yield of secondary electrons being controlled by external electric field. This phenomena was called as controlled secondary electron emission (CSEE). Effective emitters of secondary electrons from the porous dielectrics KCL, MgO, Csl, KBr, LiF, NasAlF6 (creolit), with the relative density 1 -r 2 % and of 50 -T- 400 jxm thickness were made using this method. The statistical distribution of the number of emitted electrons and volt-emission characteristics of some of these emitters (dependence of the average secondary emission coefficient on the electric field strength E) presented. On the basis of these emitters a series of new radiation detectors allowing an ~ 80-^-100% efficiency to register both strongly and minimally ionizing charged particles as well as X-rays with time and spatial resolution ~ lOOps and ~ lOOmum respectively have been developed and constructed. The detectors operated in vacuum-tight vessel at continuous evacuation, the vacuum being better than 10~2 Torr.
59 AT9900161
Poster
Studies of an MSGC equipped with a GEM grid A 8 I as a tracking device
W. Beaumonta, T. Beckersa. 0. Bouhalib, J. De Troya, C. Vander Veldeb, b a b b W. Van Doninck , C. Van Dyck ; P. Vanlaer , F. Verbeure% F. Udo and V. Zhukovb
aC//A, Antwerp, Belgium bIIHE ULB/VUB, Brussels, Belgium
The performance of a Micro Strip Gas Counter (MSGC) has been studied in con- junction with a Gas Electron Multiplier (GEM). Tests have been performed in a cosmic hodoscope on a 100 * 100mm2 MSGC, equipped with a GEM grid, to study spatial resolution and efficiency.We have in- vestigated the performance of this detector for different DMEbased gas mixtures.In a Ne/DME mixture (1/2), at an amplification of ~5 for the GEM and ~300 for the MSGC the spatial resolution and minimum ionizing particle detection efficiency are similar to the ones obtainedwith a bare MSGC operated at a gain ~1500. Tests are under way with a pulsed focused nitrogen laser.With this setup, we will be able to optimize the operating voltages andgas mixture for use as a tracking detector. These measurements will lead to a review of the possibilities to use a GEM/MSGC combination in tracking applications.
60 AT9900162
Poster A
High pressure operation of the Gas Electron A 9 I Multiplier in Ar- and Xe-based gas mixtures
A. Buzulutskov and L. Shekhtman
Budker Institute of Nuclear Physics, Novosibirsk, Russia
Application of the Gas Micro-Strip Chambers (MSGCs) in X-ray digital radiog- raphy and in synchrotron radiation devices require their operation in pressurised Xe-based gas mixtures. However, this possibility is limited due to the reduction of the maximum safe gain of MSGCs observed at high pressures. Adding of the Gas Electron Multiplier (GEM) as a pre-amplification element to the pressurised MSGC could solve this problem. In this study we present data on GEM operation in gas mixtures Ar-CO2 and Xe-CO2 at 1, 3 and 5 atm. We have measured the amplification factor of GEM itself and in combination with MSGC at different CO2 concentrations.
61 AT9900163
Poster
Development of a low-mass drift chamber system for the HADES di-electron spectrometer
J. Stroth.al K. Bethgea, H. Bokemeyerc, S.P. Chernenko", O.V. Fateevb, J.M. Garabatos*, L. Glonti\ W. Kariga, W. Koenigc, C. Muntza, L. Smykovb, A. Steigerwalda, H. Stelzer0, J. Wiistenfeld", Yu. V. Zanewskyb, A. Zenteka and P. Zumbruch0
*Johann Wolfgang Goethe-Universitdt, Frankfurt, Germany b Joint Institute of Nuclear Research(JINR), Dubna, Russia c Gesellschaft fur Schwerionenforschung (GSI), Darmstadt, Germany
A new high resolution (AM/M < 1 %) and high acceptance (45 %) di-electron spectrometer (HADES) has been designed to investigate in-medium properties of hadrons. For tracking of all charged particles (in particular with sufficient resolution for electrons) a system of 24 low-mass drift chambers (Helium based counting gas and Aluminium field and cathode wires), arranged in four tracking planes, will be used. This contribution will flash design aspects of the chambers and the read- out concept for the tracking system. The outcome of two years of performance optimisation using various prototype detectors will be reported, including results of an ageing test. We observe stable operation in the high-multiplicity environment of heavy ion collisions, and a spatial resolution of 70 /j.m(a) over 80 % of a cell.
1 corresponding author, [email protected]
62 AT9900164
Poster A
Ageing studies for the ATLAS monitored drift tubes A 11 I WCC 1998
M. Kollefrath a, V. Paschhoffa. M. Spegela, U. Topp a, C. Fabjana, G.Hertena, U. Landgrafa, W.Mohraand M.Treichela.
^Fakultat fur Physik, Universitdt Freiburg, Germany bCERN, Geneva. Switzerland
The drift tubes of the ATLAS muon spectrometer are expected to accumulate up to 0.6 C/cm wire during 10 years of operation. We present results from lifetime tests at Freiburg and CERN with four gas mixtures. The influence of the cathode was investigated using various coatings for the aluminium tubes. The rate dependence of ageing was studied in order to extrapolate from accelerated tests to real ATLAS conditions. We investigated the impact of different gas flows and outgassing from end plug materials. Water and ethanol were tested as a remedy against ageing. A technique to reactivate inefficient tubes was developed. Additional high statistics tests (192 tubes) are performed to confirm the results from the single tubes.
63 AT9900165
Poster
Sector Multipad Prototype of the FMD-MCP A 12 I Detector for ALICE
A.E. Antropov0, A.V. Fedotovb, G.A. Feofilovc, E.K. Izrailovd, b a c e c V.A. Kasatkin , W. Klempt , A.A. Kolojvari , M.P. Larin ; V. Lazarev ; d d c 0 LA. Novikov , S.V. Potapov , O.I. Stolyarov : F.A. Tsimbal , c 0 c T.A. Tulina : F.F. Valiev , L.I. Vinogradov for the ALICE collaboration *-CERN, Geneva, Switzerland bGranit Sci. Res. Inst., St. Petersburg, Russia cSt. Petersburg University, St. Petersburg, Russia d VNIIM, St. Petersburg, Russia eAnalitpribor Sci. Res. Inst., St. Petersburg, Russia
We present results of the technology, manufacturing and first tests of a novel MCP- based sector prototype for the Forward Multiplicity Detector for the ALICE ex- periment at the LHC. The detector is to provide better than i/(M)/M resolution for high multiplicity events, and about 50 ps timing resolution. Two Sector MCPs are mounted on a 200 fj,m ceramics board with the multipad readout integrated with a passive Summator. This microelectronics UHF device provides isochronous analogue summation of the fast Ins signal components from 8 pads along with the individual readout of charges. The setup is baked under 300°C and then sealed into a singular thin wall (200 (im) stainless steel vacuum sector chamber with Ti getter keeping a vacuum of 10~5Torr. The separation of the fast and slow components allows us to use this detector as the zero level trigger, in pile up and beam-gas interaction diagnostics and for the determination of the collision vertex along the beam axis. The results of the first and future lab and in-beam tests are discussed and presented.
64 11111111111 AT9900166
Poster
First System Performance Experience with the ATLAS High Precision Muon Drift Tube Chambers
P. Hendriksa, M. Woudstraa, F. Lindea, G. Stavropoulosa. M. Vreeswijk a andH. Dietlc
*NIKHEF Amsterdam, Netherland bCERN, 1211 Geneva 23, Switzerland CMPI Munich, Germany
Three prototype monitored drift tube (MDT) chambers corresponding to a full size ATLAS barrel section have been tested in the cosmic ray test setup DATCHA at CERN. First experiences with the operation of the MDT chambers axe discussed. The event reconstruction is based on a procedure which allows to self calibrate the distance-time relation with high precision by using tracks. Results on the recon- struction of the events, which invokes the in-plane and projective alignment system, demonstrate that an accurate chamber alignment as required in the ATLAS detector can be achieved.
65 AT9900167
Poster
Design, characterization and beam test performance of A 14 I different silicon microstrip detector geometries
E. Catacchini, L. Ciampolini, C. Civinini, R. D'Alessandro. E. Focardi. M. Lenzi, M. Meschini, G. Parrini and M. Pieri
INFN-Firenze and Universita di Firenze, Florence, Italy
During the last few years a large number of Silicon Microstrip Detectors have been especially designed and tested in order to study and optimize the performances of the tracking devices to be used in the forward-backward part of the CMS experiment. Both single and double sided silicon detectors of trapezoidal ("Wedge") shape and with different strips configuration, including prototypes produced with double metal technology, have been characterized in laboratory and tested using high energy beams. Furthermore, due to the high radiation environment where the detectors should operate, particular care has been devoted to the study of the characteristics of heavily irradiated detectors. The main results on detector performances (charge response, signal to noise ratio, spatial resolution etc.) will be reviewed and discussed.
66 AT9900168 Poster A
Si, GaAs and diamond damage in pion fields, with A 15 I application to LHC
S. Lazanua and I. Lazanub
^National Institute of Materials Physics, Bucharest-Magurele, Romania b University of Bucharest, Bucharest-Magurele, Romania
A very important problem related to the use of semiconductor materials for devices in hostile radiation environments is their damage in the fields where they have to work. For the new generation of colliders, the most abundant produced particles are the charged pions, with an energetic spectrum up to tens of GeV. The non-ionising energy loss (NIEL) and the concentration of primary radiation defects induced by charged pions, in the energy range 50 MeV-50 GeV, in the bulk of silicon, GaAs and diamond have been calculated in order to characterise the radiation resistance of these materials. The mechanisms by which the pion imparts energy to the lattice have been analysed and their contribution has been evaluated starting from the data on pion - nucleus interaction. The energy partition of the primary recoil nuclei between ionisation and displacements has been considered in the frame of the Lind- hard theory. The energy dependence of both NIEL and concentration of induced primary defects presents two maxima, the relative importance of which depends on the target mass number: one in the region of the delta resonance, and another one around 1 GeV. The main result is that diamond is hardner to pion irradiation that both silicon and GaAs in the whole energy range investigated. These results are discussed in the context of the simulated spectra for charged pions in the inner detector system at LHC.
67 AT9900169
Poster
The SHOWER detector readout system in HADES experiment at GSI Darmstadt
P. Salaburaa, M. Kajetanowicb. L. Kidona, K. Korcylb, W. Kuehnc, c a b a M. Petri : J. Pietraszko , A. Skoczen and E. Wajda for the HADES collaboration
^Institute of Physics Jagellonian University, Krakow. Poland ^Nowoczesna Elektronika, Krakow, Poland cJustus-Liebig-Universitaet Giessen, Germany
HADES (A High Acceptance Dielectron Spectrometer) is a second generation ex- periment being under construction at Geselschaft fuer Schwerionenforschung (GSI) heavy ion synchrotron facility in Darmstadt (Germany). HADES scientific program includes studies of in-medium properties of hadrons in hot and dense hadronic mat- ter and its electromagnetic structure. The SHOWER detector is a section of the HADES spectrometer designed for second electron identification and event char- acterization. It is built of wire chambers working in self-quenching streamer mode (SQS) with pad-readout. The poster presents the SHOWER readout system. The charge collected from the detector is integrated and shaped in newly developed analog ASICs, digitized and transmitted via optical link to the specially designed Pattern Recognition Unit. The total multiplexing ratio of 3072:1 is planned. The multiplexing ratio 768:1 is implemented. The transmitted data ratio is 105 events/s or 1.9Gb/s over a distance of ~100m. The presented prototype has ben tested and achieved the full expected performance and functionality. AT9900170
Poster A
Data Compressio/Decompression System and Pattern A 17 I Comparator ASIC for the CMS RPC Muon Trigger
M. Gorskia, Z. Jaworski0,1.M. Kudlab. K.T. Pozniakc, W. Kuzmicz0 and M. Niewczas0
*Soltan Institute of Nuclear Studies, Warsaw, Poland b Warsaw University of Technology, Warsaw, Poland c Warsaw University, Warsaw, Poland
The CMS detector will have a dedicated subdetector (RPC chambers) to identify muons, measure their transverse momenta pt, and determine the bunch crossings from which they originate. Trigger algorithm is based on muon track search and classification in raw data from the RPC chambers grouped in the four muon stations in the CMS magnet yoke. A huge interconnection network is needed to fulfill this task. It can be built in the control room only, approximately 120 m away from the detector. 1. The data compression/decompression system is proposed to reduce the number of links needed to transfer the data from detector to control room. The idea of such a system and results of first tests will be presented. 2. The Pattern Comparator (PAC) ASIC will search for tracks of muons and measure their momenta. The idea of PAC and its first prototype implementation will be shown.
69 AT9900171
Poster
Test of a wire 3He gaz position sensitive neutron detector based on a delay line technology
M. Antoniadesa, H. Challan-Belvala, M. Donois3. G. Koskasa, A. Menelle8 G, Pepya and A. Gabrielb
&Laboratoire Lon Brillouin, CEA SAclay, Gif sur Yvette Cedex, France bEMBL, Avenue des Martyrs, BP 156, Grenoble Cedex, France
A new type of neutron wire detector, filled with 3He gaz, has been derived at the EMBL Grenoble outstation from well known X-ray detectors. These detectors use a delay line technology in order to build a time transfer difference in order to de- fine the neutron detection position. The main electronic parts are built in current preamplifiers and a specific time digital converter. The other electronic parts are standard. The tests were performed on the LLB G5-6 and EROS neutron spec- trometers. They included observations about linearity of the position acquisition, efficiency, background, stability, reliability. The problems of background and thresh- old and high voltage adjustments will be discussed.
70 AT9900172
Poster A
High Speed PC-based Parallel Delay Line Readout A 19
H. Mioa, M. ChemlouP, P. Laggnera, M.H.J. Kochb, A. Gabriel0, C. de Raad Iselid, F. Krummenacherd and W. Leingartnere
"•Institute for Biophysics and X-Ray Structure Research of the Austrian Academy of Science, Graz, Austria bEuropean Molecular Biology Laboratory, Hamburg Outstation EMBL c/o DESY, Hamburg, Germany cEuropean Molecular Biology Laboratory, Grenoble Outstation EMBL c/o ILL, Grenoble Cedex 9, France d Smart Silicon Systems, Lausanne, Switzerland eHECUSM. BRAUN-GRAZ GmbH., Graz, Austria
The design and performance of a new PC-based readout system for linear posi- tion sensitive X-ray detectors, operating as an on-line time correlator based on space-time-space conversion relying essentially two back to back delay lines, will be described. The time correlation method, which was realised in an ASIC (Applica- tion Specific Integrated Circuit), offers the advantage that even coincident pulses within a limit of 5 ns can be processed and no extra rejection is needed. Further- more the count rate of the method is only limited by the minimum pulse width of 10 ns of the input signal. Therefore count rates up to 50 MHz can be achieved. The results of comparative tests with the same detector, using a 3 MHz Time-to-Digital Converter (TDC) with associated histogramming data acquisition system, carried out on a rotating anode and on a synchrotron radiation source will be presented.
71 AT9900173 Poster
Fast gas ionization calorimeters filled with C3F8 gas for operation at high counting rate conditions
N. Fedyakin for the IHEP group
Institute for High Energy Physics, Protvino. Russia
The performance of two gas ionization calorimeters with planar electrodes and steel absorbers has been studied in electron and hadron beams. Both calorimeters are optimized for operation at high counting rate conditions by minimizing inductance of readout cell and choosing of very fast heavy gas C3F8. This gas has been used for the first time in the calorimetry applications. The signals in the large 215 chan- nel hadron calorimeter are readout via a transmission line by remote low noise 50 Ohm preamplifier. Another small electromagnetic calorimeter exhibits a 25 ohm characteristic impedance of a distributed LC chain formed by electrodes and for the sake of matching we have used 25 Ohm transmission line , terminated by the 25 ohm low-noise preamplifier. The dependencies of the calorimeter responses and the resolution on a pressure and HV are presented.
72 AT9900174
Poster A
Manufacturing and Studies of Tile/Fiber Systems in Kharkov (Ukraine) for LHC Calorimetry
A. Nemashkaloa, V. Popova, A. Rubashkina, P. Sorokina, A. Zatserklianiya, A. Borisenkob, V. Senchishin0, 0. Skrebtsovc and V. Bolotovd
^National Scientific Center Kharkov Institute of Physics and Technology, Kharkov, Ukraine bKharkov State University, Kharkov, Ukraine ^Kharkov Monocrystal Institute, Kharkov, Ukraine d Institute for Nuclear Research, Moscow, Russia
We present the results from measurements of light output, light yield uniformity, and recovery after radiation damage of tile/fiber systems made from the scintillator produced by injection molding technique in Kharkov. The tiles were trapezoidal in shape, measuring 131x90x122 mm3, with a Kuraray Yll multi-clad WLS read- out. The results are compared with those obtained using the tile/fiber systems manufactured from the Kuraray SCSN-81 scintillator and tested under the same conditions. The light yield uniformity is found to be improved by masking. Effects of milling, polishing, painting of tile edges and mirroring the fiber end were studied.
73 AT9900175
Poster
High Resolution Tracking Detectors Based on Capillaries Filled with Liquid Scintillator and Opto-Electronic Readout
T. Wolffa and the RD46 Collaboration b
a University of Minster, Miinster, Germany bCERN, Geneva, Switzerland
The aim of the Collaboration is to develop high resolution tracking detectors based on thin glass capillary arrays filled with liquid scintillator. This technique pro- vides high hit densities and a position resolution better than 20 //m. The radiation hardness of more than 100 Mrad makes capillary arrays superior to other types of tracking devices with comparable performance. The technique is attractive for inner tracking in collider experiments, microvertex devices, or active targets for short-lived particle detection in high energy physics experiments. High integration levels in the opto-electronic readout based on the use of the Electron Bombarded CCD tubes (EBCCD) and the possibility of optical multiplexing reduces the number of output channels considerably and, thus, the cost of the detector. During 1996 and 1997, two prototype capillary bundles (1.8 m and 0.9 m in length) were in operation. One of them was equipped with a conventional opto-electronic readout chain and the other, for the first time, with a newly developed megapixel EBCCD. Compared to the conventional chains this device has an increased spatial resolution, lower noise and single photo-electron detection capability. The Collaboration also works on the development of thin planar capillary layers, with the aim of adapting capillary detectors to the future collider experiments. Details of the design and performance axe given.
74 AT9900176
Poster A
Anodic alumina oxide microchannel plates A 23
A. Govyadinova, I, Emeliantchikb and A. Kurilinb
^Institute of Electronics, Minsk, Belarus b National Center for Particle and High Energy Physics, Minsk, Belarus
New material for microchannel plates (mcp) is proposed - anodic alumina oxide. MicroChannel plates made of this material potentially can be much cheaper than conventional lead glass mcp. Also significantly smaller channel diameter (up to 70nm) is easily achievable, which means better spatial resolution and possibility to operate in strong magnetic fields. Methods and means are developed for overcoming two main obstacles on the way to anodic alumina oxide mcp - low conductivity of alumina oxide and too large channel length to diameter ratio. Treating alumina oxide with lead allowed to increase conductivity by several orders of magnitude. Directional etching allow to produce etched channels with diameter 2.5/zm and length 65/um. MicroChannel structures with such channels are produced. Electronic microscope photographs of them are taken. On those photographs one can see the spatial structure of channels. Electrical properties of these mcp, treated with lead, were investigated using DC method. Excess of secondary current with respect to input beam current was observed, which can be explained as result of avalanche electron multilication in channels.
75 AT9900177
Poster
Influence of the drift field on avalanche gain and charge collection in microgap detectors at high pressure
F.A.F, Fragaa, R. Ferreira Marquesa, J.R. Gonaloa, A.J.P.L Policarpoa, C.W.E. van Eijkb, R.W. Hollander13, F. van den Bergb and J.A.C. Gonalvesc
'•LIP-Coimbra and Departamento de Fsica da Universidade de Coimbra, Coimbra, Portugal bRadiation Technology Group, IRI, JB Delft, The Netherlands CIPEN and Departamento de Fsica, Pontficia Universidade Catlica, So Paulo, Brasil
One of the main drawbacks of the use of microgap structures when used at high pressure (6 bar) at high count rates ( 10e6 c s-lmm-2) is the limited maximum safe gain at which they can be operated. The use of a pre-amplification device such as the GEM (gas electron multiplier) can obviate to this limitation; however, secondary space charge effects due to charge accumulation at the non metallic surfaces can not be neglected and should be minimized. These positive charge are due to the intrinsic multiplication of the GEM device and to the drift of ions from the anode of the primary detector. We have observed in a previous work that, due to the reduced size of the avalanche at higher pressures, the collection of the positive ions by the drift electrode is of greater value at 6 bar than at atmospheric pressure. In this study we present data on the variation of the positive ion collection by the drift electrode versus drift field at several pressures up to 6 bar using argon, krypton and xenon mixtures. These results are analyzed using simulation tools for computing avalanche development and electrical field configuration.
76 AT9900178
Poster B
Preliminary results with the KEDR drift chamber
S.E. Bam, A.E. Blinov. V.E. Blinov, V.R. Groshev, G.M. Kolachev, V.N. Kozlov, G.D. Minakov. A.P. Onuchin, S.S. Petrosyan, A.V. Rylin, G.A. Savinov. A.G. Shamov. A.I. Shusharo, A.A. Talyshev and A.N. Yushkov
Budker Institute of Nuclear Physics, Novosibirsk, Russia
The 1 m long and 1 m outer diameter drift chamber (DC) of the KEDR detector at the e+e~ collider VEPP-4M (Ejß^ = 6GeV) was built. The chamber wires are arranged in a system of 7 concentric super layers. Four super layers have axial wires while the other three have wires inclined at ±100mrad to the cylinder axis. The chamber operates with a "cool" gas - dimethyl ether (DME) at atmospheric pressure. There are a total of 1512 sense wires and 42 measurements of drift time and dE/dx for tracks traversing the full radial extent of the chamber. For comparision the spatial resolution has been measured in the DC prototype with ^4r/C4Ííio(7O/3O) and DME gas. The best values average over the drift distance of 30mm are equal to 120/um and 40fxm respectively. The value of the gas gain is chosen as a compromise between a spatial resolution which needs a high gain and the dE/dx measurements where a lower gain is preferable.
77 AT9900179
B Poster
Large Cathode Strip Chambers for the CMS Endcap B 2 I Muon System
A. Korytov for the CMS Collaboration
University of Florida, Gainesville, Florida, USA
The CMS Endcap Muon System will consist of 540 6-plane Cathode Strip Chambers, the largest being 3.4 x 1.5 sq. m. in size, with about 0.5 million of readout channels. The total number of wires will exceed 2.5 million. The chambers are required to provide 75 to 150 micron spatial resolution in off-line and about 1 mm resolution in the level 1 trigger. Timing should be good enough to allow for unambiguous assignment of detected muons to corresponding bunch crossings, occurring at LHC every 25 ns. The talk summarizes the results of the three year R&D. The chamber design optimized for the system of this scale and results obtained with prototypes, including large scale ones, are presented in the talk. The performance of prototypes meets the specifications.
78 AT9900180
Poster B
First Results from the Thin Gap Gas Chambers B 3 I Detector Prototype for the DELPHI Endcaps
E. Albrechta, P. Niezurawskia, 0. Ullalanda, P. Adzicb, A. Markoub, F. Fontanellic, V. Graccoc, A. Morellic, P. Morettini0, A. Petroiini0. G. Pianac and M. Pernickad
*CERN, Geneva, Switzerland; bInstitute of Nuclear Physics, N.C.S.R. Demokritos, Athens, Greece cDipartimento di Fisica dell'Universita di Genova and INFN. Genova, Italia dHEPHY, Institut fur Hochenergiephysik, Vienna, Austria
Thin Gap Gas Chambers were proposed for a possible upgrade of the endcaps of the DELPHI detector at LEP. Two full prototypes were built and tested at the CERN 20 GeV/c SPS pion beam. The main construction parameters of the detector and the on-board front-end electronics characteristics are reviewed. Preliminary test beam results from the full prototype, showing the general feasibility of the detector, will be presented.
79 AT9900181
Poster
A Spark-Protected High-Rate Detector B4
P. Fonte, a'b N. Carolinoa, L. Costac, R. Ferreira-Marquesa'd, S. Mendiratta0. V. Peskove and A. Policarpoa'd
aL/P. Dep. de Fisica, Univ. de Coimbra, 3000 Coimbra, Portugal hQuinta da Nora, 3000 Coimbra, Portugal cDepartamento de Fisica, Univ. de Aveiro, 3800 Aveiro, Portugal ^Departamento de Fisica, Univ. de Coimbra, 3000 Coimbra, Portugal eNASA Marshall Space Flight Center, Huntsville, AL 35812, USA
We developed a very low resistivity RPC-type detector, the anode of which was a plate made from materials with resistivity up to 5zlO7 Ohm cm, being the cathode a metallic mesh preceded by a drift region. In such detector it was actually possible to combine the versatility and high counting-rate capability of metallic PPACs with the extreme robustness and "protectiveness" of Resistive Plate Chambers. Occasional discharges triggered by large deposits of primary ionization or by extreme counting rates are quenched by the resistive anode and are constrained to the glow discharge phase of the sparking process. The study shows that this discharge affects the detector only locally and the charge released is limited to a few nC. Proportional counting rates up to 10° Hz/mm2 were achieved at gains above 104. The energy resolution at 6 keV was 20% FWHM. The observed gain-rate trade-off is well described by an analytic model and further improvements may be expected by lowering the resistivity of the anode material. The properties of several custom-made, controllable resistivity, anode materials are described and perspectives of improvement in the performance of the detector are discussed.
80 AT9900182
Poster B
Development of a Straw Tube Chamber with B 5 I Pickup-Pad Readout
C. Leonidopoulos, C. Lu and A. J. Schwartz
Department of Physics, Princeton University, Princeton, NJ, USA
We have developed a straw tube chamber with pickup-pad readout. This technique may have broad application wherever fast, pixel-type information is needed. For the gas avalanche signals to be picked up by the pads, the straw tube material must be highly resistive such that the straw tube wall does not substantially shield signal frequencies. Our final objective is to use such a chamber to trigger on tracks with large trans- verse momentum (pr) in the HERA-B experiment at DESY. To accomplish this we position three chamber stations within the HERA-B spectrometer magnet and input the pad hit pattern to fast coincidence logic. To minimize hit multiplicities and simplify the trigger logic, we have developed a technique limiting the pickup signal to one pad. The pad size can be as small as the diameter of the straw tube, and thus a granularity as small as ~ 4 mm (in the direction transverse to the straw tubes) can be attained in a relatively inexpensive manner. In this paper we describe the construction and performance of two prototype cham- bers. We have tested one of the chambers in a test beam at BNL and have measured chamber efficiencies in excess of 99%. We also present a detailed study of the signal pickup mechanism for this detector system.
81 AT9900183
B Poster
The gaseous detectors for digital scanning radiography B6
S.E. Baru, E.A. Babichev, V.R. Groshev, A.G. Khabakhpashev, V.V. Porosev. G.A. Savinov and V.I. Telnov
Budker Institute of Nuclear Physics, Novosibirsk, Russia
The one-dimensional detectors based on multiwire proportional chamber (MWPC), operating in a direct photon-counting mode and on multichannel ionization chamber are described. The MWPC detector used in our scanning radiographic systems is serially produced. The counting rate of the detector is about 200 MHz, spatial resolution is equal 0.6 mm, the number of channels is 640. The ionization chamber detector has 1024 channels with the strip pitch of 0.4 mm. The gas used is pure Xe at a pressure 11 atm. The comparative characteristics of both type of detectors are presented.
82 AT9900184
Poster B
Irradiation of MSGCs with Low Energy Neutrons
R. Metri, P. Blum, K. Karcher, D. Knoblauch, M. Kraber, Th. Miiller, D. Neuberger, H.J. Simonis and W.H. Thiimmel
Institut fur Experimentelle Kernphysik, Universitat Karlsruhe, Germany
A large part of the inner tracker of CMS will be equipped with Micro Strip Gas Chambers (MSGCs). Besides to a high MlP-rate these detectors also will be exposed to highly ionising particles (HIP), as well as to a considerable flux of low energy neutrons. We have performed experiments with neutrons in the energy range of 0.5—2 MeV, which covers the main part of the neutron spectrum prevailing within the CMS-tracker-volume. Using a time-of-flight method a clear discrimination of the detector response to photons and neutrons has been achieved. The most prob- able neutron energy deposit has been found to be equivalent to 30 MIPs with a conversion probability of e = 10~°. Two MSGCs one based on bare glass and one on diamond-like coated glass, were irradiated with neutrons at high dose (4- W7n/cm2$). After an integral dose equiv- alent to one LHC-year (1 • 1013n/cm2) no indication of severe damage could be found.
83 AT9900185
Poster
Novel large-area, low-pressure MSGCs for thermal B 8 I neutron imaging using composite 157Gd/CsI-convertors
B. Gebauer. Ch. Schulz and Th. Wilpert
Hahn-Meitner-Institut, Berlin, Germany
A novel type of robust, high-gain, large-area MSGCs is presently being developed capable of true two-dimensional single electron imaging; the MSGCs are foreseen for detection of secondary electrons emitted on thermal neutron capture from composite 157 Gd/CsI-convertors. The detectors utilize a novel design, optimized for the low-pressure, high-gain, two-stage amplification mode, elaborated by extensive modeling using the codes MAXWELL (2D and 3D electric field simulator), MSGCSIM (simulating gas avalanche multiplication and induced charges) and SPICE (used for modeling signal propagation in a comprehensive network of the whole detector). The MSGC construction is based on the development of large-area multilayer de- position by means of plasma-enhanced CVD of insulating and resistive S1O2/DLC layers, separating the microstrip plane and the second coordinate plane 3 fxm be- low. Thus, in two-stage operation mode nearly non-attenuated induction of very fast signals (4-5 ns FWHM) is achieved on the lower plane, too. In this contribution the design parameter optimization by means of model calculations, results of the fabrication technology and the status of the detector fabrication are reported.
84 AT9900186
Poster B
Discharges in Microstrip Gas Counters B9
S. Keller, U. Werthenbach, G. Zech and T. Zeuner
Universitat-Gesamthochschule-Siegen, Siegen, Germany
The gas amplification of MSGCs in hadronic beams is severely limited by streamer discharges caused by strongly ionizing particles. We have irradiated MSGCs with an alpha source and studied the effect of different geometries and voltage settings. Various electrode materials, i.e. chromium, gold, aluminium, rhodium and tungsten were used. For a fixed gain the spark rate decreases with increasing drift field and increasing gap between anode and cathode strips. Also thick anodes are favorable. The degree of damage is mainly determined by the anode resistivity and capacity and less by the melting point and crystal binding energy of the metal. Amplitude and shape of the discharge pulses depend on the anode resistivity, the capacity of the anode cathode line, the length of the anode and the position of the spark. Sequetial discharge spikes are observed for badly conducting anodes. The measured signals Eire well reproduced by simulations which assume a low effective discharge resistivity for spark currents above a certain cut-off value.
85 AT9900187
Poster
The micro gap wire chamber (MGWC)
E. Christophel, M. Dracos and R. Strub
IReS, IN2P3-CNRS/Universite Louis Pasteur, Strasbourg Cedex 2, France
A new gas chamber configuration is described. It combines the geometry of the classical Multiwire Proportional Chambers and the one of the recently devel- oped Micro Gap Chambers (MGC). These new chambers consist of cathode strips (pitch=200 fim) and an anode wire plane (wire pitch=200 ^m) separated by thin dielectric strips (10 /im). The anode shape restores the cylindrical electric field con- figuration of the Multiwire Proportional Chambers lost by the MGCs due to their flat anode shape. Due to the small anode and cathode strip pitch, the spatial reso- lution is comparable with the one obtained by the Micro Strip Gas Chambers and MGCs. Gas gains higher than 105 have been obtained in stable conditions allow- ing the detection of single electrons. Using a current preamplifier, fast (rise time < 2 ns) and short signals (width ~25 ns) have been observed. Due to the MGWCs performance and to their 2D readout, this detector can be used as tracking detector at high rate experiments (LHC) or to detect single photoelectrons in Ring Imaging Cherenkov detectors. It can also be used in medical imaging detecting X-rays with high efficiency.
86 AT9900188
Poster B
TPC for heavy ion tracking and fragment identification on FRS at GSI Darmstadt
T. Baumannb. H. Geisselb, V. Hlinkaa, M. Ivanova, R. Janika, W. Schwab b, B. Sitara. P. Strmena and I. Szarkaa
^Institute of Physics and Department of Nuclear Physics, Faculty of Mathematic and Physics, Comenius University, Bratislava.Slovak Republic b GSI Darmstadt, Darmstadt, Germany
Time projection chambers (TPC) with delay line readout has been built as the co- ordinate detector for new generation of experiments on Fragment separator at GSI. The main advantage of this detector, in comparison with existing MWPC used in 4 FRS, is considerable lower amount of material in the beam region (<5E/E~10~ ); and better efficiency (~99.5%) Spatial resolution of 110 fj,m in X direction measured by delay line and 50 [im in Y direction measured by drift time has been achieved. TPC works as a true two-dimensional detector. Multiply (20 layers) dE/dx mea- surement allow to identify light fragments (Z=2-6) with the resolution better then 3a. A system of TPC on Pragmant separator considerably improved several pa- rameters of the spectrometer, mainly homogenity, spatial resolution and fragment identification. As a result energy resolution of High Resolution Energy Loss Spectrometer has been improved. Construction, and result from test and phys- ical experiments is presented.
87 AT9900189 B Poster
The Time-Expansion Chamber for the Phenix B 12 I Experiment at RHIC
ranz
Brookhaven Nat. Lab., for the Phenix Collaboration, Upton, USA
In the two central arms of the Phenix experiment at RHIC a set of 48 Time- Expansion chambers (TEC) will play a major role in tracking the 1500 charged particles per unit rapidity from the 100 A GeV/c Au + Au collisions. By sam- pling the energy loss of the particles a high level of electron/pion seperation can be achieved. A full size prototype was built and successfully tested at the AGS. Pro- duction of the final chambers has begun at BNL. The presentation will summarize the current status of the production, including an optical, non-contact method for measuring the wire tension, and highlight the testbeam results. AT9900190
Poster B
A Simple Theory for Resistive Plate Chambers B 13
Th. Heubrandtner, B. Schnizer1 and H. Schopf
Institut fur Theoretische Physik, TU Graz, Graz, Austria
A simple model for computing the current through the anode strips of a resistive plate chamber (RPC) is developed; a simple approximate but quite accurate formula for this current is found. The model is an infinite plane condensor filled with two layers; one is vacuum and represents the gas gap. The other one neighbouring the anode is a dielectric with a relative dielectric constant between 2 and 4; its weak conductivity is neglected as it has been shown by Schopf and Schnizer (WCC 1992) that for the high values of the specific resistance of the melamine-phenolic laminate or glass it has no influence on the signals so that the quasi-static approximation can be applied. The potential for a point charge representing the avalanche moving across the gas gap is calculated. Prom this the current flowing through a strip of the anode is derived. It turns out that the influence of the dielectric on the signal is also small and may be neglected; so a formula derived for an empty condensor and giving the strip current as function of the distance between the anode and the cathode, of the width of the strip and of the distance between the strip and the trajectory of the charge is a good approximation to the real case. A more refined model including a real gap between the anode strips again justifies the simple formula.
electronic mail: [email protected]
89 AT9900191
B Poster
Radiation damage of silicon strip detectors in the NA50 experiment
W. Dabrowski\ P. Grybosa, M, Idzika. S. Beoleb, P. Giubellinob, A. Marzari-Chiesab, M. Maserab, L. Ramellob and L. Riccatib
"•FPNT UMM Cracow, Cracow, Poland bINFN Torino, Torino, Italy
During operation of the Multiplicity Detector in the NA50 experiment the single sided ac-coupled p-on-n silicon strip detectors have been exposed to charged particle fluence up to 10E14 /cm2 and ionising doses up to lOMrad with a very non-uniform spatial distribution. In the paper measurements of radiation effects in the detectors used in the experiment will be presented. The full depletion voltage in the non- uniformly irradiated detectors has been evaluated from the efficiency measurements performed during the experiment as well as from the measurements of electrical parameters vs frequency and bias voltage performed after finishing the experiment. An electrical model for explanation of radiation effects observed in the detectors will be proposed.
90 AT9900192
Poster B
The Charged Trigger System of NA48 at CERN B 15
S. Anvar, F. Bugeon, P. Debu, J.L. Fallou, H. Le Provost, F. Louis, M. Mur, S. Schanne, G. Tarte and B. Vallage
DSM/DAPNIA CEA Saclay, Gif-Sur- Yvette Cedex, France
The NA48 charged trigger is a mixed hardware and software real time processing system intended to detect the interesting configurations of K° charged decays. It achieves real-time event building, track reconstruction and kinematics computation on drift chamber data at an event rate of 100 kHz and within a maximum decision latency of 100 fis. The system uses data driven. FPGA-based coordinate builders, a hardware event builder based on a crossbar switch, and a farm of up to 16 event processors for its software part. It has been installed and operated at CERN since 1995. After a description of the constraints and architecture of the various subsys- tems, the paper will give an account of the results and performance of the system based on the 1996/1997 runs. More specifically, the replacement of the present DSP-based implementation of the processing farm by RISC processors will be discussed.
91 AT9900193
Poster
The NA48 LKr Calorimeter Digitizer Electronics
B. Hallgrena, F. Bala, G. Barra, P. Buchholzb, A. Ceccuccia, F. Formentia, W. Funka, A. Gianolia, Yu. Kozhevnikov0, A. Lacourta, G. Laverrierea, A. Papid, M. Martinie, M. Sozzib, 0. Vossnacka, and H. Wahla
"•CERN, Geneva, Switzerland b Universitat Dortmund, Dortmund, Germany c Joint Institut for Nuclear Research Dubna, Moscow, Russia d Univ. degli Studi di Perugia, Perugia, Italy eDipartimento di Fisica, Univ. degli Studi di Ferrara, Ferrara, Italy {INFN, S.Piero a Grado, Pisa, Italy
The 13500 channels of the NA48 liquid krypton electromagnetic calorimeter read- out digitizer electronics have been put in operation in 1997. The digitizer electronics employs a gadn switching technique, which expands the dynamic range of a standaxd 10-bit ADC to 14 bits at 40 MHz sampling rate with the help of a custom developed integrated circuit (KRYPTON). The KRYPTON is a mixed analogue/digital inte- grated circuit, which contains the necessary functions for signal processing such as a 9-pole 10 MHz Bessel filter and four amplifiers with a multiplexer to drive the ADC combined with fast digital circuits to determine the signal amplitude. Additional functions integrated on the chip are a programmable trigger circuit for the NA48 neutral trigger and serial control circuits. The KRYPTON has been fabricated in 1.2 um BiCMOS technology and was successfully developed together with industry in a remarkably short time. The achieved performance and the experience from the first year of the operation of the liquid krypton calorimeter electronics will also be briefly discussed.
92 AT9900194
Poster B
The tagging detector of the CP-violation experiment B 17 I NA48 at CERN
H. Bergauera, H. Blumerb, M. Calvetti0, P. Cencic, H. Dibona, C. Ebersbergerb, K.H. Geibb, M. Jeitlera. K. Kleinknechtb, L. K6pkeb, P. Lubranoc, M. Markytana, I. Mikuleca, G. Neuhofera. V. Sch6nhartingb, A. Tauroka and A. Winhartb
&Institut fur Hochenergiephysik, Vienna, Austria bInstitut fur Physik, Universitat Mainz, Mainz, Germany cDipart. di Fisica, Univ. degli Studi di Perugia, Perugia, Italy
The CP-violation experiment NA48 at CERN uses simultaneous, almost collinear beams of neutral if£ and Kg mesons, which are produced on two different targets, to measure the effects of direct CP-violation in the decays of neutral kaons into 7r+7r~ and 7r°7T0. K% events are "tagged" by measuring the protons that fly towards the Kg production target. In order to sustain the high proton rate of 3* 107 protons in this beam without suffering from too many pile-up events, the detector consists of 24 separate scintillators, each of which sees only a small fraction of the beam. Their signals axe digitized by specially developed 1-GHz FADCs. The exact time of a pulse is established off line by a fit procedure. The detector and its electronics have been successfully used during test beams in 1994-1996 and during the first physics run of NA48 in 1997. The inefficiency of the detector has been measured to below 5 * 10~4. Sources of background have been identified to allow for off-line correction. The mechanical setup of the detector, the 1-GHz FADC and results from the test and data runs are presented. AT9900195
B Poster
A transient recorder system for applications in high rate detector systems
R. Stiehler. M. Adamek, H.J. Besch, M. Junk, G. Menzel. E. Neuser, W. Meissner, A. Sarvestani, N. Sauer, S. Volkov and A.H. Walenta
Universität Siegen, Fachbereich Physik, Siegen, Germany
Measurements with high-rate 2-dimensional gaseous detectors require an adequate data acquisition system which allows to handle and store the detector information. For this purpose a transient recorder system has been developed and tested at the University of Siegen. The system is based on 300MHz/8 Bit FADC hybrids. A 64 channel prototype ca- pable of working at a sampling frequency up to 140MHz with a sample-on-demand- mode has been used in a protein crystallography application. First measurements have been performed at the Synchrotron at LURE, Orsay/France. Slightly modified versions of the recorder system have successfully been adapted to other experiments such as dual-energy-tomography and the measurement of the Uranium-Lambshift at the heavy-ion-storage ring at GSI, Darmstadt, Germany. In these experiments the readout has been done by a PC using standard interfaces for PCI or AT-Bus. The system has been improved such that vast analogue delay lines, which have been neccesary in prior versions due to the sample-on-demand-mode were avoided. The experience with both 140MHz and 300MHz version of the transient recorder system as well as an outlook on a lGHz version, which is currently in development at the University of Siegen will be presented.
94 •iiiiiiHiiigi AT9900196
Poster B
The DT/CSC-Based First Level Muon Trigger of CMS B 19
A. Kluge and T. Wildschek
CERN, PPE, Geneva, Switzerland and HEPHY, Vienna, Austria
We present the design of the CMS first level muon trigger processor that is based on drift tubes (DT) in the barrel and cathode strip chambers (CSC) in the endcap. The processor searches for muon tracks originating from the interaction region by joining the trigger primitives provided by the chamber trigger logic of the DTs and the CSCs to track strings. It assigns transverse momenta to the reconstructed tracks using the tracks' bend angle and sagitta. High speed is achieved by performing the track reconstruction fully in parallel. In this contribution we present the algorithms, implementation and simulation results.
95 AT9900197
Poster
Use of a Big Liquid Argon Spectrometer BARS for B 20 I cosmic ray studies
S.V. Belikova, S.N. Gurzhieva, V.V. Lipaeva, S.V. Losa, A.N. Sytina, G. Gennarob, F. Sergiampietrib and G. Spandreb
"IHEP, Protvino, Russia hINFN - Sezione di Pisa, Pisa, Italy
The design of a fine grained 600t liquid argon calorimeter BARS is described. BARS electronics includes about 30k channels for low noise amplifiers and ADC's. DAQ system makes it possible to select channels with signal above the threshold chosen. 48 scintillation hodoscopes placed inside the liquid argon are used to form the 1- st level trigger. The total number of scintilation counters in liquid argon is 384. Sums of ionization signals are used to produce the 2-nd level trigger. Results of the first use of liquid argon calorimetry for precision measurement of cosmic ray muon spectra and composition of extensive atmospheric showers are discussed.
96 AT9900198
Poster B
The influence of exposure to air on the quantum B 21 I efficiency of thin Csl photocathodes
V.I. Razin. Yu.N. Gotovcev, A.B. Kurepin and A.I. Reshetin for the ALICE collaboration
Institute for Nuclear Research, Moscow, Russia
The ageing of a Csl film by exposure to air is discussed. Such exposures may take place during the transfer of a Csl photocathode from the evaporation vessel to the detector. The current (DC) was measured using a deuterium lamp for UV irradiation. It has been recorded in function of the length of exposure to air for the case of small photocathodes.A two hour expo- sure was found to have no remarkable effect but the current was decreased by 30 A simple technique for Csl evaporation has been developed.
97 AT9900199
B Poster
Forward Muon System for the DO Detector Upgrade B22
S. Gurzhieva for the DO Collaboration
^Institute for High Energy Physics, Protvino, Russia
Design and main parameters of the completly redesigned DO forward (Ij/eta/j2) muon system for the next high luminosity Tevatron Collider run are reported. The system consists of 48000 mini drift tubes and 4608 trigger scintillation counters with 1 ns time resolution. Results of the studies of trigger scintillation counters based on fast scintillator Bicron 404A and WLS bars SOFZ-105 are presented. Radiation aging of scintillating materials for the doses up to 1 Mrad, phototubes magnetic shielding in the fields of up to 700G and aging of phototubes for the accumulated anode charge up to 500C are presented. We report about results of test beam studies of prototype counters including minimum ionizing particles detection efficiency, time resolution and amplitude response. Trigger algorithms and muon track reconstruction in high rate environment of hadron collider experiment are discussed.
98 AT9900200
Poster B
Studies of Anode Blades for Gas Proportional B 23 I Detectors
B. Yu. G.C. Smith. D.P. Siddons and P.J. Pietrasky.
Brookhaven National Laboratory. Upton, NY, USA
The use of a thin metal edge, or blade, to generate controlled electron multipli- cation in a gas has been studied. Measurements with X-rays have been made on assemblies of an anode blade and two adjacent cathodes to determine optimum op- erating parameters in gas proportional mode, with the goal of producing position sensitive detectors with high resolution and high counting rate. Under specific con- ditions, energy resolution equal to the best from a wire proportional chamber can be achieved. The devices are very rugged and can be tailored to a curved geometry for the purposes of eliminating parallax error for small and large angle X-ray scattering experiments. The design of one such device, currently undergoing fabrication for a powder diffraction program using synchrotron radiation, will be discussed.
99 AT9900201
Poster
Simulation and improvements of the CAT (Compteurs B 24 I A Trous) a pixel gas proportional counter
M. Lemonnier. G. Chaplier, S. Megtert and M. Bordessoule
L.U.R.E Orsay, Orsay, France
With the help of an adapted simulation program we are able to define the conditions at the gas proportional counter built as C.A.T can work. This work leads to the very beginning of classification of detectors related to the CAT family.
100 List of authors
Adamek M. P B 18 Adzic P. P B 3 Akmadaliev S. TU 9H50 Albrecht E. P B 3 Ambrogiani M. FR 16H30 Anderson S. FR 15H15 Antoniades M. P A 18 Antropov A.E. P A 12 Anvar S. P B 15 Artuso M. FR 15H15 Atanasov I. P A 4 Avanzini C. TH 14H50 Azfar F. FR 15H15
Babichev E.A. P B 6 Bacchetta N. TH 10H15 Bachmann S. TU 15H15 Baechler J. TH 17H45 Bagnaia P. FR 11H30 Bal F. P B 16 Baldini W. FR 16H30 Barr G.D. P B 16 TH 14H50 Bartl W. P A 4 Baru S.E. P B 1 B 6 Baumann T. P B 11 Beaumont W. P A 8 TU 17H20 Beckers T. P A 8 TU 17H20 Beissel F. TU 15H15 Belikov S.V. P B 20 Bellazzini R. TU 14H50 Bencivenni G. TU 10H15 Benlloch J. TU 17H45 Benussi L. FR 12H20 Beole S. P B 14 Bergauer H. P B 17 Bertani M. FR 12H20 Besch H.J. I.T. MO 15H20 B 18 MO 17H45 MO 17H20 Bethge K. P A 10 Bettoni D. FR 16H3 0 Biagi S.F. WE 10H15 Bianco S. FR 12H20 Bischof H. I.T. ,FR 14H0 Bisello D. TH 9H50 Blinov A.E. P B 1 Blinov V.E. P B 1 Bluem P. P B 7 Bluemer H. P B 17 Bokemeyer H. P A 10 Bolotov V. P A 21 Bombonati M. FR 16H30 Bonsi D. FR 16H30 Bordessoule M. P B 24 Borisenko A. P A 21 Bouhali 0. P A 8 TU 17H20 Bracinik J. TH 17H45 Breskin A. FR 14H50 TU 18H10 Bressan A. TU 17H45 Brom J.-M. TU 16H55 Buchholz P. P B 16 Bueno C.C. TH 16H30 Bugeon F. P B 15
101 List of authors
Buzulutskov A. P A 9 FR 14H50
Cadeddu S. MO 17H00 Calabrese R. FR 16H30 Calafiura P. TH 14H50 Caligiore C. MO 17H00 Calvetti M. P B 17 Cambiaghi M. FR 11H3 0 Camps C. TU 15H15 Capeans M. TO 17H45 Caria M. MO 17H00 Carman D.S. TU 11H55 Carolino N. P B 4 Carugno G. WE 12H20 Catacchini E. P A 14 Ceccucci A. P B 16 Cenci P. P B 17 Cerron Zeballos E. TH 16H55 Challan-Belval H. P A 18 Chaplier G. P B 24 Chechik R. FR 14H50 TU 18H10 Chemloul M. P A 19 Chernenko S.P. P A 10 Chernyak D.V. P A 3 Chorowicz V. TU 16H3 0 Christophel E. P B 10 Ciampolini L. P A 14 Cirilli M. TH 14H50 Civinini C. P A 14 Cizeron R. TH 17H20 Clergeau J.F. TU 16H3 0 Coan T. FR 15H15 Commichau V. TU 15H1S Contardo D. TU 16H30 Costa L. P B 4 TH 16H3 0 Costantini F. TH 14H50 Cundy D. TH 14H50 Cussonneau J. P. WE 9H50 Cwiok M. TH 15H15 Czyrkowski H. TH 15H15
D'Alessandro R. P A 14 Dabrowski R. TH 15H15 Dabrowski W. P B 14 Damy M. TH 1SH3 0 Daumiller K. P A 4 De Troy J. P A 8 TU 17H20 Debu P. P B 15 Dibon H. P B 17 TH 14H50 Dickson M. P A 2 Dietl H. P A 13 Dix W.-R. MO 17H20 Doll P. P A 4 Dominik W. TH 15H15 Donois M. P A 18 Dracos M. P B 10 Duenger 0. MO 17H20 Durand A. TH 17H20 Duxbury D. WE 10H15 Dytman S.A. TU 11H55
102 List of authors
Ebersberger C. P B 17 Efimov A. FR 15H15 Emeliantchik I. P A 23
Fabbri F.L. FR 12H20 Fabjan C. P A 11 Fadeyev V. FR 15H15 Fallou J.L. P B 15 Fateev O.V. P A 10 Fedotov A.V. P A 12 Fedyakin N. P A 20 Feofilov G.A. P A 12 Ferreira-Marques R. P A 24 B 4 TH 16H30 Fischer G. TH 14H50 Fischer H.G. TH 17H45 Flammier M. TH 17H45 Fluegge G. TU 15H15 Focardi E. P A 14 Fontanelli F. P B 3 Fonte P. P B 4 WE 11H55 Formenti F. P B 16 TH 14H50 Fraga F.A.F. P A 24 Fraga M.M. TH 16H30 Franz A. P B 12 Fukatsu Y. P A 6 Fukui H. p A 6 Funk W. P B 16
Gabathuler E. WE 10H15 Gabriel A. P A 18 A 19 Garabatos J.M. P A 10 Garty G. TU 18H10 Gavalian V.G. P A 7 Gebauer B. P B 8 Geib K.H. P B 17 Geissel H. p B 11 Geld T.L. TH 17H20 Gennaro G. P B 20 Gianoli A. P B 16 Gianotti P. FR 12H2 0 Giardoni M. FR 12H2 0 Giomataris I.T. WE 09h00 Giubellino P. P B 14 Glonti L. P A 10 Goncalves J.A.C. TH 16H3 0 Goncalo J.R. P A 24 Goncalves J.A.C. P A 24 Gorbachev D. P A 3 Gorini B. TH 14H50 Gorski M. P A 17 TH 15H15 Gotovcev Yu.N. P B 21 Govyadinov A. P A 23 Gracco V. P B 3 Groshev V.R. P B 1 B 6 Gruwe M. TU 17H45 Grybos P. P B 14 Gschwendtner E. FR 11H55 Guaraldo C. FR 12H20 Gurzhiev S.N. P B 20 B 22
Hallgren B. P B 16 TH 14H50
103 List of authors
Hangarter K. TU 15H15 Haroutunian R. TU 16H30 Hasegawa Y. P A 6 Hatzifotiadou D. TH 16H55 Hendriks P. P A 13 Herten G. P A 11 Hessey N. FR 10H15 Heubrandtner Th. P B 13 Hlinka V. P B 11 Hoch M. TU 17H45 Hoffmann B. P A 4 Hollander R.W. P A 24 Hosoda T. P A 6
Idzik M. P B 14 Ignatov F.V. P A 3 Ikeno M. P A 6 Ischebeck R. TU 15H15 Ishida T. P A 6 Ivanov M. P B 11 Iwanski W. TH 14H50 Iwasaki H. P A 6 Izrailov E.K. P A 12
Janik R. P B 11 Jaworski Z. P A 17 Jeitler M. P B 17 TH 14H50 Jinnouchi 0. P A 6 Jung M. MO 17H20 Junk M. P B 18 MO 17H45
Kaercher K. P B 7 Kajetanowic M. P A 16 Kampert K.H. P A 4 Kapusta P. TH 14H50 Karig W. P A 10 Kasatkin V.A. P A 12 Keller S. P B 9 Kern H. P A 4 Khabakhpashev A.G. P B 6 Khazin B.I. P A 3 Kidon L. P A 16 Klages H.O. P A 4 Kleinknecht K. P B 17 Klempt W. P A 12 Kluge A. P B 19 Knoblauch D. P B 7 Kobayashi T. P A 6 Koch M.H.J. P A 19 Koenig W. P A 10 Koepke L. P B 17 Kolachev G.M. P B 1 Kollefrath M. P A 11 Kolojvari A.A. P A 12 Kopp S. FR 15H15 Korcyl K. P A 16 Korytov A. P B 2 Koskas G. P A 18 Kozhevnikov Yu. P B 16 Kozlov V.N. P B 1 Kraeber M. P B 7
104 List of authors
Kremp J. TU 15H15 Krolikowski J. TH 15H15 Krummenacher F. P A 19 Kubota Y. FR 15H15 Kudla I.M. P A 17 Kuehn W. P A 16 Kurepin A.B. P B 21 Kurilin A. P A 23 Kusano T. P A 6 Kuzmicz W. P A 17
Labbe J.C. TU 17H45 Lacourt A. P B 16 Laggner P. P A 19 Lai A. MO 17H00 Laico F. TH 14H50 Lamas-Valverde J. TH 16H55 Lanaro A. FR 12H20 Landgraf U. P A 11 Larin M.P. P A 12 Lautridou P. WE 9H50 Laverriere G. P B 16 TH 14H50 Lazanu I. P A 15 Lazanu S. P A 15 Lazarev V. P A 12 Le Provost H. P B 15 Legrand J.C. TH 17H45 Leingartner W. P A 19 Lemonnier M. P B 24 Lenzi M. P A 14 Leonidopoulos C. P B 5 Lepeltier V. TH 17H20 Linde F. P A 13 Lipaev V.V. P B 20 Lipeless E. FR 15H15 Lo Presti D. MO 17H00 Lohmann M. MO 17H2 0 Lorikian M.P. P A 7 Los S.V. P B 20 Louis F. P B 15 Lu C. P B 5 Lu J. FR 12H20 Lubrano P. P B 17 Lucherini V. FR 12H20 Lukin P.A. P A 3 Luppi E. FR 16H30 Luquin L. WE 9H50
Macke D. TU 15H15 Magahiz R. TU 11H55 Magazz G. TH 14H50 Majewski P. TH 15H15 Malyshev V. TU 9H50 Markou A. P B 3 Markytan M. P B 17 TH 14H50 Martini M. P B 16 Marzari-Chiesa A. P B 14 Masera M. P B 14 Maslennikov A. TU 9H50 Mattout J. TU 18H10 Maugain J.-M. FR 11H55
105 List of authors
Meadows B. TH 17H20 Mecozzi A. FR 12H20 Megtert S. P B 24 Meissner W. P B 18 MO 17H45 Mendiratta S. P B 4 TH 16H30 Menelle A. P A 18 Menk R.H. MO 17H20 MO 17H45 Menzel G. P B 18 Meschini M. p A 14 Mestayer M.D. TU 11H55 Metivier V. WE 9H50 Metri R. P B 7 Mikenberg G. P A 6 Mikulec I. P B 17 TH 14H50 Minakov G.D. P B 1 Mio H. p A 19 Mirabito L. TU 16H30 Miskimen R. TU 11H55 Mitselmakher G. I.T. FR 9H00 Miyazaki Y. P A 6 Mohr W. P A 11 Morelli A. P B 3 Morettini P. P B 3 Morsani F. TH 14H50 Mountain R. FR 15H15 Muanza S. TU 16H3 0 Mueller J.A. TU 11H55 Mueller Th. P B 7 Muentz C. P A 10 Mur M. P B 15 Musa L. TH 17H45 Mussa R. FR 16H3 0
Neinashkalo A. P A 21 Neuberger D. P B 7 Neuhofer G. P B 17 TH 14H50 Neuser E. P B 18 Niewczas M. P A 17 Niezurawski P. P B 3 Novikov I.A. P A 12 Nowack A. TU 15H15 Nozaki M. P A 6
Ohska T. K. P A 6 Onuchin A. TU 9H50 Onuchin A.P. P B 1 FR 16H55 Ottonello P. P A 5
Panebianco S. MO 17H00 Papi A. P B 16 Parrini G. P A 14 Paschhoff V. P A 11 Passamonti L. FR 12H20 Peleganchuk S. TU 9H50 Pentchev L. P A 4 Pepy G. P A 18 Pernegger H. TH.11H3 0 Pernicka M. P B 3 TH 14H50 Peskov V. P B 4 WE 11H55 Petri M. P A 16 Petrolini A. P B 3
106 List of authors
Petrosyan S.S. P B 1 Petta C. MO 17H00 Piana G. P B 3 Pierazzini G.M. TH 14H50 Pieri M. P A 14 Pietrasky P.J. P B 23 Pietraszko J. P A 16 Pikna M. TH 17H45 Placci A. TU 17H45 Platner E. TH 16H55 Policarpo A.J.P.L. P A 24 B 4 TH 16H30 Pontecorvo L. FR 11H30 Pooth 0. TU 15H15 Popov A.S. P A 3 Popov V. P A 21 Porcu M. TH 14H50 Porcu P. MO 17H00 Porosev V.V. P B 6 Pospelov G. TU 9H50 Potapov S.V. P A 12 Pozniak K.T. P A 17 Prager M. FR 14H50
Rabsch G. P A 4 Radeka V. TH 12H20 Rahmani A. WE 9H50 Ramello L. P B 14 Ramillien V. WE 9H50 Ramsey B.D. WE 11H55 Randaccio P. MO 17H00 Randazzo N. MO 17H00 Razin V.I. P B 21 Reirae B. MO 17H20 Reito S. MO 17H00 Reposeur T. WE 9H50 Reshetin A.I. P B 21 Riabov V. TU 11H30 Riccati L. P B 14 Rizzi D. TH 14H50 Roberts J. TH 16H55 Rohrbach F. FR 11H55 Ronan M. TH 17H20 Ropelewski L. TU 17H45 Rossi F. TH 14H50 Rottigni G.A. P A 5 Ruban A. P A 3 Rubashkin A. P A 21 Russo G.V. FR 12H20 MO 17H00 Rylin A.V. P B 1
Sadrozinski H. TH 11H55 Salabura P. P A 16 Sartori C. P A 5 Sarvestani A. P B 18 MO 17H45 Sarwar S. FR 12H20 Sauer N. P B 18 MO 17H45 Sauli F. I.T. MO 14H30 TU 17H45 TU 18H10 Savinov G.A. P B 1 B 6 Schaknowski N.A. TH 12H20 Schanne S. P B 15 Schinzel D. I.T. TU 9H00
107 List of authors
Schleif G. P A 4 Schmidt B. I.T. TU 14H00 Schmidt F.K. P A 4 Schnizer B. P B 13 Schoenharting V. P B 17 Schoepf H. P B 13 Schuh S. FR 15H15 Schulte R. TU 15H15 Schulz Ch. P B 8 Schumacher R.A. TU 11H55 Schwab W. P B 11 Schwartz A. J. P B 5 Sciolla G. TU 12H20 Sedykh Y. FR 11H55 Sen S. TH 17H20 Senchishin V. P A 21 Serdyouk V. FR 12H20 Sergiampietri F. P B 20 Shamov A.G. P B 1 Sharma A. TH 18H10 Shefer E. FR 14H50 TU 18H10 Shekhtman L. P A 9 Shusharo A.I. P B 1 Sibidanov A.L. P A 3 Siddons D.P. P B 23 Simonis H.J. P B 7 Sitar B. P B 11 TH 17H45 Skoczen A. P A 16 Skrebtsov 0. P A 21 Skwarnicki T. FR 15H15 Smadj a G. TU 16H30 Smith A. FR 15H15 Smith G.C. P B 23 TH 12H20 Smykov L. P A 10 Snopkov I.G. P A 3 Solodov E.P. P A 3 Solomey N. FR 17H20 Sorokin P. P A 21 Sozzi M. P B 16 TH 14H50 Spandre G. P B 20 Spegel M. P A 11 Stancari G. FR 16H30 Stavropoulos G. P A 13 Steigerwald A. P A 10 Stelzer H. P A 10 Stiehler R. P B 18 MO 17H45 Stolyarov O.I. P A 12 Stone S. FR 15H15 Strmen P. P B 11 Stroth J. P A 10 Strub R. P B 10 Sytin A.N. P B 20 Szarka I. P B 11 Szymanski P. TH 17H45
Takeshita T. P A 6 Talyshev A.A. P B 1 Tarte G. P B 15 Taurok A. P B 17 TH 14H50 Tedeschi D.J. TU 11H55 Telnov V.I. P B 6
108 List of authors
Thompson R.A. TU 11H55 Thuemmel W.H. P B 7 Tikhonov Y. TU 9H50 Tonutti M. TU 15H15 Topp U. P A 11 Torassa E. FR 9H50 Treichel M. P A 11 Tripiccione R. TH 14H50 Trischuk W. I.T. ,TH 9H0 Tsimbal F.A. P A 12 Tulina T.A. P A 12
Udo F. P A 8 TU 17H20 Ullaland 0. P B 3
Valassi A. TH 17H20 Valiev F.F. P A 12 Vallage B. P B 15 Van Doninck W. P A 8 TU 17H20 Van Dyck C. P A 8 TU 17H20 Van Lancker L. TU 17H20 Vander Velde C. P A 8 TU 17H20 Vanlaer P. P A 8 TU 17H20 Veenhof R. WE 11H3 0 Velasco M. TH 14H50 Verbeure F. P A 8 TU 17H20 Viehhauser G. FR 15H15 Viertel G. MO 18H15 Vinogradov L.I. P A 12 Volkov A. FR 12H20 Volkov S. P B 18 Volobouev I. FR 15H15 Vossnack 0. P B 16 TH 14H50 Vreeswijk M. P A 13
Wahl H. P B 16 TH 14H50 Wajda E. P A 16 Walenta A.H. P B 18 MO 17H45 Wegst R. P A 4 Weilhammer P. I.T. TH 14HO0 Werthenbach U. P B 9 Wildschek T. P B 19 Williams M.C.S. TH 16H55 Wilpert Th. P B 8 Winhart A. P B 17 Wolff T. P A 22 Worms er G. TH 17H20 Woudstra M. P A 13 Wuestenfeld J. P A 10
Yamauchi K. P A 6 Ye J. FR 15H15 Yoshida M. P A 6 Yu B. P B 23 TH 12H20 Yushkov A.N. P B 1
Zabierowski J. P A 4 Zanella G. P A 5 Zanewsky Yu. V. P A 10 Zannoni R. P A 5 Zatserklianiy A. P A 21
109 List of authors
Zech G. P B 9 Zentek A. P A 10 Zeuner T. P B 9 Zhukov V. P A 8 TU 17H2 0 Zia A. FR 12H20 Zichichi A. TH 16H55 Ziolkowski M. TH 14H50 Zumbruch P. P A 10 de Lima E. P. TH 16H3 0 de Raad Iseli C. P A 19 de Santos S. TH 16H30 van Eijk C.W.E. P A 24 van den Berg F. P A 24
110 List of Participants
Adam, W., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Aiginger, H., Atominst, d. Österr. Universitäten, A Aleksa, M., CERN, EP, CH Asatiani, T.L., Nat. Academy of Sciences, ARM Asaturian, R., Yerevan Physics Institute, Laboratory of position sensitive detectors, ARM Augustin, J.-E., Univ. Claude Bernard Lyon I, IPNL, F Azzi, P., INFN Padova, High Energy Physics, I Bachkirov, V., MEPHI, RU Bachmann, S., RWTH Aachen, ID. Physikalisches Institut B, D Baechler, J., CERN, EP, CH Bartl, W., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Battiston, R., University and INFN of Perugia, I Beckers, T., Universitaire Instelling Antwerpen, Physics Department, B Behnke,O.,DESY,FHl,D Bellazzini, R., INFN-Pisa, CMS, I Bencivenni, G., Laboratori Nazionali di Frascati - INFN, Research Division, I Benussi, L., INFN-Laboratori Nazionali di Frascati, Research, I Bernstorff, S., Trieste, Experimental Division Sincrotrone, I Besch, HJ., Universität Siegen, Fachbereich Physik, D Bettoni, D., INFN - Sezione di Ferrara, I Biagi, S., Liverpool University , Physics Department, UK Bianco, S., INFN-Laboratori Nazionali di Frascati, Research, I Bischof, H., TU-Wien, Abt. Mustererkennung u. Bildverarbeitung, A Blanar, G., LeCroy Corporation, Research Systems Division, USA Blinov, V., Budker Institute of Nuclear Physics, Elementary particles, RU Bosio, C, INFN-Roma, I Botta, E., I.N.F.N. Sezione di Torino, I Bouhali, O., U.L.B Faculte des sciences, HHE cp 230, B Bozzo, M., CERN and INFN-Genova, EP, CH Bracinik, J., Comenius University, Inst. of Physics, SK Breskin, A., Weizmann Institute, IS Bressan, A., CERN, EP, CH Brez, A., INFN-Pisa, CMS, I Brom, J.-M., 1RES - Strasbourg, F Budtz-Joergensen, C, Danish Space Research Institute, DK Buzulutskov, A., Budker Institute of Nuclear Physics, Elementary particles, RU Calabrese, R., Universita' di Ferrara, Dipartimento di Fisica, I Capeans, M., CERN, EP, CH Caria, M., University of Cagliari, Physics Department, I Carman, D., TJNAF, Physics, USA Carugno, G., I.N.F.N., PADOVA SECTION, I Casimiro, E., CINVESTAV-IPN, Physics Department, Mexico Castelli, E., University of Trieste, Dept. of Physics, I Charpak, G., CERN, EP, CH Chechik, R., Weizmann Institute, IS Chernenko, S., Joint Institute for Nuclear Research, Lab. of High Energy Physics, RU Chochula, P., HEPHY, A Comparât, V., I.S.N, F Contardo, D., CNRS, IPN Lyon, F Cser, L., Res.Inst. Solid State Phys., Neutron Physics Dept., H Cwiok, M., Institute of Experimental Physics Warsaw University, Particles and Fundamental Interactions, PL D'Alessandro, R., I.N.F.N. Firenze, I Dangendorf, V., Physikalisch-Technische-Bundesanstalt, Neutronendosimetrie, D Davenport, M., CERN, EP, CH De Troy, J., Universitaire Instelling Antwerpen, Physics Department, B Del Guerra, A., University of Ferrara, Department of Physics, I Denisov, S., IHEP, RU Dias, T., Universidade de Coimbra, Departamento de Fisica, P Dick, L., CERN, EP, CH
111 List of Participants
Dickson, M., Cornell University, Nuclear Studies, USA Didierjean, F., Eurisys Mesures, R&D, F Doll, P..IK1, D Dominik, W., Warsaw University, Institute of Experimental Physics, PL Dracos, M., IRES - Strasbourg, F Duerdoth, I., The University of Manchester, Dept of Physics and Astronomy, UK Eckardt, V., Max-Planck-Institut f.Physik, Experimentalphysik, D Emelianchik, I., Nat. Center of Part, and High Energy Phys., BL Erin, S., BflEP (Institute for High Energy Physics), EP(experimental physics), RU Fabbri, F., INFN-Laboratori Nazionali di Frascati, Research, I Fediakine, N., Institute for High Energy Phisics, Neutrino physics department, RU Feofilov, G., Institute for phisics, Theory department, RU Fischer, G., CERN, EP, CH Fliigge, G., RWTH Aachen , III. Physikalisches Institut B, D Foeth,H.,CERN,EP,CH Fontaine, J.-C, IUT de Mulhouse, GMP, F Fraga, F., LIP-Coimbra, Dep. Fisica Univ. Coimbra, P Fraga, M.M., LIP-Coimbra, Dep. Fisica Univ. Coimbra, P Franz, A., Brookhaven National Laboratory, RHIC - Phenix, USA Freund, P., Max-Planck-Institut f.Physik, Experimentalphysik, D Frischauf, N., Osterr. Akademie d. Wissenschaften, Institut fur Hochenergiephysik, A Friihwirth, R., Osterr. Akademie d. Wissenschaften, Institut fur Hochenergiephysik, A Fukui, H., Kobe University , Faculty of Science , J Gabriel, A., EMBL, Instrumentation, F Gallin-Martel, L., Institut des sciences nucleaires, SDI, F Gebauer, C, Hahn-Meitner-Institut Berlin, FK, D Geltenbort, P., Institute Laue-Langevin, Science, F Gensch, U., DESY, D Geyer, R., Forschungszentrum Juelich , IKP, D Gornik, E., TU-Wien, Institut 363, A Gottfried, Ch., Osterr. Akademie d. Wissenschaften, Institut fiir Hochenergiephysik, A Griesmayer, E., Med-Austron, A Grimm, O., University of Hamburg, II. Institut fuer Experimentalphysik, D Gschwendtner, E., CERN, EP, CH Guevorkov, L., Russian Academy of Sciences, Inst. of Nuclear Research (INR), RU Gurzhiev , S., Institute for high energy physics , Neutrino physics department, RU Hacker, J., Osterr. Akademie d. Wissenschaften, Institut fur Hochenergiephysik, A Hallgren, B., CERN, EP-ATD, CH Hauschild, M., CERN, EP, CH Heino, J., Helsinki Institute of Physics, Particle Physics Program, SU Hermes, E., Universitat Zyrich, Physik Institut, CH Hessey, N., LMU Munich, EP, CH Heubrandtner, T., TU Graz, Institut fur Theoretische Physik, A Hladky, J., Inst of Phys. Czech Acad Sci, High Energy Physics, Czech. Republic Hrubec, J., Osterr. Akademie d. Wissenschaften, Institut fur Hochenergiephysik, A Hudek, P., Slovak. Academy of Sciences, SK Huss, D., IUT de Mulhouse, GRPHE, F Iacovacci, M., UNIVERSITY OF NAPLES, DEP. OF PHYSICS, I Idzik, M., University of Mining and Metallurgy, Faculty of Physics and Nuclear Techniques, PL Ivanov, M., Comenius University, Inst. of Physics, SK Iwata, S., Nat. Lab. for High Energy Physics (KEK), J Jeitler, M., Hephy, CH Joram, Ch., CERN, EP, CH Kantardjian, CERN, EST-LEA, CH Khomutov, N., Joint Institute for Nuclear Research, Laboratory of Nuclear Problems, RU Klempt, W., CERN, EP, CH Klett, A., EG&G BERTHOLD, Radiation Protection & Detectors, D Koch, M. H.I., EMBL, Hamburg, D Koetz, U., DESY, ZEUS/F35, D Kok, E., NIKHEF, ET, NL
112 List of Participants
Kollefrath, M, Universitaet Freiburg, Fakultät für Physik, D Korytov, A., University of Florida, Physics, USA Kotthaus, R., Max-Planck-Institut f.Physik, Experimentalphysik, D Kowalski, T., Univ. of Mining &MetalIurgy, Fac. of Physics &Nuclear Techniques, PL Kramarenko, V., Moscow State Univ., Inst. for Nuclear Physics, RU Krammer, M., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Krell, Ch., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Krivchitch, A., Petersburg Nuclear Physics Institute, High Energy Physics Division, RU Krizan, P., University of Ljubljana, Department of Physics, SK Kroha, H., Max-Planck-Institut f.Physik, Experimentalphysik, D Kudla, I., Warsaw University, Institute of Experimental Physics, PL Kuhn, D., Univ. Innsbruck, Exp. Physik, A Kutschera, A., Univ. Wien, Inst. f. Radiumf. u. Kernphysik, A Laggner, P., Österr. Akademie d. Wissenschaften, Inst. f. Röntgenfeinstrukturforschung, A Lamas-Valverde, J., CERN, EP, CH Lang, K., The University of Texas at Austin, Department of Physics, USA Lautridou, P., cnrs-in2p3 Subatech, Ecole des Mines de Nantes, F Lazanu, S., National Institute for Materiuals Physics, Semiconductor Laboratory, RO Leder, G., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Lemonnier, M., LURE, Detectors, F Lepeltier, V., LAL, Laboratoire de l'Accélérateur Linéaire, F Lipaev, V., Institute for High Energy Phisics, Neutrino physics department, RU Lohmann, M., University of Siegen, Department of physics, D Lorikyan, M.P., Yerevan Physics Institute, ARM Lu, C, Princeton Univ., Physics Department, USA Lumb, N., INFN-Pisa, CMS, I Lupu, N., Technion I .IT., Physics, IS Luquin, L., cnrs-in2p3 Subatech, Ecole des Mines de Nantes, F Mac Cormick, M., IPN ORSAY, Division de la Recherche Experimentale, F Macke, D., HL Physikalisches Institut B RWTH Aachen, CMS, D Maggiora, A., INFN, I Majewski, S., Jefferson Lab, Physics Division CEBAF, USA Malychev, V.L., Joint Institute for Nuclear Research, Lab. of High Energy Physics, RU Mandl, F., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Marka, S., Vanderbilt University, Physics and Astronomy, USA Marstaller, R., Max-Planck-Institut f.Physik, STAR-group, D Masik, J., Inst, of Physics, Czech. Republic Meissner, W., Universitaet Siegen, Fachbereich Physik, D Menk, R., Elettra Trieste, SAXS, I Menzione, A., 1st. Naz. di Fisica Nucleare (INFN), Sez. di Pisa, I Mestayer, M., Jefferson Lab, Physics Division CEBAF, USA Mikulec, I., Österr. Akademie d. Wissenschaften, Institut für Kernphysik, A Mio, H., Inst, for Biophysics and X-Ray Structur Research of the Austrian Academy of Sciences, Instrumentation, A Mitaroff, W., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Mitselmakher, G., Unin. of Florida, Dept. of Physics, USA Musnig, G., AKH-Wien, A Neuhofer, G., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Niebuhr.C, DESY,FH1,D Nikouline, V., PNPI, HEPD, RU Onuchin, A., Budker Institute of Nuclear Physics, Elementary particles, RU Paschhoff, V., Universitaet Freiburg, Fakultät für Physik, D Patarakin, O., RNC Kurchatov Institute, RU Pentchev, L., Institute for Nuclear Research and Nuclear Energy, High Energy Physics, BL Pépy, G., CEA, LLB / CEA Saclay, F Perez-Ochoa, R., CERN, EP, CH Pernegger, H., Massachusetts Inst. of Technology, Lab. Nuclear Science, USA Pernicka, M., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Peskov, V., NASA/MSFC, Astrophysics, USA Petrakovic, G., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A
113 List of Participants
Petrolini, A., Universita" di Genova and INFN sezione di Genova, Facolta* di Scienze, I Peyre, J., IPN Orsay, R&D Détecteurs, F Pikna, M., Comenius University, Inst. of Physics, SK Pinsky, L., University of Houston, Physics Department, USA Piredda, G., INFN, Sezione di Roma, I Placci, A., CERN, EP, CH Poljanc, K., Med-Austron, A Pontecorvo, L., INFN-Roma, Physics, I Pooth, 0., RWTH Aachen, III. Physikalisches Institut B, D Popov, P., Saint-Petersburg University , Nuclear Physics Department, RU Porosev, V., Budker Institute of Nuclear Physics, Elementary particles, RU Pouthas, J., IPN Orsay, R&D Détecteurs, F Puill, G., CEA Saclay, DSM/DAPNIA/SED, F Rachev, M., Saint-Petersburg University, Nuclear Physics Department, RU Rakoczy, D., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Regler, M., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Renfordt, R., CERN, EP, CH Reposeur, T., cnrs-in2p3 Subatech, Ecole des Mines de Nantes, F Riabov, V., PNPI, High Energy Division, RU Ridky, J., Inst. of Physics, Czech. Republic Rohrbach, F., CERN, EP, CH Rohringer, H., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Rondeshagen, D., Universität Münster, Institut für Hochenergiephysik, D Ropelewski, L., CERN, EP, CH Rosinsky, P., Comenius University, Department of Nuclear Physics, SK Rosta, L., Res.Inst. Solid State Phys., Neutron Physics Dept., H Sadrozinski, H.F.-W., UC Santa Cruz, SCIPP, USA Salin, P., College de France, LPCC-CNRS-IN2P3, F Santos, F., Universidade de Coimbra, Departamento de Física, P Sarvestani, A., Univeisitaet Siegen, Fachbereich Physik, D Sarwar, S., INFN-Laboratori Nazionali di Frascati, Research, I Sauli, F., CERN, EP, CH Scherberger, G., Universitaet Freiburg, Fakultät für Physik, D Schinzel, D., CERN, EP, CH Schmidt, B., Univ. Heidelberg, Physikal. Institut, D Schmidt, F., Universität Erlangen-Nürnberg, Physikalisches Institut Abteilung II, D Schnizer, B., TU Graz, Institut für Theoretische Physik, A Schulz, Ch., Hahn-Meitner-Institut, FK, D Schumacher, R., Carnegie Mellon University, Department of Physics, USA Schune, P., CE-Saclay, Particle Physics, F Sciolla, G., Stanford Linear Accelerator Center (SLAC), USA Semenov, S., Moscow Phys. Engineering Inst., RU Sharma, A., GSI Darmstadt, EP, CH Shary, V., Budker Institute of Nuclear Physics, Spherical Neutral Detector group, RU Sheaff, M., UniUniversity of Wisconsin, Dept. of Physics, USA Shefer, E., Weizmann Institute, I Sibidanov, A., Budker Institute of Nuclear Physics, Elementary particles, RU Sidorov, V., Budker Institute of Nuclear Physics, Elementary particles, RU Simonis, H.J., Universität Karlsruhe, IEKP, D Skrk, D., Jozef Stefan Institute, Experimental Particle Physics, SK Smith, G.C., Brookhaven National Laboratory, Instrumentation Division, USA Sokolov, A., Budker Institute of Nuclear Physics, RU Solomey, N., The University of Chicago, Enrico Fermi Institute, USA Souvorov, V., DESY, HERA-B, D Spandre, G., INFN-Pisa, CMS, I Spegel, M., CERN, EP, CH Spinelli, P., INFN, Dip. of Physics, I Stanovnik, A., University of Ljubljana, Faculty of electrotechnics, SK Stassi, P., Institut des sciences nucléaires, SDI, F Stefanini, A., UNIVERSITY OF PISA, Physics Department. I
114 List of Participants
Stiehler, R.-H., University of Siegen, Dept. of Physics, D Stroth, J., IKF, D Taurok, A., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Terrien, Y., CEN-SACLAY, DAPNIA/SPhN, F Tikhonnov , Y., Budker Institute of Nuclear Physics, Elementary particles, RU Tomasek, L., Inst. of Physics, Czech. Republic Torassa, E., ENFN-Padova, I Toseilo, F., I.N.F.N.- Sezione di Torino, I Trischuk, W., University of Toronto, Physics Department, CD Turala, M., CERN/INP Cracow, EP, CH Urbanek-Spegel, I., ,F Vallage, B., CEA, DSM/DAPNIA/SPP, F Van den Berg, F., DU, ISO, NL Vaniachine, A., Royal Inst. of Technology, Physics Department, S Va'vra, J., Stanford Linear Accelerator Center (SLAC), USA Veenhof, R., NIKHEF Amsterdam the Netherlands, CERN-PPE, CH Viehhauser, G., Syracuse University, Physics Department, USA Viertel, G., ETH - Zurich, High Energy Physics, CH Vrba, V., Inst. of Physics, Czech. Republic Vreeswijk, M, CERN, EP, CH Wajda, E., Jagellonian University, Nuclear Physics, PL Walter, M., DESY, HERA-B, D Weilhammer, P., CERN, EP, CH Weinstein, L., Old Dominion University, Physics Department, USA Weisenberger, A., Thomas Jefferson National Accelerator Facility, Physics, USA Wenig, S., CERN, EP, CH Werthenbach, U., University of Siegen, Physics Department, D Wildschek, T., CERN, EP, CH Wilmsen, W., OMV AG, A Wilpert, T., Hahn-Meitner-Institut, RE, D Winkler, M., Österr. Akademie d. Wissenschaften, Institut für Hochenergiephysik, A Zanella, G„ Università di Padova, Dipartimento di Fisica "G.Galilei", I Zanevsky, Y., Joint Institute for Nuclear Research, Lab. of High Energy Physics, RU Zannoni, R., Università di Padova, Dipartimento di Fisica "G.Galilei", I Zatserklianiy, A., Kharkov Institute of Physics & Technology, HEP. Ukraine Zeitelhack, K., TU-München, Physik-Department E12, D Zeuner, T., DESY / University of Siegen, F15 / Physics Department, D Zontar, D., Jozef Stefan Institute, Experimental Particle Physics, SK
115 STRUCK More than a good link Electronics for Higi Energy Physics and Industry
Scalable VME based higher level Trigger and Readout Instrumentation for PCOS, FERA and other ECL Frontend Systems
We are proud to announce the availability of a modular high performance readout system, which allows the experimenter to acquire data from proportional wire chambers instrumented with Le Croys PCOS readout, Le Croys FERA system, other ECL data streams and combinations of these sources. The system was designed for applications with first level trigger rates in excess of 100 KHz.
First Application The system was developed for the readout of the focal plane polarimeter at the KVT Groningen in close co-operation with the University of Munster. In this application the system has to read data from four sets of MWPCs with PCOS3 readout and ADCs and TDCs digitizing the information from scinitillation counters in FERA. The second level trigger decision is based on the deflection • • #• * • • DS P DS P FIF O FIF O i between the incoming and outgoing beam, :--;y!*dS«t:v-.| events with a scattering angle above a i ^ \ VME \ threshold will be accepted. The anticipated n DSPs {n depending on required computing first level trigger rate is 100 KHz, after the pew) second level reduction rate of some 99% the full accepted events will be read out. 1 FIFO rvbdule per front end crate
System Setup STR7090 VME ECL input FIFO The system consists of three different types of The STR7090 is a single width 6 U VME VME modules, one or several STR7090 ECL board with 32 bit ECL input via 2 34 pin input FIFOs, one or several STR8090 DSP headers at 10 MHz (20 MHz on request). The boards and one arbiter module. Every ECL default FIFO size is 4K longwords, up to 64K data stream is fed into one ECL FIFO, and the can be installed. An event structure is data are read out event based via a local bus, implemented by means of an event counter which is implemented by means of a cable bus FIFO, several end of event conditions are on the P2 backplane, by the STR8090 DSPs available. For the efficient readout of 16 bit under control of the arbiter module with a data streams a packing mode is implemented. transfer time of 60 ns per 32-bit word. The Data can be read out via the VME bus or a number of DSPs can be scaled according to local bus on the P2 connector. In conjunction the required computing power, full events are with a standard VME master the STR7090 distributed among the available units by the ECL input FIFO can also be operated as a arbiter unit. An overall system setup is standalone readout solution for ECL data sketched below. streams. A block diagram of the FIFO is shown below.
Dr. B. Struck BSckerbarg 6 D-22889 Tangstedt email: [email protected] www:http://www.struck.de Tel.: 04109/550 Fax: 04109/55133 STRUCK More than a good link Electronics for Higji Energy Physics and Industry
STR8090 VME DSP Board read into the STR8090 via the input FIFO and processing can take place in parallel on the The STR8090 is a single width 6U VME DSP incoming data stream. The processed data are board on the base of the Motorola 96002 written to an output FIFO, which can be floating point DSP. It is designed to acquire accessed from VME. DSP Software is data from a variety of sources and to perform developed in C or assembly language on a PC online processing. In the ECL readout or on a workstation under a DOS emulator application the DSP can be used in and downloaded to the DSP via VME by a conjunction with the STR7090 ECL FIFO for DSP master. data formatting, extraction of higher level trigger information and similar tasks. Data are
STR7090 Block Diagram
STR8090 Block Diagram
Dr. B. Struck Backerbarg 6 D-22889 Tangstedt email: [email protected] www:http://www.struck.de Tel.: 04109/550 Fax: 04109/55133 just happens where everyone meets
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