Vancouver Accelerator Conference

Michael Craddock, Chairman of the Conference, and Accelerator Research Division Head at the TRIUMF Laboratory gives the opening address at the 1985 Particle Accelerator Conference in Vancouver. He and his colleagues are to be congratulated on the very smooth organization of such a large gathering.

Anyone who contends that particle physics is conducted in an ivory tower, not contributing to other fields of science or to humanity at large, should have attended the 1985 Particle Accelerator Confer­ ence in Vancouver. Over a thou­ sand participants contributed 781 papers and only a fraction were actually related to accelerators for nigh energy physics. The majority of present developments are in the service of other fields of science, for alternative power sources, for medicine, for industrial applica­ tions, etc. Nevertheless, it is the spur of high energy physics that has dri­ ven accelerator technology along. As Burt Richter pointed out, in some fifty years since the first Cockcroft-Walton accelerators were built, accelerator physicists have increased peak machine energies by a factor of a million and have reduced the cost per GeV by a factor of over ten thou­ larly the machine diameter. ing problems, good cooling and sand. Conference Chairman Mike Though there are variants - with straightforward \)raddock rejoiced in his opening such as two-in-one (both beam ap­ manufacturing processes. Address that the contributions of ertures in a single yoke) or one-in- Paul Reardon reported on the al­ the accelerator community had one designs - there are essentially ternative high field type for which been so significantly recognized at two basic magnet types now un­ the initially separate proposals of the end of the last year with the der consideration. The superferric, Fermilab and of Brookhaven/ award of the Nobel Prize to accel­ low field type aims for simplicity Berkeley have now been amal­ erator physicist Simon van der and attendant low cost. Work on gamated in what is called 'Design Meer, jointly with Carlo Rubbia, their design (reported by Russ Hu- D'. They have built 4.5 m proto­ for his part in the success of the son) is at the Texas Accelerator types, 4 cm aperture, plus other CERN proton-antiproton Collider. Centre where most impressive prototypes for specific purposes, progress has been made for such and have been encouraged by the a newly created team. They have recent improvements in supercon­ The big machines built and tested a series of 1 m ductor cable quality (mentioned Maury Tigner, Head of the Cen­ and 7 m magnets, concentrating also in the recent story on HERA tral Design Group based at Berke­ mostly on a two-in-one design, at DESY, see June issue, page ley, gave an overview of progress and are now assembling a 28 m 179) giving 25 kA/mm2 rather than towards the US 20 TeV Supercon­ prototype (their aim is magnet the 18 kA/mm2 of the cable used ducting Super Collider, SSC. Their units 140 m long, including di- for the Fermilab Tevatron, which next major decision is the selec­ poles 105 m long, of which there makes higher fields accessible. Six tion of the type of magnet, which would be 1330 around the ring). 17 m magnets are now under con­ of course carries a host of other Magnet performance has been struction; they are one-in-one, 4 parameters in its wake - particu­ good with no training, no quench- cm bore, cold iron.

CERN Courier, July/August 1985 223 The 1985 Particle Accelerator Conference gets underway. The Conference, the eleventh in the series (based in the USA prior to this excursion over the northern border), was held from 13 to 16 May, attracting over a thousand participants.

A look at operational considera­ tions (Peter Liman) does not give a clear message on low field versus high field magnets for the SSC. The low field, larger ring would be some 5 to 10 per cent more ex­ pensive to operate. The high field is more susceptible to trouble from collective effects and from synchrotron radiation (new to pro­ ton machines) in cryogenic condi­ tions. Some experiments are planned on the Brookhaven 'Light Source' to give better estimates of the potential radiation problems. To retain its key attraction, how­ ever, the low field type will have to retain comparative simplicity of construction. As designs advance, it is not obvious that this will defi­ nitely be the case. Site selection for the SSC is the most 'political' of the project deci­ sions, apart of course from the overall project authorization. Jim Sanford described the present thinking on site l*ayout. A 'compos­ arcs, which will lead beams from the CERN proton-antiproton Colli­ ite' site has been invented in order the upgraded SLAC linac into colli­ der (Bas de Raad and Robin Lauck- to spell out the needs and get a sion, is complete and some 900 ner) and the Fermilab Tevatron (G feeling for costs. The Department bending magnets for the arcs are Dugan). The Collider performance of Energy has set up a selection available. The aim is to start com­ climbed to an integrated luminos­ procedure (involving outside missioning of the arcs in the au­ ity of almost 400 nb"1 in 1984 (see experts) and the hope is that the tumn of 1986. On the linac itself, page 229) and the current pro­ decision would be taken at the end the electron gun is giving over 5 x gramme of improvements - partic­ of 1986. If everything goes accord­ 1010 per bunch, the tiny damping ularly the construction of ACOL to ing to schedule, and authorization ring has stored 4 x 1010 electrons, give an order of magnitude im­ for the project is forthcoming, new focusing and guidance sys­ provement in the number of anti- construction could begin in 1988. tems are being installed and the protons stored per day (1012 rather Of the big machines already un­ klystron and SLED upgrade of the than 1011) and a change to six der construction, we have reported linac is meeting specification. bunch operation - should take the recently on LEP (May issue, page The TRISTAN 30 GeV electron- luminosity to about 4.4 x 1030 per 132), covered at the Conference by positron collider project at the cm2 per s with coasting beams at Herwig Schopper, and HERA (June Japanese KEK Laboratory was 315 GeV. The recent pulsed opera­ issue, page 179), covered by Bjorn mentioned in an overview of ac­ tion of the Collider sacrificed lumi­ Wiik. The Stanford Linear Collider, celerator projects in Japan by Y. nosity to take a look at higher to achieve 50 GeV electron-posi­ Hiras. The 2.5 GeV injector is oper­ collision energies (up to 450 GeV) tron collisions and to prepare the ating and the accumulation ring is and, in a very successful machine way for very high energy lepton now being commissioned. run, provided 95 hours of physics. colliders, was covered by S. Eck- News from the big machines Commissioning of the antipro- land. All the tunnelling for the two presently in operation concerned ton source at the Tevatron started

224 CERN Courier, July/August 1986 on 10 May. The antiproton yield scribed some of the new ideas microwave amplifier was achieved with the lithium lens in operation before (see, for example, Decem­ at the end of last year. The idea is has been measured as 3 x 10~5 ber issue 1984, page 436), and to use a low energy, high current per proton. Previously the de- several schemes remain in favour (few MeV, 1 kA) beam through a buncher ring was checked out with - particularly laser beat waves, wiggler to produce copious micro­ 8 GeV protons and beam was wake field and two-beam wave radiation (35 GHz) via the stored for the first time in April; schemes. FEL mechanism. This radiation now it is the turn of the accumula­ C. Joshi reviewed those involv­ then passes energy to a second tor ring where the stochastic cool­ ing access to the high accelerating beam by activating a high gradient ing systems are installed. The field of laser beams (1 TV/m trans­ structure. Such a structure has superconducting ring has been verse). A number of exploratory been made for the experiment (re­ tested as a storage ring with pro­ experiments are underway or pro­ quiring Swiss watch dexterity in tons and has held beam for four posed at the UK Rutherford Labo­ manufacture and assembly) and hours. The hope is that antipro- ratory, in Canada, and at UCLA tests should be underway at Liver- tons will be transferred to the and Los Alamos in the US. At more soon. If all goes well, there

Tevatron in July and that the first UCLA a C02 laser experiment has are dreams of a 30 m prototype by proton-antiproton collisions will be achieved accelerating fields of up the end of the decade. observed in August. Operation is to 1 GV/m via beat waves in plas­ likely to be at energies up to 800 mas. Over the next few years it is GeV per beam, pushing to 1000 hoped to demonstrate acceleration Applications of accelerators in GeV later. of electron beams with such beat other areas of science waves. Joshi emphasized that this research with lasers will be fruitful If the above paragraphs are al­ Accelerator technologies for the in any case since the special char­ ready a cursory summary of the future acteristics of the laser fields will flood of information communi­ be applicable in other areas such cated at the Conference, we now While the above paragraphs as the focusing of beams, ion move to topics where the volume communicate that the accelerator guns and power sources. of presented papers was even community has much to keep it Tom Weiland described work on greater. We, therefore, take a se­ busy in the cause of particle phys­ the wake field scheme at DESY. lective look at accelerator develop- ics for some years to come, there The immediate aim is to demon­ ements in branches of science is also the realization that with LEP strate that short pulses of high other than particle physics concen­ and SSC we are bumping into gradient fields (over 100 MeV/m) trating on synchrotron radiation physical and fiscal limits in the can be achieved in structures sources, neutron sources, heavy climb to the ever higher energies where the wake fields left by hol­ ion accelerators and kaon facilities. demanded by the particle physi­ low beams in an outer channel are The explosion in the use of syn­ cists. Thus, despite the burden of transformed through to a central chrotron radiation from electron- present projects, some hardy souls beam aperture. A test unit to pro­ positron storage rings, plus wig­ have started the very long term duce doughnut-shaped electron gler and undulator additions to search for new methods of accel­ beams has had encouraging initial extend the range of the light beam eration which would bring down tests and it is hoped to have tried characteristics, was evident in the the size and cost of the next centu­ the wake field transformer princi­ talks of Mark Barton, Lee Teng and ry's machines. ple by the end of the year. Michael Knotek. Barton listed 23 The technologies need to be Work based at Berkeley on the operating facilities (18 of them radically different. Recent ad­ two-beam scheme was reported dedicated light sources) in Europe, vances, like the hard won mastery by Don Hopkins. They are benefit­ Japan, USA and USSR. Teng of superconducting magnets and ting from the availability of the added about 20 others now under radiofrequency cavities, do not free electron laser facility at Liver- construction or proposed and it take us far enough beyond pre­ more where the first ever opera­ was pleasing to note that some of vious techniques. We have de­ tion of a FEL as a high gain these are in countries outside the

CERN Courier, July/August 1985 225 The main social event took the participants out to TRIUMF on the campus of the University of British Columbia where they could tour the Laboratory and enjoy a salmon barbecue, Indian style. The weatherman decreed that this should be the one rainy day of an otherwise sunny week, which drove the barbecue indoors. Even with this complication, the excellent organization ensured a very pleasant evening. above usual geographic locations - Brazil, China, India and Taiwan. To give an idea of just how heavy the demand is for the use of each of these light sources, the National Synchrotron Light Source at Brookhaven operates eighteen beamlines with seventeen more planned on the X-ray ring and thir­ teen beamlines with eleven planned on the ultra-violet ring. The most advanced machines are 6 GeV, very high brightness proposals in the USA (designs from Argonne, Brookhaven and Stanford) to use full energy injec­ tion into the light source storage ring after a booster synchrotron, with many long straight sections for wigglers and undulators. Such a facility was recommended by the 'Seitz-Eastman Committee on Ma­ jor Facilities for Materials Re­ search', and preparatory Workshops have been held at Ames and the National Bureau of Standards. Almost equivalent dynamic systems to be studied), proton beam energies up to 550 thinking is behind the design pro­ medicine (just one potential appli­ MeV rather than the design 800 posed for a European Synchrotron cation in preventive medicine is MeV (while awaiting installation of Radiation Facility (reported in a picked out below), industrial uses the last two of the six r.f. acceler­ poster session by S. Tazzari). The (crystal studies for the semicon­ ating cavities). There is no devel­ European design has electron en­ ductor industry, lithography, mi­ opment on the authorization of the ergy of 5 GeV with thirty straight croscopy, etc.) are also benefitting spallation neutron source, SNQ, sections (we will have an article from access to synchrotron radia­ proposed at Julich in Germany. on the ESRF in the near future). tion facilities. The acceleration of heavy ions is Knotek commented that the availa­ David Gray reported on initial back in the news and Nick Samios bility of such machines will bring operation of the Spallation Neu­ spelled out some of the reasons a revolution in X-ray science tron Source at the Rutherford Ap- why. The most intriguing for parti­ equivalent to that experienced pleton Laboratory which is taking cle physics is that colliding high when moving from the old X-ray over from the neutron sources at energy heavy ions could allow ac­ sources to the first light beams Argonne, Los Alamos and KEK as cess to short distances between from electron synchrotrons. the most prolific source of neu­ components in the nucleons In addition to the great impact trons for research. Proton acceler­ where the force acting between on all areas of materials research ators bombarding uranium targets quarks is weak (the quark-quark at the present light sources, re­ surrounded by moderators are ca­ binding force increases with dis­ search workers in other disci­ pable of neutron fluxes far higher tance). Thus heavy ion collisions plines, such as biology (where the than those of high flux beam react­ could open up for study a new speed at which information can be ors. The research programme at state of matter - the quark/gluon gathered allows complex struc­ Rutherford started in June, contin­ plasma. Energies of some 100 GeV tures, like proteins, viruses, and uing to the end of the year with per nucleon are probably neces-

226 CERN Courier, July/August 1985 Lee Teng, seen here touring the TRIUMF installations with his wife, gave a Conference report on the booming area of synchrotron radiation applications.

R and D. The size of the user com­ munity interested in such heavy ion experiments in the USA is esti­ mated at up to 400 scientists. In the meantime, there are some interesting intermediate develop­ ments in Europe. At CERN, oxygen 16 ions will bq accelerated through the PS and SPS and the possibility of antiproton-ion collisions has not escaped attention. For a broader programme, D. Bohme reported that authorization has recently been given for the construction of a synchrotron, SIS, to be fed by the existing UNILAC linear ion ac­ celerator at GSI Darmstadt (see June issue, page 181). UNILAC provides ions at some 20 MeV per nucleon; SIS will take energies to 1 GeV per nucleon for uranium ions. It will be linked to an Experi­ mental Storage Ring, ESR, which is being designed. Construction time is some four to five years (dominated by the building con­ struction). sary but the colliding ion beam lu­ with superferric magnets. Kaon factory proposals were re­ minosities need not be very high Brookhaven are working hard on viewed by H.A. Thiessen. The aim ^1026 per cm2 per s or less). a 100 GeV per nucleon collider is to build a high intensity proton A. Ruggiero reviewed schemes known as the Reiativistic Heavy machine in the 30 to 50 GeV range to reach such machine perform­ Ion Collider, RHIC. Beams from the to produce (amongst other beam ance. The Bevalac at Berkeley has existing tandem will be transferred species) a flux of kaons some been the front runner in heavy ion to the Alternating Gradient Syn­ hundred times higher than those energies for many years reaching chrotron (the transfer line is being available from the CERN PS and the range of 1 GeV per nucleon for built and the AGS r.f. system is Brookhaven AGS for research in fixed target physics. They have being modified to accept ions). nuclear and particle physics. The had the ambitious VENUS project Eventually a booster synchrotron Los Alamos, TRIUMF, SIN, Brook­ on the table since 1979 (see Dec­ would be added to allow injection haven and KEK Laboratories have ember 1979 issue, page 406) to of fully stripped ions. From the all looked at the possibilities; the reach energies of 20 GeV per nuc­ AGS, accelerated ions would be first two have developed propos­ leon in colliding beams and, in the fed to storage rings installed in the als. Project preparation is most ad­ absence of authorization, have a completed tunnel which was for vanced at Los Alamos where the more modest version (the 'Mini the CBA/ISABELLE project. (Since, LAMPF linear accelerator would be Collider') for colliding beams at 4 for some purposes, heavy ions used as injector into a booster and GeV per nucleon in rings with 4 T could extend down to protons, it fast cycling synchrotron. At superconducting magnets. Oak has to be acknowledged that RHIC TRIUMF the injector would be the Ridge have a proposal for a 10 is a most imaginative way of existing cyclotron into booster, GeV per nucleon collider using building the CBA!) A proposal has synchrotron and storage rings. ions from their operating tandem been put forward and construction TRIUMF have obvious interest in into two synchrotron/storage rings could take off in 1988 after further opening up a new programme;

CERN Courier, July/August 1985 227 the existing cyclotron has been in apy facility) and neutrons (for weapon. There were a few papers action for a decade (in fact there example, at Fermilab - a total of at the Conference from laborato­ will be a celebration of Ten Years over 4000 have been treated in the ries clearly involved in such stud­ of Scientific Research at TRIUMF USA). ies which mainly reported work on 7, 8 July). Certainly, if they Because it is so elegant, we aimed at improving the quality of build kaon factories as well as mention in addition one recent low energy particle beams. There they organize Conferences they idea for a medical application was certainly no open information would do an impressive job! which is under investigation - which can yet move the particle It was intriguing that heavy ion heart scans using synchrotron beam weapon out of the category machines and kaon factories got radiation (reported by H. Wieder- of science fiction. so much attention at the Confer­ man). What is needed is a small The interest in particle beams to ence - they were second and third (1.2 to 1.5 GeV) high intensity (1 achieve commercially viable fusion priorities, respectively, in the rec­ A) light source able to provide a reactors via the inertial confine­ ommendations for the Nuclear high flux of photons of energy 33 ment technique continues and Physics Advisory Commitee con­ keV. Iodine is introduced into the there were review papers on light cerning the facilities most appro­ bloodstream and one scan of the ion (M. Buttram) and heavy ion priate for nuclear physics reseach heart (with some 108 photons per (Dennis Keefe) developments. The in the coming years. The first mm2) is done with the photon en­ aim is to deposit several mega- priority machine, a recirculating ergy just below the iodine K ab­ joules on the surface shell of a linac to give 4 GeV electron sorption edge and a second with deuterium-tritium pellet in some beams, did not figure at the Con­ the energy just above. The read­ 10 ns requiring accelerators deliv­ ference though preparatory work ings of these scans are subtracted, ering a few terawatts. (Buttram re­ is underway at the Virginia site of one from another, via computer. marked that the calculations the Southern Universities Re­ The only thing that changed in the ranged 'from the optimistic to the search Association, SURA, under two readings is the photon flux conservative to the realistic'.) San- the project name of CEBAF (Con­ absorbed by the iodine in the dia is concentrating on producing tinuous Electron Beam Accelerator bloodstream. Thus, the coronary beams of 30 MV lithium ions. A Facility). arteries appear with remarkable 100 TW machine called PBFA-II is clarity while the rest of the anat­ scheduled for operation early next omy 'disappears'. Such scans year to study beam and target be­ Some applications of accelerators could readily give advance warn­ haviour under single pulse condi­ ing of potential heart troubles and tions. They use a high power To conclude, we mention a few the economic values of such warn­ pulse compression scheme with of the Conference topics where ac­ ings (quite apart from the humane laser triggered spark gaps. celerators are used or planned, not social value) would be great. The For heavy ions, a bank of r.f. lin- for particle physics or other areas technique is very much faster and acs cascading ions into an Alvarez of scientific research, but directly more pleasant for patients than linac, followed by transfer and in 'practical' applications. the presently used techniques. storage rings, remains under study Medical applications have been It is impossible to report on an in Europe and Japan. The alterna­ a major spin-off ever since the first Accelerator Conference which con­ tive scheme using induction linacs X-ray machines. Now accelerators centrated mostly on the work of is pursued in the USA. An induc­ are in use for isotope production, the USA community without a few tion linac, MBE-4, to demonstrate in radiography, and in particle words about a proposed practical current amplification with four beam therapy. For therapy, var­ application going in the opposite caesium ion beams is under con­ ious accelerated particles are used direction to medical applications - struction at Berkeley. - heavy ions (in particular at the Strategic Defense Initiative, Also related to fusion reactor Berkeley), protons (2600 people SDI, beloved of the media as 'Star technology is the Fusion Material have been treated at the Harvard Wars'. One of the mechanisms to Irradiation Test (FMIT), a 35 MeV cyclotron), pions (the TRIUMF Lab­ be studied under SDI for 'zapping' deuteron accelerator to provide in­ oratory itself has a pion radiother­ alien objects is the particle beam tense fluxes of neutrons of fusion

228 CERN Courier, July/August 1985 Collision course

reaction energies. These neutron On 10 July 1981, Carlo Rubbia two orders of magnitude from beams will be used to study the burst into the Lisbon Particle 5 x 1027 per cm2 per s in 1981 to behaviour of materials subjected Physics Conference clutching the 3.5 x 1029 cm~2 s~1 in 1984. More to the bombardment they will re­ first recordings of high energy important, the daily average per­ ceive in fusion reactors. Several collisions of matter and antimatter formance (integrated luminosity) papers reported progress on the in the CERN SPS ring. His an­ has increased by more than an machine development (for exam­ nouncement, the culmination of order of magnitude. ple, the successful operation at many years of intense and careful In view of the scarcity of anti- Los Alamos of appropriate radio- preparation, was greeted with protons, the reliability of the frequency quadrupoles for the spontaneous applause. whole chain of injectors is of cru­ FMIT injector; it is amazing how More than three years later, the cial importance. The SPS itself is the new technology of RFQs has SPS Collider's performance has particularly vulnerable to faults, swept the board in accelerator in­ improved more than a hundred­ due mainly to its large size and jection systems in the space of a fold, but the applause has died heavy demands on primary serv­ couple of years). down. With the collection of anti­ ices. matter mastered and almost rou­ After the first proton-antiproton This report of the Vancouver tine, Lyndon Evans and Vincent collisions were recorded in the Particle Accelerator Conference Hatton review the achievements summer of 1981, the first physics will give some feeling for the to date and the lessons learned. run took place at the end of that range and the volume of modern year, when 2 x 1032 per cm2 (0.2 accelerator physics and technol­ The Collider's peak luminosity nb-1) of integrated luminosity was ogy. (a measure of the instantaneous produced. In the second run at proton-antiproton collison rate) the end of 1982 the peak luminos­ By Brian Southworth has been pushed up by almost ity was increased to 5 x 1028 cm-2

Emerging from the tunnel wall on the right is the beamline which feeds 26 Ge V antiprotons from the PS to the CERN SPS. On the left are proton lines emerging from the SPS main ring.

(Photo CERN 38.4.81)

CERN Courier, July/August 1985 229 The control room - nerve centre of SPS operations.

(Photo CERN 169.6.83)

s_1 and a total integrated luminos­ of accelerators. At least three transfer up to the very last mo­ ity of 28 nfcr1 was produced, days of stacking of antiprotons in ment if a fault is detected. Such enough to reveal the long-awaited the antiproton accumulator (AA) elaborate software control is more? W particle. In the spring of 1983 is required before making the first reminiscent of a rocket launch the peak luminosity was pushed transfer to the SPS with an initial than an accelerator operation. up to 1.7 x 1029 cm~2 s~1 and a to­ luminosity in excess of 1029 cm-2 In the first three years of opera­ tal of 153 nfcr1 was produced in s~1. Once the initial stack is estab­ tion, useful luminosity could be each of the two experiments. Fi­ lished, equilibrium is reached maintained for some 15 hours, nally in the latest big run (end where approximately 30 per cent being limited mainly by the anti­ 1984) the peak luminosity was of the stack is transferred to the proton beam lifetime. This is well further increased to 3.5 x 1029 SPS in three bunches. As long as suited to the cadence of one anti­ crrr2s~1 and a total of 395 nb~1 the SPS can hold the beams for of proton transfer per day. If the was produced in each experiment. the order of 20 hours, the AA then coast is terminated manually the These runs used continuously has time to replenish the stack SPS is prepared for the next injec­ stored (d.c.) beams, first at a colli­ ready for the next transfer. tion as quickly as possible. Gener­ sion energy of 540 GeV, then in The security of the transfer se­ ally three or four hours are 1984 at 630 GeV. This year (see quence is improved by using soft­ necessary to follow fully all the May issue, page 131), a new tech­ ware. The nucleus is a high level procedures, retune the machine, nique was used in which the colli­ job manager called the 'sequen­ check the beamlines with protons, sion energy attained 900 GeV for cer'. This controls the complex se­ inject antiproton pilot pulses, etc. brief periods. ries of operations needed to However, as will be shown later, The steady improvement in Col­ prepare the SPS and its transfer at least one third of the coasts are lider performance reflects a grad­ lines and to control the antiproton terminated prematurely. In these ual mastering of a complex chain injection process. It can abort the cases it is often unattractive to

230 CERN Courier, July/August 1985 Erwin Gabathuler (CERN Research Director at the time, second from left) had promised a crate of champagne if the maximum proton-antiproton collision luminosity achieved in the SPS during the initial operations in 1981 could be increased tenfold in the 1982 run. Enjoying his generous offer with him are (left to right) Andre Faugier, Lyndon Evans (one of the authors of this article), Jacques Gareyte and Robin Lauckner. Luminosity has since been boosted considerably and more champagne has appeared from time to time. (Photo CERN 209.11.82)

Hitting a barn

Integrated luminosity is a way of gauging the total number of collisions over a period of lime. An area is imagined to surround an an-

tiproton, sayr and one asks how many times a proton went through this area. The nanobarn, the area com­ monly used in particle phys­ ics is tiny - 10~33 cm2. A 'barn' (10~24 cm2) is the target area offered by big nuclei like uranium, and even in the old days of nu­ clear physics, hitting these giant nuclei was 'as easy as hitting a barn'. The name stuck.

prepare quickly for a new fill since in duty factor from 43 per cent to due to a technical failure. time is needed for the accumula­ 50 per cent. Access requests are grouped to­ tor to replenish its stack. In the early stages of an experi­ gether and scheduled as much as There has also been a gradual ment there is little demand for possible in advance since full use increase in the percentage of time peak luminosity performance and has to be made of these relatively available for experimental physics it is the total number of hours rare occasions. It is not unusual to compared to the total scheduled with collisions which is important. have 30 people entering the UA1 operating hours. This is also the case at the begin­ zone for a four-hour access pe­ Other than providing beams for ning of a new period of operation, riod. Shorter accesses between the experiments, there are four and there are also demands for fills are also catered for. other time-consuming tasks: set­ low luminosity calibration runs. Access for accelerator repairs is ting up for coasts, machine stud­ The time requested for calibration combined with access to experi­ ies, access, mainly for the and setting up runs in any year ments. Much of the power supply experiments, and fault diagnosis however is small, less than 10 per testing and improvement was and equipment repair. cent of the total scheduled time. done during access to the experi­ The efficiency of the Collider is The average time for setting up mental zones. judged by the experimental teams in preparation for a fill is nearly Machine studies require a vari­ on the combined basis of total six hours. This reflects the de­ ety of beam conditions. In addi­ hours of colliding beam and lumi­ pendence on the number of anti- tion to studies on the end of a nosity. Thus the figure which protons available in the physics coast, time needs to be really counts is the integrated lu­ accumulator rather than any inef­ set aside for proton-only coasts minosity. Its increase by a factor ficiency in the preparation. The and collisions with pilot (low in­ of 2.6 from 1983 to 1984 was time between fills is particularly tensity) antiprotons. Both these more significant than the increase long following the loss of a stack uses of scheduled time are neces-

CERN Courier, July/August 1985 231 The most important single external perturbation at the SPS is voltage fluctuation on the main 380 kV overhead feeder lines, which are especially vulnerable during summer thunderstorms.

(Photo CERN 126.5.75) sary for the efficient operation and development of the accelera­ tor and the experiments and should not be considered as counterproductive. Of the 77 coasts in the 13-week 1984 run, 25 were terminated pre­ maturely due to technical failures. For the rest the average store du­ ration was 17 hours. The 1984 re­ cord was 31 hours and the all- time record is 42 hours. If a coast lasts longer than seven hours, the chances are it would be 'killed' by the crew at the end of its useful life. The coast ceases to be useful for physics after the luminosity has fallen. The useful luminosity lifetime for most of 1983 and 1984 was less than 20 hours, typically between 13 and 15 hours. Of course any decision is dependent upon another fill being available. If there were problems with the proton/antiproton supplies, the coast was kept longer, hence the random failures, mostly minor target operation. occasional exceptionally long and unrelated. During fixed target For the increase from 273 to coasts. At the end of the coast for operation (53 per cent of total 315 GeV coasting energy in 1984, physics, machine studies would scheduled time per year for phys­ one modification was the installa­ frequently occupy another two ics) faults are analysed and re­ tion of booster water pumps in all hours. paired with the more stringent sextants of the ring. The upgrade There was a tendency to favour collider operation in mind. was very successful, but two a 24-hour cycle of filling. Equip­ Voltage dips on the mains sup­ coasts were lost. Diagnosis and ment that is used only during the ply (on an overhead line directly effective elimination of the fault transfer, injection and acceleration from a hydroelectric source at can be hampered by human er­ process can only be tested out of Genissiat, 50 km from CERN) con­ rors owing to the lack of familiar­ coast mode; it is more efficient to tributed about 30 per cent of the ity with such new conditions. uncover problems during the nor­ technical failures in 1982 and Striking a balance between relia­ mal working hours of the labora­ 1983. In the latter part of the 1983 ble operation and the need to im­ tory. run and for the 1984 period, the prove running conditions is a As the useful luminosity lifetime system was desensitized to stand constant dilemma. increased from 20 to about 26 dips of up to 25 per cent on any Care must be taken that all hours and equipment reliability of the three phases before the magnets acting on the primary improved, the 24-hour cycle was power supplies tripped. The SPS beams are engineered to the abandoned in favour of increased Collider never operates during the same high standard as the accel­ coast time and higher integrated summer months. Evening thun­ erator components. Some coasts luminosity. derstorms are common in July have been lost because detector In 1983 and 1984, the majority and August and have caused seri­ magnets have failed to respond of technical faults were caused by ous perturbations even for fixed correctly (the necessary balance

232 CERN Courier, July/August 1985 between the magnet and its com­ culty must be included in the soft­ While the performance im­ pensator magnets has sometimes ware so that the human element provements achieved so far at the not been observed). can be minimized. Once an opera­ SPS Collider are impressive, the tional procedure is established it ingenuity and resourcefulness of should never be overlooked and the operating teams is far from Beam quality this logically means converting it exhausted. We can hope to see into software. many more antiproton milestones The SPS Collider's operation is For good beam quality and di­ in the years to come. restricted by the availability of an­ agnostics it is important to have tiprotons. The required degree of good databanks not only of the Reliability of its equipment must equipment parameters but also of be higher and loss of stored beam the beam characteristics. Being is more serious than in the case able to study the evolution of a of a proton-proton collider. parameter over a number of shots But all colliding beam machines is very important and encourages have to provide stable conditions lateral thinking. with low backgrounds over long As in any other storage ring the periods of time. This is beam operation of the SPS as a proton- quality. antiproton collider imposes se­ Good operation needs good di­ vere demands on equipment reli­ agnostics. In the case of the Colli­ ability. The scarcity of antiprotons der, the measurements of beam in particular excludes fast refilling parameters and confidence in the after equipment failure and makes results is of paramount impor­ the impact of such faults on the tance. In fact the performance im­ overall productivity particularly provement has been closely dramatic. correlated with the development The Collider is particularly vul­ of improved diagnostics. Uncer­ nerable to fluctuations in the pri­ tainty caused by a doubtful meas­ mary services. The most urement can hinder an important single perturbation out­ investigation, preventing a logical side the control of the SPS team diagnosis. Without reliable meas­ is voltage fluctuation on the main urements, problems of high back­ 380 kV supply. This problem is ac­ ground, for example, cannot be centuated by the long exposed traced to a movement in the overhead feeder lines to CERN, closed orbit due to magnet drifts and excludes colliding beam op­ or distinguished from a problem eration in periods of thunder­ with the beam scraping system. storm activity (most of the One high background problem summer). was finally traced to a noisy linear The average time of 5.9 hours potentiometer which controlled needed to refill the machine is the position of a collimator block; mainly determined by the number once identified the problem was of antiprotons available in the ac­ quickly solved, but many hours cumulator. Nevertheless, the were spent following false trails. achievement of the best possible Important in the seach for im­ beam quality, transfer efficiency, proved beam quality is for the emittance, etc. requires a very control system to accommodate careful, systematic setting-up for flexible operation. New ideas and each fill, needing at least two or newly identified sources of diffi­ three hours.

CERN Courier, July/August 1985 233 A quarter of a century against the clock

25th anniversary time. Derek Lowenstein (left), chairman of Brookhaven's Alternat­ ing Gradient Synchrotron (AGS) Depart­ ment, presents a backwards-running clock to Ernest Courant, one of the pioneers of the AGS, which produced its first counter­ clockwise protons 25 years ago.

Twenty-five years ago, on 17 May 1960, the gleaming new Alternat­ ing Gradient Synchrotron (AGS) at the Brookhaven National Labo­ ratory, New York, got its first taste of protons. But it took a few more months to prepare the radiofre- quency system which transformed the new ring from a toy into the most powerful particle accelerator in the world. On 29 July 1960, protons were whipped through the dreaded phase transition and accelerated to the 30 GeV design energy. The AGS had wrested the high energy crown from CERN's new Proton Synchrotron, which had achieved 24 GeV just five months previously. The AGS was the first proton accelerator project to incorporate from the start the revolutionary idea of strong focusing. In 1952, Brookhaven's Cosmotron, an old- style weak focusing machine, had supplied its first 3 GeV protons - the first time the 1 GeV barrier ward, some outward. in the American Library in Athens. had been breached. The same The initial idea was just to get On a trip to the US in 1952, he year, a group of European ma­ easier access to positive beams, saw the classic strong focusing chine specialists (Edouard Regen- but soon bigger payoffs became paper by Courant, Livingston and streif, Frank Goward, Odd Dahl evident. Collaborator Ernest Cour­ Snyder, and went along to Brook­ and Rolf Wideroe) from the infant ant found that rather than damag­ haven to tell them he had done it CERN came out to see what was ing the proton orbits, the new all before. John Blewett (also part happening. They were toying with idea seemed to improve the fo­ of Livingston's study group) the idea of building a scaled-up cusing. Hartland Snyder recog­ writes 'at first we thought he was version of the Cosmotron as the nized an analogy with optics, a phony but gradually facts first big machine for their new where alternate focusing and de- emerged to support his claim. We Laboratory. focusing lenses of equal strengths changed our minds and offered Cyclotron pioneer Stan Livings­ are focusing, no matter which him a job, which he accepted.' ton organized a study group to comes first. With the stronger fo­ The CERN team, which had un­ consider what advice Brookhaven cusing, magnet apertures could wittingly breathed hard enough could give the Europeans. During be cut from the 8 x 24 inches of down Brookhaven's neck to make the deliberations, Livingston had the Cosmotron down to matchbox Livingston and Co. come out with a brainwave. The Cosmotron size. something special, hurriedly magnets all faced outwards, mak­ (Unknown to the Brookhaven changed the design of their new ing it easy to extract negatively team, this idea had already been machine in midstream. At Brook­ charged particles from a target in developed by a Greek lift engineer haven, Leland Haworth persuaded the machine, but not positive called Nick Christofilos whose the US Atomic Energy Commis­ ones. Livingston's idea was to hobby was particle accelerators sion, very concerned with secret have some magnets facing in­ and who read the Physical Review work in those days, to let Brook-

234 CERN Courier, July/August 1985 haven publish the new ideas, and tery of CP-violation - the cunning J/psi particle and opened the door a modest six-page letter proposed way the neutral kaons break the to charm and more new physics. the building of the machine which rules of conventional physics. In (The J/psi was simultaneously was to become the AGS. (At Cor­ the same year, an AGS experi­ discovered by Burt Richter at nell, the strong focusing tech­ ment led by Nick Sarpios spotted Stanford.) nique was immediately the omega-minus particle, and a Against this impressive list of incorporated into a new electron new way of looking at physics achievements, the CERN PS had synchrotron which began opera­ suddenly clicked into place. only one of sipnilar stature - the tions in 1954.) The CERN team, Thanks to these and other dis­ sighting in 1973 of the neutral lender the direction of the late coveries in the 1960s, Brookhaven current of the weak interaction. Vohn Adams, went on to get their took over from Berkeley as the But by then the PS had embarked proton act together faster than world's premier particle physics on a new career, supplying pro­ Brookhaven. Laboratory. As if to confirm that tons to the big SPS machine built After the suspense of the con­ the initial bumper crop of results alongside. struction race, the AGS and the was no flash in the pan, a 1974 Towards the end of the 1970s, CERN PS machine embarked on experiment led by Sam Ting at a ambitious plans were again being their separate careers. There the more mature AGS discovered the formulated at Brookhaven and story was different. At the AGS in Pioneers of the AGS Brookhaven CERN. At Brookhaven, the AGS 1962, a team led by Mel Schwartz, Alternating Gradient Synchrotron alongside would feed the big ISABELLE pro­ an early scale model which showed the Leon Lederman and Jack Stein- great reduction in AGS magnet aperture ton-proton collider. At CERN, the berger discovered that there were compared to that of the Brookhavep SPS was already operating with Cosmotron thanks to the invention of the two types of neutrino. In 1963, alternating gradient focusing system. From particles from the PS. The plan James Cronin and Val Fitch made left to right are a youthful Ernest Courant, was to adapt the SPS to work as a Stanley Livingston, Hartland Snyder and the AGS beams reveal the mys­ John Blewett. proton-antiproton collider as well as a proton accelerator. While IS­ ABELLE foundered, the CERN project went from success to suc­ cess, achieving in its first years of operation the heady achievements which had been the privilege of the AGS physicists in the early sixties. However the spirit of the AGS physics teams remains indomita­ ble. After 25 years, the machine's physics potential is far from ex­ hausted, and a whole list of im­ provements is being pushed (see next story).

Plans for the future

Brookhaven is committed to the continuation of its robust high en­ ergy physics programme and to the initiation of a comprehensive fixed target and colliding beam programme for high energy (rela- tivistic) heavy ions. These initia-

CERN Courier, July/August 1985 235 tives result from the work of the and detector upgrades. BELLE project. As well as building AGS II Task Force (see June 1984 The other string to Brookha­ the RHIC itself, the AGS would issue, page 194) and other com­ ven's bow is heavy ions. Last have to be adapted for its new mittees. year, work got underway to allow role as the RHIC injector. The immediate particle physics heavy ions to be transferred from However the particle physics plans centre on improvements to the 16 MV tandem Van de Graaff content of the AGS programme is the 25-year old AGS - raising pro­ to the AGS (see December 1984 seen as continuing 'far beyond' ton beam intensities up to 5 x issue, page 433). As well as the the planned advent of the RHIC. 1013 particles per pulse, reliabili­ new transfer beamline, this re­ The AGS is tKe world's richest ties from 75 to 95 per cent, and quires modifications to existing source of kaons, and a pro­ beam duty factors from 25 to 45 beamlines and detectors, as well gramme of kaon physics would per cent; building a new booster as to the AGS itself. Ten weeks of include looking for rare decays to injector; improving beamlines and heavy ion running per year are fo­ test current ideas. Investigations detectors, and capitalizing on the reseen. of CP (charge conjugation/parity) spin physics capabilities which Subsequently, the new AGS violation, seen only in the neutral opened last year (see October booster could be adapted for kaon system, are vital if this long­ 1984 issue, page 328). heavy ion work, while further standing physics mystery is to be After this, a stretcher ring is en­ modifications could allow a wider finally understood. visaged to increase duty factors to range of heavy ions (up to atomic Other AGS particle physics ob­ 90 per cent or more, and power mass 200) to be handled. jectives include the neutrino sec­ supply and radiofrequency im­ For the 1990s, the big Relativis­ tor, where question marks still provements to push intensities up ts Heavy Ion Collider (RHIC) could loom as large as ever, spectros­ towards 1014 protons per pulse, be constructed in the tunnel origi­ copy in the 1 - 3 GeV region, together with further beamline nally made for the defunct ISA- where important new information could yet be obtained, and the study of hypernuclei (nuclei with one or more nucleons replaced by heavier particles) to provide an additional lever on particle inter­ actions. With polarized beams available in the AGS, the whole gamut of spin physics opens up. In addition, a new muon storage ring could be built to make even more precise measurements of the anomalous magnetic moment of the muon (see September 1984 issue, page 274).

Well-wishers crowd the experimental area at the AGS 25th anniversary party. (Photos Brookhaven)

236 CERN Courier, July/August 1985 Around the Laboratories

The UA2 experiment at CERN's proton- antiproton Collider - big companion for a series of smaller studies.

(Photo CERN 84.9.81)

CERN Two more Collider experiments The unique physics conditions provided by the SPS proton- antiproton Collider (see also page 229) are explored by experiments jiounted in the two large underground areas where the beams of protons and antiprotons are brought together. In one underground site sits the mighty UA1 detector, described as the most complicated piece of electronics in the world. The other is the home of the UA2 detector which complemented UA1 in the famous hunt for the W and Z particles (see November 1983 issue, page 370). In this second underground area, UA2 alternates with the UA5 visual detector which provides a fast survey of new collision conditions (see May install silicon/lead sandwich the same behaviour also occurs at issue, page 131). detectors in UA4's 'Roman Pots' to small angles. (The UA6 experiment at the detect the photons coming from After UA7 completes its running Collider works in a different way, the decay of neutral pions which this year, a new experiment, UA8, providing its own protons in the emerge from the proton- by a Los Angeles (UCLA) group form of a jet of hydrogen gas antiproton collisions close to the will install a new 'mini-drift' wire which squirts across the path of collision axis. chamber system in the Roman the circulating antiprotons - see UA1 and UA5 have revealed pots vacated by UA7. The UA8 April issue, page 102.) interesting suggestions of new team will look at the special In the same underground area behaviour in the numbers of 'diffractive' reactions which as the large UA2 apparatus is charged particles emerging from produce a fast forward proton (or another experiment - UA4 the collisions. These suggestions antiproton) together with large (Amsterdam/CERN/Genoa/Naples/ are interpreted by some as hints transverse energy which may be Pisa) - which studies elastic of the onset at SPS Collider in the form of 'jets'. The fast scattering, when the colliding protons and antiprotons 'bounce' energies of a long-awaited change forward particle will be detected in off each other like billiard balls of phase when matter containing the wire chamber system, as was (see October 1984 issue, page particles 'boils', producing matter done by UA4, while the transverse 336). containing quarks and gluons (see, energy will be picked up by Its initial aims accomplished, for example, the article by W. courtesy of UA2's large detector. UA4 will serve as a springboard Willis in the January/February The fast forward particle most for UA7 - a brief new study this 1982 issue, page 179). Clues have likely contains the three valence fall by a Naples/Japan group of been seen with particles coming quarks (antiquarks) of the beam neutral pions produced along the off at large angles to the collision proton (antiproton). Therefore, the collision axis. The UA7 team will axis, and it is important to check if particles with transverse energy

CERN Courier, July/August 1985 237

The first of the 416 9 metre-long bending magnets for the 30 Ge V electron ring of the HERA electron-proton collider being assembled at the German DESY Laboratory.

(Photo DESY)

9-metre bending magnets for the performance is limited by the DESY electron ring was assembled at beam-beam interaction in the ring. HERA's electron ring DESY. These magnets will supply The CESR ring at Cornell was a field of 0.1849 Tesla, fed by a designed for 8 GeV beam energy, \A/ork started in May on the tunnel single aluminium conductor 10 cm but the physics programme has for the new HERA electron-proton square, running all round the 6.4 concentrated on the 5 GeV/beam collider (see June issue, page 179), km ring. The bending magnets will region, with its rich upsilon and just as soon as each tunnel be included in 12-metre modules, physics. To overcome the limit section is complete, installation including also a quadrupole, one imposed by beam-beam will start of components for the 30 or two sextupoles and the interaction, more bunches of GeV electron storage ring. Work correction magnets, all on a single colliding particles can be stored, for the 820 GeV proton ring will support. which boosts the luminosity get underway later. provided extra collision points can Work on electron ring components is thus well be avoided. Electrostatic separator advanced. First deliveries of the CORNELL elements are ideal for this 496 quadrupole magnets and 632 Multi-bunch purpose. sextupoles should arrive at DESY Multiple bunch running was in September and October operation implemented in CESR during the respectively. At its peak energy, the luminosity summer of 1983, and became While the first 9 metre-long coil (collision rate) of an electron- standard practice from October of for the 'hybrid' superconducting positron storage ring is limited by that year. Beams are electro­ magnets for the proton ring was the current which can be stored statically separated in the being prepared for its cryostat at using the available radiofrequency horizontal plane on either side of Brown Boveri, the first of the 416 power. Below the peak energy. the interaction region. The

CERN Courier, July/August 1985 239 Plan view (not to scale) of multi-bunch operation as used in the CESR electron- positron collider at Cornell. Approximate bunch-encounter locations are indicated (solid bunches), with subsequent encounters at alternate points shown dotted. At the two interaction points for experiments (IP), the orbits coincide.

resultant 'pretzels' are phased so that the unwanted collisions coincide with maximum separation. With CESR, it is possible to run with up to seven bunches. During the first week of seven-bunch running at the end of last year, peak luminosities attained 3.6 x 1031 cm-2 s_1 per interaction region and integrated luminosities of 1.4 inverse picobarns per day were recorded. This required total beam currents above 160 mA, calling for significantly more r.f. power and leading to increased higher order mode heating. In early January, the demands of such currents on the r.f. system resulted in the failure of the cavity main power window. Although seven-bunch running has been temporarily halted pending improvements to the window, attaining such performance levels so quickly bodes well. During 18 months of multiple bunch running, initially with three bunches and then with the maximum seven, the major limitations have been identified. These come from accelerator optics and the effects of field errors, the r.f. cavity problems mentioned previously, and new demands on the detectors. In seven bunch running, the CLEO and CUSB detectors in the CESR ring have had to learn to trigger on bunch crossings only 365 nanoseconds apart. To handle this, new electronics have been designed and installed. In addition, the higher stored current has generally led to larger

Boyce McDaniel (left) and Karl Berkelman at the West pole of the CLEO experiment in the CESR ring. On 1 July, Berkelman took over from McDaniel as Director of Cornell's Newman Laboratory of Nuclear Studies.

240 CERN Courier, July/August 1985 People and things

backgrounds from synchrotron Future of CERN radiation and degraded beam particles. After careful study, these Under the chairmanship of Carlo Heavy neutrino? backgrounds have been minimized Rubbia, a 'Working Group on the by judiciously placed masks. Scientific and Technological Long- A big question mark still Looking further ahead, other term Future of CERN' has been set looms over the mass of the improvement projects should push up 'to explore various options for neutrino. Is this particle truly the luminosity to twice its present the long-term future of CERN, multi-bunch level. The first is to taking into account existing massless, mQving at the modify the injection system to facilities (infrastructures), speed of light, or has it some provide more reliable injection. emphasizing respective pros and small mass? For some time, The second is to install rare-earth/ cons; in working out these bench-top experiments in cobalt permanent quadrupole options, realistic boundary Moscow and elsewhere magnets close to the interaction conditions concerning financial studying beta decay have points to squeeze the colliding and manpower limitations should been suggesting that the beams closer together. These be taken into account.' Members electron-type neutrino weighs projects should be completed in of the Group are Giorgio Brianti somewhere in the region time for the arrival of the CLEO II (CERN), Pierre Darriulat (CERN), from 20 to 45 eV. detector (see April issue, page Gosta Ekspong (Stockholm), Carlo One sensitive test for 106). Rubbia (Chairman), Abdus Salam (London and Trieste), Samuel C. neutrino mass effects is the Ting (MIT), Simon van der Meer shape of the electron Change at the top (CERN), and Gus Voss (DESY). emission spectrum measured ECFA Chairman J. S act on will in beta decay. The detailed Boyce McDaniel stepped down as attend the meetings of the Group shape of the spectrum at the Director of Cornell's Floyd R. as an observer. The first meeting high energy end is governed Newman Laboratory of Nuclear took place on 5 June. by the mass of the electron- Studies on 1 July. His 18 year type neutrino. In a recently period as Director included both published result, John Jhhe 12 GeV electron synchrotron Simpson of the University of and the CESR electron-positron Gue/ph, Ontario, Canada, collider. While on leave from reports instead a distortion at Cornell in 1972, he served as head the low energy end of the of the Accelerator Division at beta decay spectrum of Fermilab during the tritium. Simpson, who has commissioning of the (then) 400 been studying tritium decay GeV accelerator. McDaniel is a for four years, interprets this member of ICFA (International Committee for Future as being due to a heavy (17.1 Accelerators), and is chairman of keV) neutrino. the Board of Overseers for the US Such a mass, a/though very Superconducting Super Collider light compared to other (SSC) project. He continues as particles (the lightweight Cornell Professor of Physics. electron is 511 keV), is New Cornell director is physicist unparallelled in neutrino Karl Berkelman. circles, and will be sure to set the theorists thinking.

Carlo Rubbia - looking at the long-term future of CERN.

CERN Courier, July/August 1985 241 Constant Tieche ATLAS at Argonne

Constant Tieche, retired head of ATLAS, short for Argonne Tandem CERN Finance and architect of Linear Accelerator System and the much of CERN's financial world's first superconducting administration, died on 27 May. heavy ion accelerator, was dedicated at the US Argonne National Laboratory on 3 June. Mervyn Hine retires The new linac boosts the energies of particles emerging from a Mervyn Hine, one of CERN's tandem Van de Graaff and founder members, retired at the provides a useful extension to the end of May. He came to the range of nuclear physics studies at Laboratory, together with the late Argonne. Similar machines are John Adams, in 1953 and played a under construction at Florida State leading role in the design, and Kansas State Universities. construction and commissioning of the 28 GeV Proton Synchrotron. On completion of the machine, French Academy of Sciences he began a ten-year period of major responsibility in the CERN Detector specialist Georges hierarchy working with Directors Charpak of CERN was recently General Adams, Weisskopf, elected a member of the Gregory and Jentschke. Viki prestigious French Academy of Weisskopf, in particular, paid Sciences. tribute to Hine as being the powerhouse behind the work of the CERN management at that time. He has contributed to accelerator development, to project presentations, to establishing financial procedures and to promoting developments in the Laboratory infrastructure (like the use of big computers, networks, high speed data links and office automation). His thinking and his forward vision have helped CERN to be ready when 'the future' arrived. Mervyn Hine is one of the pioneers who created CERN and who helped forge its particular character from which the Laboratory is now reaping the benefit.

Mervyn Hine

242 CERN Courier, July/August 1985 The nuclear physics section of NIKHEF, the Netherlands' Na­ European Organization for Nuclear Research tional Institute for Nuclear and European Laboratory for Particle Physics High-Energy Physics, has open­ Organisation Europeenne pour la Recherche Nucleaire ings in the PIMU group for Laboratoire Europeen pour la Physique des Particuies TWO EXPERIMENTAL PHYSICISTS The Experimental Physics Division intends to make an at the postdoc level, who are interested to participate in the appointment to the position of a research of the group on pion absorption in nuclei and on pion charge exchange in pionic atoms. The experiments are performed at the pion/muon facility in Amsterdam and in some cases abroad. PHYSICIST Several years of research experience in nuclear or (inter­ in experimental particle physics research. Candidates mediate energy) particle physics are required, while a strong are expected to have an excellent record of successful background in particle detection techniques and/or data pro­ work in this field, and to have the ability to provide cessing (hardware/software) is desirable. leadership. The appointment will be made for a fixed term, and may subsequently become permanent. The duration of one contract is two years. For the other one it is one year with a possibility of one year prolongation. The The holder will play an important role in all aspects appointment will be with the Foundation for Fundamental of the conception and design of experiments, and of Research on Matter (FOM). the construction and operation of detectors, and the development of on-line and off-line software and the Information can be obtained from Dr. R. van Dantzig, tel. (020) analysis of data. 5920120 or 5922008. Please send letters of application, including the names Candidates are invited to apply within two weeks after ap­ of three referees, list of publications, a brief curriculum pearance of this advertisement, while enclosing a curriculum vitae and a brief description of research interests, to vitae, also mentioning performed research and names of ref­ the erees, to Leader of the Experimental Physics Prof. Dr. G. van Middelkoop, Division, Scientific Director of NIKHEF, CERN, 1211 Geneva 23, Switzerland section K, Postbox 41882, quoting reference EP/RE, before 5.8.85. 1009 DB Amsterdam, Netherlands.

DEPUTY, DIRECTOR, GENERAL SCIENCES Salary Open Duties: Reporting to the Laboratory Director, the Deputy Di­ rector for General Sciences provides overall direction for Lab­ oratory divisions in high energy physics, nuclear physics, accelerator physics, and fusion research. Major responsibilities RESEARCH SCIENTIST POSITION IN EXPERIMENTAL include management oversight of these divisions, coordination of interdivisional programs and activities, establishment and NUCLEAR PHYSICS AT INDIANA UNIVERSITY implementation of goals consistent with the Laboratory's mis­ The Department of Physics at Indiana University invites applications sion, interaction with policy and advisory committees to ensure for a project tenure-track position in experimental nuclear physics, to the highest quality of scientific achievement, and management start in Fall, 1985, or early 1986, at the Indiana University Cyclotron liaison with the University of California, the U.S. Department Facility (IUCF). IUCF is a national user facility which provides inter­ of Energy, and other external agencies. mediate-energy light-ion beams affording excellent opportunities for Requirements: A distinguished record of scientific achievement forefront experimental research, which is supported and comple­ and proven leadership in managing interdisciplinary programs mented by the Nuclear Theory Center located in the cyclotron labo­ in fields such as high energy physics, nuclear physics, accel­ ratory. Upon completion of the electron cooled proton storage ring erator physics, or fusion research. Proven success in interacting now under construction, beams of unprecedented quality will be avail­ with academic institutions, scientific laboratories, private in­ dustry, and the federal government (especially the U.S. De­ able for precision nuclear research and the application of novel ex­ partment of Energy). Must have a Ph.D. in the physical sciences perimental techniques. The position of Research Scientist comprises

or equivalent experience. Requires strong management skills a 3-rank system at Indiana which is equivalent in structure and pro: in areas of decision-making, problem-solving, interpersonal motion criteria (with the exception of teaching duties) to the regular communications, staffing, funding, and facilities planning and faculty ranks. Although opportunity for part-time teaching exists, the utilization. "Position is subject to the financial disclosure re­ primary emphasis is upon research. Project tenure, when conferred, quirements of the California Political Reform Act of 1974." is with respect to the IUCF contract. Applicants must have a Ph.D., at Please submit two copies of resume including salary history least one year of post-doctoral experience, and should have dem­ and names and addresses of references to: onstrated outstanding potential to lead a vigorous independent re­ Chairman, Search Committee search program. Appointment at the Assistant Scientist level is LAWRENCE BERKELEY LABORATORY, anticipated, but appointment at higher rank will be considered for Employment Office, One Cyclotron Road, Building 90, Room 1012, Berkeley, CA 94720. appropriate candidates. Salary will be commensurate with qualifica­ Refer to Job #B/3425. tions, experience, and rank. Applicants should submit a curriculum Resumes must be received in the Employment Office by vitae, publication list, copies of recent publications, and arrange for September 1, 1985, 5:00 p.m. three letters of recommendation to be sent to: Dr. W.W. Jacobs An Equal Opportunity Employer MIFIH. Indiana University Cyclotron Facility 2401 Milo B. Sampson Lane LAWRENCE Bloomington, Indiana, USA 47405 LB BERKELEY as soon as possible, before the closing date of September 15, 1985. LABORATORY Indiana University is an equal opportunity/affirmative action employer.

CERN Courier, July/August 1985 243 EXPERIMENTAL HEAVY-ION NUCLEAR UNIVERSITY OF OXFORD PHYSICS RESEARCH POSITION AT LAWRENCE BERKELEY LABORATORY The Lawrence Berkeley Laboratory's Nuclear Service Di­ Department of Nuclear Physics vision has an opening for a Staff Scientist 2 to participate in the Dilepton Spectrometer (DLS) Project at the Bevalac. Appointment of This is a three year appointment with the possibility of conversion to career status. Research Officer Initial responsibilities involve the design and testing of the DLS electronic detection system, particularly in the drift The department will shortly appoint a Research Officer in chambers used for tracking leptons. After the construction phase, emphasis will shift to the experimental study of the Particle Physics. Whilst mainly a research appointment, the dilepton signal in p-nucleus and nucleus-nucleus collisions appointee will be required to undertake seventy-two hours a at the Bevalac, including all aspects of data-taking and data year of laboratory demonstrating and he/she will be encour­ analysis. aged to give graduate lectures. The research programme of The successful candidate must have a PhD in nuclear or the experimental particle physics group includes the Soudan particle physics as well as research experience in this area II search for proton decay, a major contribution to the DELPHI as evidenced by a record of recent publications, with ex­ detector for LEP (CERN), preparation for an experiment at tensive background using detectors, computers and elec­ HERA (DESY), and development of an indium detector for tronic equipment.

solar neutrinos. Applicants are requested to submit a curriculum vitae, list of publications and the names of at least three referees to: The appointment will be for three years with possible exten­ sion to five years. Salary will be on the lecturer scale £7520 Dr. Janis M. Dairiki, c/o Employment Office, - £15 390 (under review). Mail Stop 90-1042, LAWRENCE BERKELEY LABORATORY, Applications with the names and addresses of two referees Berkeley, CA 94720 should be sent to as early as possible. Refer to Job #A/3407.

Mr. M.S. Gautrey, Lawrence Berkeley Laboratory is an Equal Opportunity Department of Nuclear Physics, Affirmative Action Employer MIFIH. Keble Road, Oxford | LAWRENCE from whom further particulars may be obtained. BERKELEY The closing date is September 5 1985. LABORATORY

DIRECTOR OF THE INDIANA UNIVERSITY CYCLOTRON FACILITY We have positions open for: ir DESIGN ENGINEERS Applications are invited for the directorship of the Indiana University Cyclotron Facility (IUCF). IUCF is a major and ^ SALES ENGINEERS growing national users' facility for intermediate-energy nu­ ^ MARKETING DIRECTOR clear science with light ion beams. We seek a distinguished nuclear scientist to provide scientific leadership for the lab­ If you are presently working in a laboratory, university, oratory and its program. The director will serve a five-year or research environment and have knowledge of CAMAC term starting in the summer of 1986 and will receive a tenured or FASTBUS, you are of particular interest to us. KSC full professorship in the Department of Physics. The five-year uses the CAMAC and FASTBUS standards in designing term of the directorship will see the start of experimental and manufacturing computer-based data acquisition work with a new electron-cooling storage ring and the de­ and control systems for the scientific, aerospace/defense, velopment of plans for the future growth of the facility. Salary and industrial markets. will be commensurate with experience and qualifications. When you join KSC you will find yourself in a friendly, Applications with a complete resume, including the names stimulating, and creative environment. If you have the of four references, and nominations should be sent as soon background knowledge, we will help you acquire the training you might need to design, market, or sell KSC's as possible, but not later than Nov. 1, 1985, to products. Professor S. E. Vigdor, We offer you an excellent salary/benefits package. Chairman, Search and Screen Committee, Please send your resume in confidence to: Research and Graduate Development Bryan Hall 104, Indiana University, Laurie Pike Administrative Vice President Bloomington, Indiana 47405. KineticSystems Corporation 11 Maryknoll Drive Indiana University is an Affirmative Action/Equal Op­ Lockport, IL 60441 portunity Employer and encourages applications from women and minority candidates. An Equal Opportunity Employer (M/H/F)

244 CERN Courier, July/August 1985

2" Diameter Subnanosecond PUT

Subnanosecond time response (RT = 0.7 ns, TTS = 0,37 ns), 8-stage For scintillation counting and high energy physics experiments

The R2083 is a 2-inch diameter, 8-stage, head-on type photomultiplier tube developed specially for pulse counting applications. It features subnanosecond rise time, small transit time spread and high pulse linearity. The anode output signal is derived through a coaxial connector to preserve good signal quality.

Call or write for Data Sheets.

HAMAMATSU CORPORATION • 420 SOUTH AVENUE • MIDDLESEX, NEW JERSEY 08846 • PHONE:(201) 469-6640 International Offices in Major Countries of Europe and Asia.

CERN Courier, July/August 1985 249

CRYSTAL BALLS? XP3462!

The unique answer to crystal ball tr =3 ns, anode pulse rise time for delta-function light pulse 57 requirements. Developed for KfK's RE = 10% for Co and 3" x 3" Nal (Tl) scintillator 6 neutrino experiment, G = 10 at1500V the XP3462 offers a combination of rise Pulse linearity within 2% up to 100 mA. time and energy resolution unequalled by other3"PMTs. Plastic ball photo courtesy of LBL/GSI We've set the standard for over 20 years Philips Electronic Components and Materials Division, 5600 MD Eindhoven, The Netherlands. Telex 35000 phtc nl In the U.S.A.: Amperex Electronics Corporation, Hicksville NY 11802, (516) 931 -6200

Electronic components and materials Increase data network availability with the DNE Data Network Diagnostics System Even medium-sized data net­ * Memory for back-up confi­ works have problems with mo­ gurations - if there's a fault they dem cabinets that are overrun can be implemented immedi­ with cables. If there's a fault no ately using a single command one knows where to connect or We give our customers com­ loop-in test gear. How can one plete systems not just hard­ avoid interrupting the wrong ware. Send off for a free DNE line? All these difficulties are colour brochure. eliminated if you use the DNE Data Network Diagnostics Sys­ I >^ tem by Wandel&Goltermann. Information Coupon The DNE has the right inter­ faces, V.24/V.28 and X.20/X.21, I would like so there will be no problems • The DNE colour brochure * with interface compatibility • Your data measurement § technology product guide w later on. Our DNEs can be operated manually or remote- Name controlled via a VDU. Company The DNE has the following features: Street * 'Tidies up" data lines Town * Central interface monitoring, Tel alarm facilities, documentation * An analyser can be con­ nected without affecting data Wandel & Goltermannann (Schweiz) AG traffic Postfach 254 * Switching and patching facil­ CH-3000 Bern 25 ities Tel. (031)42.66.44 Telex 32112wagoch

254 CERN Courier, July/August 1985 12.002 E

Sandwich-type semi-chamber for CERN experiment UA.1 composite construction type manufacture.

Please request detailed infor­ mation. Mr H. Mauch will be glad to advise you personally.

We offer a range that is based on 25 years' experience and know how through successful collaboration with field specia­ lists. Stesalit AG Kunststoffwerk

We provide easily built-in CH-4249 Zullwil/SO o3 safety in Know-how. Telefon 061/800601, Telex 63182

CERN Courier, July/August 1985 255

CERN Courier, July/August 1985 257

31

The world's best power tubes are used in the world's most important scientific programs. Since 1971, when Varian EIMAC Oakridge National Laboratory • Group sales office. Call or write introduced the one megawatt X- Princeton Plasma Physics Labo­ today. 2159/8974, we have been the ratory • TRIUMF Laboratory Varian EIMAC world leader in design and man­ (University of British Columbia) 301 Industrial Way ufacture of high power tubes for • GSI Darmstadt (FRG) • Culham San Carlos, CA 94070 scientific and communcation Laboratory (England) « CEA 415 • 592-1221 applications. Fountenay-au-Rose (France) • Textor-KFA Julich (FRG) • GA VARIAN AG Among the many users, of' Steinhauserstrasse Technology (Doublet-3). EIMAC tubes in high technology CH-6300 Zug, Switzerland fusion research, particle accel­ Power tubes developed and Tel: (042) 23 25 75 eration and other state-of-the- manufactured by Varian EIMAC Telex: 868-841 art investigations are: used in the facilities mentioned • European Organizations for include the 8973, 8974, X-2062K/ Nuclear Research (CERN) • 9009 and Y676A/9013. These Fermi National Accelerator Lab­ tube types will be joined by oth­ oratory • Stanford Linear Accel­ ers in development to meet new erator Center « Lawrence program requirements. Berkeley Laboratory • Los Ala­ More information is available mos National Laboratory from Varian EIMAC. Or the near­ (LAMPF and FMIT programs) • est Varian Electron Device varian

260 CERN Courier, July/August 1985