DOCSLIB.ORG

Fast-Neutron Tomography Using a Mobile Neutron Generator for Assessment of Steam-Water Distributions in Two-Phase Flows

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Fast-Neutron Tomography Using a Mobile Neutron Generator for Assessment of Steam-Water Distributions in Two-Phase Flows Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1146 Fast-neutron tomography using a mobile neutron generator for assessment of steam-water distributions in two-phase flows PETER ANDERSSON ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-554-8947-2 UPPSALA urn:nbn:se:uu:diva-222459 2014 Dissertation presented at Uppsala University to be publicly examined in Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, Wednesday, 4 June 2014 at 09:15 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Bernhard Ludewigt (UC Berkeley). Abstract Andersson, P. 2014. Fast-Neutron Tomography using a Mobile Neutron Generator for Assessment of Steam-Water Distributions in Two-Phase Flows. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1146. 70 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-8947-2. This thesis describes the measurement technique of fast-neutron tomography for assessing spatial distributions of steam and water in two-phase flows. This so-called void distribution is of importance both for safe operation and for efficient use of the fuel in light water reactors, which compose the majority of the world’s commercial nuclear reactors. The technique is aimed for usage at thermal-hydraulic test loops, where heated two-phase flows are being investigated under reactor-relevant conditions. By deploying portable neutron generators in transmission tomography, the technique becomes applicable to stationary objects, such as thermal-hydraulic test loops. Fast neutrons have the advantage of high transmission through metallic structures while simultaneously being relatively sensitive to the water/void content. However, there are also challenges, such as the relatively low yield of commercially available fast-neutron generators, the tendency of fast neutrons to scatter in the interactions with materials and the relatively low efficiency encountered in fast-neutron detection. The thesis describes the design of a prototype instrument, FANTOM, which has been assembled and demonstrated. The main design parameters have been optimized to achieve maximal signal count rate in the detector elements, while simultaneously reaching an image unsharpness of ≤0.5 mm. Radiographic projections recorded with the assembled instrument are presented, and the performance parameters of FANTOM are deduced. Furthermore, tomographic reconstruction methods for axially symmetric objects, which is relevant for some test loops, have been developed and demonstrated on measured data from three test objects. The attenuation distribution was reconstructed with a radial resolution of 0.5 mm and an RMS error of 0.02 cm-1, based on data recorded using an effective measurement time of 3.5 hours per object. For a thermal-hydraulic test loop, this can give a useful indication of the flow mode, but further development is desired to improve the precision of the measurements. Instrument upgrades are foreseen by introducing a more powerful neutron generator and by adding detector elements, speeding up the data collection by several orders of magnitude and allowing for higher precision data. The requirements and performance of an instrument for assessment of arbitrary non-symmetric test loops is discussed, based on simulations. Keywords: Void distribution, neutron tomography, plastic scintillator, transmission measurements, neutron detection Peter Andersson, Department of Physics and Astronomy, Applied Nuclear Physics, Box 516, Uppsala University, SE-751 20 Uppsala, Sweden. © Peter Andersson 2014 ISSN 1651-6214 ISBN 978-91-554-8947-2 urn:nbn:se:uu:diva-222459 (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-222459) List of Papers This thesis is based on the following papers, which are referred to in the text by their Roman numerals. Reprints were made with permission from the respective publishers. I Andersson, P., Sjöstrand, H., Jacobsson Svärd, S 11) Ef- fects of proton escape on detection efficiency in thin scintillator elements and its consequences for optimization of fast-neutron imaging. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associ- ated Equipment, -116. This paper describes the energy deposition distribution in thin plate-shaped plastic scintillators when exposed to DQG MeV neutrons. My contribution: I created the Monte Carlo scripts, performed the simulations and the analysis. I wrote the major part of the paper. II Andersson, P., Andersson Sundén, E., Jacobsson Svärd, S., 6M|VWUDQG + Correction for dynamic bias error in transmission measurements of void fraction. Review of Scien- tific Instruments9ROXPH This paper describes the systematic error in transmission meas- urements of void fraction in two-phase flows arising from the dynamic property of such systems. A correction procedure is suggested and demonstrated on artificial data. My contribution: I developed the method and performed the analysis. I wrote the major part of the paper. III Andersson, P., Valldor-Blücher, J., Andersson Sundén, E., Sjöstrand, H., Jacobsson-6YlUG6 ) Design and initial 1D radiography tests of the FANTOM mobile FAst-Neutron radi- ography and TOMography system. Accepted for publication, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. This paper describes the design optimization, the expected and experimentally determined performance of a portable fast- neutron radiography instrument. My contribution: I performed the optimization of the instrument design, assembled it and per- formed the measurements and the analysis. I wrote the major part of the paper. IV Andersson, P., Andersson Sundén, E., Sjöstrand, H., Jacob- sson-6YlUG6 Neutron tomography of axially symmet- ULFREMHFWXVLQJ0H9QHXWURQVIURPDSRUWDEOH neutron gen- erator. Submitted to Review of Scientific Instruments. In this paper tomographic reconstruction of axially symmetric objects using fast neutrons is demonstrated using five test ob- jects. My contribution: I developed the methods and the code used for the reconstruction and I performed the analysis. I wrote the major part of the paper. Additional papers by the author, not included in the thesis: Andersson P., Jacobsson-Svärd, S, Sjöstrand, H. 1Hu- tron tomography for void distribution measurements. ENC 2010 Transactions: Plant Operations. Rakopoulos V., Lantz M., Andersson P., Hjalmarsson A., Mat- tera A., Pomp S., Solders A., Valldor-Blücher J., Gorelov D., Penttilä H., Rinta-Antila S., Bedogni R., Bortot D., Esposito A., Gentile A., Passoth E., Prokofiev A. V., Introini M. V., Pola A., 7DUJHWWKLFNQHVVGHSHQGHQFHRIWKH S[Q QHXWURQHQHr- gy spectrum. EPJ Web of Conferences Mattera A., Andersson P., Hjalmarsson A., Lantz M., Pomp S., Rakopoulos V., Solders A., Valldor-Blücher J., Gorelov D., Penttilä H., Rinta-Antila S., Prokofiev A. V., Passoth E., Be- dogni R., Gentile A., Bortot D., Esposito A., Introini M. V., Po- la A., &KDUDFWHUL]DWLRQRID%( S[Q QHXWURQVRXUFHIRU fission yields measurments. arXiv:1304.0547 Contents 1. Introduction ........................................................................................... 9 Void distributions in light water reactors ............................................ 3. Transmission tomography ................................................................... 3.1. General principles ............................................................................. 6HWXSFRQILJXUDWLRQV .......................................................................... 3.3. Using neutrons as transmission probe ............................................... 17 ,QWHUDFWLRQVRIQHXWURQVZLWKPDWWHU .................................................. 19 5HFRQVWUXFWLRQDOJRULWKPV ................................................................. 19 3.6. Tomography of the two-phase flow .................................................. Components of a mobile setup for fast-neutron tomography .............. 1HXWURQJHQHUDWRUV ............................................................................ Collimators ........................................................................................ )DVW-neutron detectors ....................................................................... FANTOM, the FAst-Neutron TOMography system ........................... 7KHVHWXS ........................................................................................... 'DWDDFTXisition system ..................................................................... )$1720PRGHVRIRSHUDWLRQ .......................................................... ,QVWUXPHQWRSWLPL]DWLRQ .................................................................... 6. Experimental investigations ................................................................. 6.1. Measurements .................................................................................... 'DWDSURFHVVLQJ ................................................................................. 7. FANTOM results ................................................................................. 7.1. Radiographic imaging ....................................................................... 7RPRJUDSK\RQD[LDOO\V\PPHWULFREMHFWV ....................................... 8. Conclusions and discussion ................................................................. 8.1. A concept for neutron
Load more

Recommended publications
  • Three Dimensional Polarimetric Neutron Tomography of Magnetic
    www.nature.com/scientificreports OPEN Three Dimensional Polarimetric Neutron Tomography of Magnetic Fields Received: 25 April 2017 Morten Sales 1, Markus Strobl 2,3, Takenao Shinohara4, Anton Tremsin5, Luise Theil Kuhn 6, Accepted: 18 January 2018 William R. B. Lionheart7, Naeem M. Desai 7, Anders Bjorholm Dahl8 & Søren Schmidt 1 Published: xx xx xxxx Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the frst time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic feld strengths and directions unobtrusively and non- destructively with the potential to probe the interior of bulk samples which is not amenable otherwise. Using a pioneering polarimetric set-up for ToF neutron instrumentation in combination with a newly developed tailored reconstruction algorithm, the magnetic feld generated by a current carrying solenoid has been measured and reconstructed, thereby providing the proof-of-principle of a technique able to reveal hitherto unobtainable information on the magnetic felds in the bulk of materials and devices, due to a high degree of penetration into many materials, including metals, and the sensitivity of neutron polarisation to magnetic felds. The technique puts the potential of the ToF time structure of pulsed neutron sources to full use in order to optimise the recorded information quality and reduce measurement time. Te spin of a neutron passing through a magnetic feld will undergo an amount of precession proportional to the strength of the magnetic feld and the time spent by the neutron in the magnetic feld. Te time is proportional to the neutron wavelength, λ, and the path length through the magnetic feld, L.
    [Show full text]
  • ICANS XXI Dawn of High Power Neutron Sources and Science Applications
    Book of Abstracts ICANS XXI Dawn of high power neutron sources and science applications 29 Sep - 3 Oct 2014, JAPAN Ibaraki Prefectural Culture Center Update : 12 Oct. 2014 Best photography in 7th Oarai Town Photo Contest. WELCOME TO ICANS XXI ICANS (International Collaboration on Advanced Neutron Sources) is a network for scientists who are involved in developing pulsed neutron sources and accelerator based spallation neutron sources. Since 1st ICANS meetings was held in 1977 at Argonne National Laboratory in the day of dawn of spallation neutron technique, ICANS has been continuously held already 20 times somewhere in the world. Now we are extremely happy to announce that the ICANS, the 21st meeting, will be held at Mito hosted by J-PARC this autumn. We have a large number of topics to be discussed, there are twelve topics, such as futuristic idea of neutron source, rapid progress in facilities, integration issues in target-moderator-development, etc. The details can be found in the agenda. The meeting has a two layered structure, one is plenary session and another is workshop. Two of them are complementary and tightly cooperate each other. In the meeting we would like to enhance "workshop style", which is an original and traditional way of ICANS. Actually 2/3 of topics will be discussed in the workshop sessions. It also will be essentially organized/ lead by the workshop chairs. Plenary session shows overall issues in a relevant workshop, whose details should be talked/discussed in the workshop. The venue for the meeting is Mito city, where the 2nd Shogun Family lived for a long period of time during Edo era from 17th to 19th century, when the Tokugawa shogunate ruled the country.
    [Show full text]
  • Application of 3D Neutron Imaging and Tomography in Cultural Heritage Research
    F1-RC-1219.1 LIMITED DISTRIBUTION International Atomic Energy Agency Coordinated Research Project on Application of 3D Neutron Imaging and Tomography in Cultural Heritage Research Report of the first Research Co-ordination Meeting Vienna, Austria 07 - 11 May 2012 Reproduced by the IAEA Vienna, Austria, 2012 NOTE The material reproduced here has been supplied by the authors and has not been edited by the IAEA. The views expressed remain the responsibility of the named authors and do not necessarily reflect those of the government(s) of the designating Member State(s). In particular, neither the IAEA nor any other organization or body sponsoring the meeting can be held responsible for this material CONTENTS 1. FOREWORD .................................................................................................................... 1 2. EXECUTIVE SUMMARY ............................................................................................... 2 3. INTRODUCTION ............................................................................................................. 3 4. CRP OBJECTIVES ........................................................................................................... 4 4.1. Objectives of the CRP ............................................................................................ 4 4.2. Objectives of 1st RCM meeting ............................................................................. 4 4.3 Working groups: ....................................................................................................
    [Show full text]
  • Use of DD-108 Neutron Generator with ISU Sub-Critical Assembly
    From: Ramsey, Kevin To: Maxwell Daniels Cc: Campbell, Vivian; Font, Ossy; Yin, Xiaosong; Gonzalez, Hipolito; Johnson, Robert; Tripp, Christopher Subject: Use of DD-108 neutron generator with ISU sub-critical assembly Date: Thursday, July 20, 2017 3:46:00 PM We have evaluated your proposal to use a neutron generator to pulse your sub-critical assembly, and concluded that you may use the neutron generator under the current authorization in Materials License SNM-1373. Our finding that you may proceed without an amendment is based on the following understanding. If your understanding differs, please inform us. It is our understanding that you want to use the Adelphi Technology DD-108 Neutron Generator described at http://www.adelphitech.com/products/dd108.html. The technical brochure located at http://www.adelphitech.com/pdfs/DD108-9_generator_Flier_24-Nov- 14_A.PDF states that the device uses deuterium gas to produce 2.45 MeV neutrons. The NRC does not regulate the possession and use of deuterium, so there is no need to add the device to one of your NRC licenses. PLEASE NOTE – NRC regulates tritium and a license amendment would be needed to possess and use a tritium neutron generator. Our criticality safety evaluation concluded that using a neutron source will affect the fission rate, but will not affect the neutron multiplication or criticality analysis. From the description and pictures of the neutron generator, it appears that it would only contain a small amount of deuterium. As long as this is not permitted to come into physical contact with the SNM, there should be no issue.
    [Show full text]
  • A Novel Energy Resolved Neutron Imaging Detector Based On
    A novel energy resolved neutron imaging detector based on TPX3Cam for the CSNS Jianqing Yang1,2,3, Jianrong Zhou2,3,4*, Xingfen Jiang2,3,4, Jinhao Tan2,3,5, Lianjun Zhang2,3,5, Jianjin Zhou2,3, Xiaojuan Zhou2,3,Wenqin Yang2,3,4,Yuanguang Xia2,3, Jie Chen2,3, XinLi Sun1, Quanhu Zhang1**, Zhijia Sun2,3,4***, Yuanbo Chen2,3,4 1. Xi’an Research Institute of Hi-Tech, 710025, Xian,China. 2. Spallation Neutron Source Science Center, Dongguan, 523803, Guangdong, China; 3. State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China; 4. University of Chinese Academy of Sciences, Beijing 100049, China 5. Harbin Engineering University, Harbin, Heilongjiang, China, 150000 Abstract: The China Spallation Neutron Source (CSNS) operates in pulsed mode and has a high neutron flux. This provides opportunities for energy resolved neutron imaging by using the TOF (Time Of Flight) approach. An Energy resolved neutron imaging instrument (ERNI) is being built at the CSNS but significant challenges for the detector persist because it simultaneously requires a spatial resolution of less than 100 μm, as well as a microsecond-scale timing resolution. This study constructs a prototype of an energy resolved neutron imaging detector based on the fast optical camera, TPX3Cam coupled with an image intensifier. To evaluate its performance, a series of proof of principle experiments were performed in the BL20 at the CSNS to measure the spatial resolution and the neutron wavelength spectrum, and perform neutron imaging with sliced wavelengths and Bragg edge imaging of the steel sample.
    [Show full text]
  • Conceptual Design Report Jülich High
    General Allgemeines ual Design Report ual Design Report Concept Jülich High Brilliance Neutron Source Source Jülich High Brilliance Neutron 8 Conceptual Design Report Jülich High Brilliance Neutron Source (HBS) T. Brückel, T. Gutberlet (Eds.) J. Baggemann, S. Böhm, P. Doege, J. Fenske, M. Feygenson, A. Glavic, O. Holderer, S. Jaksch, M. Jentschel, S. Kleefisch, H. Kleines, J. Li, K. Lieutenant,P . Mastinu, E. Mauerhofer, O. Meusel, S. Pasini, H. Podlech, M. Rimmler, U. Rücker, T. Schrader, W. Schweika, M. Strobl, E. Vezhlev, J. Voigt, P. Zakalek, O. Zimmer Allgemeines / General Allgemeines / General Band / Volume 8 Band / Volume 8 ISBN 978-3-95806-501-7 ISBN 978-3-95806-501-7 T. Brückel, T. Gutberlet (Eds.) Gutberlet T. Brückel, T. Jülich High Brilliance Neutron Source (HBS) 1 100 mA proton ion source 2 70 MeV linear accelerator 5 3 Proton beam multiplexer system 5 4 Individual neutron target stations 4 5 Various instruments in the experimental halls 3 5 4 2 1 5 5 5 5 4 3 5 4 5 5 Schriften des Forschungszentrums Jülich Reihe Allgemeines / General Band / Volume 8 CONTENT I. Executive summary 7 II. Foreword 11 III. Rationale 13 1. Neutron provision 13 1.1 Reactor based fission neutron sources 14 1.2 Spallation neutron sources 15 1.3 Accelerator driven neutron sources 15 2. Neutron landscape 16 3. Baseline design 18 3.1 Comparison to existing sources 19 IV. Science case 21 1. Chemistry 24 2. Geoscience 25 3. Environment 26 4. Engineering 27 5. Information and quantum technologies 28 6. Nanotechnology 29 7. Energy technology 30 8.
    [Show full text]
  • How I Learned to Stop Worrying and Dismantle the Bomb New Approaches to Nuclear Warhead Verification
    HOW I LEARNED TO STOP WORRYING AND DISMANTLE THE BOMB NEW APPROACHES TO NUCLEAR WARHEAD VERIFICATION Alex Glaser,* Sébastien Philippe,* and Robert J. Goldston** *Princeton University **Princeton University and Princeton Plasma Physics Laboratory Duke University, January 19, 2017 Revision 1 CONSORTIUM FOR VERIFICATION TECHNOLOGY PNNL Oregon State MIT U Michigan INL Yale U Wisconsin Columbia Penn State Princeton and PPPL U Illinois LBNL LLNL Sandia NNSS Duke ORNL NC State LANL Sandia U Florida (not shown: U Hawaii) Five-year project, funded by U.S. DOE, 13 U.S. universities and 9 national labs, led by U-MICH Princeton participates in the research thrust on disarmament research (and leads the research thrust of the consortium on policy) A. Glaser, S. Philippe, R. Goldston, How I Learned to Stop Worrying and Dismantle the Bomb, Duke University, January 19, 2017 2 INTERNATIONAL PARTNERSHIP FOR NUCLEAR DISARMAMENT VERIFICATION Established in 2015; currently 26 participating countries Working Group One: “Monitoring and Verification Objectives” (chaired by Italy and the Netherlands) Working Group Two: “On-Site Inspections” (chaired by Australia and Poland) Working Group Three: “Technical Challenges and Solutions” (chaired by Sweden and the United States) www.state.gov/t/avc/ipndv A. Glaser, S. Philippe, R. Goldston, How I Learned to Stop Worrying and Dismantle the Bomb, Duke University, January 19, 2017 3 WHAT’S NEXT FOR NUCLEAR ARMS CONTROL? 2015 STATEMENT BY JAMES MATTIS “The nuclear stockpile must be tended to and fundamental questions must be asked and answered: • We must clearly establish the role of our nuclear weapons: do they serve solely to deter nuclear war? If so we should say so, and the resulting clarity will help to determine the number we need.
    [Show full text]
  • Radiological Safety Aspects of the Operation of Neutron Generators
    \ This publication is no longer valid Nuclear Safety Information Centre, B0655 Please see http://www-ns.iaea.org/standards/ OBSOLETE SAFETY SERIES No. 42 Radiological Safety Aspects of the Operation of Neutron Generators INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1 976 This publication is no longer valid Please see http://www-ns.iaea.org/standards/ This publication is no longer valid Please see http://www-ns.iaea.org/standards/ RADIOLOGICAL SAFETY ASPECTS OF THE OPERATION OF NEUTRON GENERATORS This publication is no longer valid Please see http://www-ns.iaea.org/standards/ The following States are Members of the International Atomic Energy Agency: AFGHANISTAN HOLY SEE PHILIPPINES ALBANIA HUNGARY POLAND ALGERIA ICELAND PORTUGAL A RG EN TIN A IN D IA QATAR AUSTRALIA INDONESIA REPUBLIC OF SOUTH VIETNAM AUSTRIA IRAN ROMANIA BANGLADESH IRAQ SAUDI ARABIA BELG IU M IRELAND SENEGAL BOLIVIAISRAEL SIERRA LEONE BRAZIL ITALY SINGAPORE BULGARIA IVORY COAST SOUTH AFRICA BURMA JAMAICA SPAIN BYELORUSSIAN SOVIET JAPAN SRI LANKA SOCIALIST REPUBLIC JORDANSUDAN CAMBODIA KENYA SWEDEN CANADA KOREA, REPUBLIC OF SWITZERLAND CHILE KUWAIT SYRIAN ARAB REPUBLIC COLOM BIA LEBANON THAILAND COSTA RICA LIBERIA TUNISIA CUBA LIBYAN ARAB REPUBLIC TURKEY CYPRUS LIECHTENSTEIN UGANDA CZECHOSLOVAKIA LUXEMBOURG UKRAINIAN SOVIET SOCIALIST DEMOCRATIC PEOPLE’S MADAGASCAR REPU BLIC REPUBLIC OF KOREA MALAYSIA UNION OF SOVIET SOCIALIST DENMARK MALI REPUBLICS DOMINICAN REPUBLIC MAURITIUS UNITED ARAB EMIRATES ECUADOR M EXICO UNITED KINGDOM OF GREAT EGYPT MONACO BRITAIN AND NORTHERN
    [Show full text]
  • The Hansen Letter
    The Hansen Letter Introduction by Howard Morland, November 2003: This seven-thousand-word letter by Chuck Hansen, dated August 27, 1979, delivered a coup de grace to the government=s case for censorship of my Progressive magazine article on the H- bomb. It is a bit odd that Senator Charles Percy of Illinois was the intended recipient of the letter. He was never involved in The Progressive case, nor was he Chuck Hansen=s senator. He did not, apparently, request such a communication, and after receiving it he did not subsequently play a role in The Progressive case. However, copies of the letter immediately began to circulate among all persons concerned with the case. Hansen=s reason for writing the letter is not entirely clear, except as a vehicle for outlining his theory about the H-bomb secret. As he states in the letter, AThese... are some of the ideas I believe are presented in the Morland article (I have not seen the article).@ The defense attorneys in The Progressive case regarded him as an ally, of sorts, but wanted no part of his call for the punishment of Edward Teller, Theodore Taylor, and George Rathjens for security violations. Nonetheless, the defense was preparing to argue in court that the widespread distribution of this Hansen letter should moot The Progressive case. The letter clearly outlines the three H-bomb principles at issue in the case: separation of stages, compression, and radiation coupling. However it introduces two obvious technical flaws. Hansen describes the use of two primaries, or fission triggers, one at either end of the fusion secondary, which would explode simultaneously to compress the fusion secondary between them.
    [Show full text]
  • Small Angle Scattering in Neutron Imaging—A Review
    Journal of Imaging Review Small Angle Scattering in Neutron Imaging—A Review Markus Strobl 1,2,*,†, Ralph P. Harti 1,†, Christian Grünzweig 1,†, Robin Woracek 3,† and Jeroen Plomp 4,† 1 Paul Scherrer Institut, PSI Aarebrücke, 5232 Villigen, Switzerland; [email protected] (R.P.H.); [email protected] (C.G.) 2 Niels Bohr Institute, University of Copenhagen, Copenhagen 1165, Denmark 3 European Spallation Source ERIC, 225 92 Lund, Sweden; [email protected] 4 Department of Radiation Science and Technology, Technical University Delft, 2628 Delft, The Netherlands; [email protected] * Correspondence: [email protected]; Tel.: +41-56-310-5941 † These authors contributed equally to this work. Received: 6 November 2017; Accepted: 8 December 2017; Published: 13 December 2017 Abstract: Conventional neutron imaging utilizes the beam attenuation caused by scattering and absorption through the materials constituting an object in order to investigate its macroscopic inner structure. Small angle scattering has basically no impact on such images under the geometrical conditions applied. Nevertheless, in recent years different experimental methods have been developed in neutron imaging, which enable to not only generate contrast based on neutrons scattered to very small angles, but to map and quantify small angle scattering with the spatial resolution of neutron imaging. This enables neutron imaging to access length scales which are not directly resolved in real space and to investigate bulk structures and processes spanning multiple length scales from centimeters to tens of nanometers. Keywords: neutron imaging; neutron scattering; small angle scattering; dark-field imaging 1. Introduction The largest and maybe also broadest length scales that are probed with neutrons are the domains of small angle neutron scattering (SANS) and imaging.
    [Show full text]
  • The Tokamak As a Neutron Source
    PREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76-CHO-3073 PPPL-2656 PPPL-2656 UC-420 THE TOKAMAK AS A NEUTRON SOURCE BY H.W. HENDEL AND D.L JASSBY November 1989 PMNCITON PLASMA PHYSICS LASOffATORY PRINCETON UNIVERSITY, PRINCETON, NEW JERSEY NOTICE Available from: National Technical Information Service U.S. Department of Commerce 5285 Port Royal Road Springfield. Virginia 22161 703-487-4650 Use the following price codes when ordering: Price: Printed Copy A04 Microfiche A01 THE TOKAMAK AS A NEUTRON SOURCE by H.W. Hendel and D.L. Jassby PPPL—2656 DE90 001821 Princeton Plasma Physics Laboratory Princeton University Princeton, N.J. 08543 ABSTRACT This paper describes the tokamak in its role as a neutron source, with emphasis on experimental results for D-D neutron production. The sections summarize tokamak operation, sources of fusion and non-fusion neutrons, principal nsutron detection methods and their calibration, neutron energy spectra and fluxes outside the tokamak plasma chamber, history of neutron production in tokamaks, neutron emission and fusion power gain from JET and TFTR (the largest present-day tokamaks), and D-T neutron production from burnup of D-D tritons. This paper also discusses the prospects for future tokamak neutron production and potential applications of tokamak neutron sources. DISCLAIMER This report was prepared as JH account or work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi­ bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or repre^r-s that its use would not infringe privately owned rights.
    [Show full text]
  • Use of Neutron Beams for Low and Medium Flux Research Reactors: Radiography and Materials Characterization
    IAEA-TECDOC-837 Use of neutron beams for low and medium flux research reactors: radiography and materials characterization Report Technicala of Committee meeting held in Vienna, 4-7 May 1993 INTERNATIONAL ATOMIC ENERGY AGENCY The originating Sectio f thino s publicatio IAEe th An i was: Physics Section International Atomic Energy Agency Wagramerstrasse 5 0 10 x P.OBo . A-1400 Vienna, Austria USE OF NEUTRON BEAMS FOR LOW AND MEDIUM FLUX RESEARCH REACTORS: RADIOGRAPH MATERIALD YAN S CHARACTERIZATION IAEA, VIENNA, 1995 IAEA-TECDOC-837 ISSN 1011-4289 ©IAEA, 1995 Printe IAEe th AustriAn i y d b a October 1995 FOREWORD Research reactors have been playing an important role in the development of scientific and technological infrastructure and in training of manpower for the introduction of nuclear power in many countries. Currently, there are 284 operational research reactors in the world, includindevelopin9 3 n i 8 g8 g countries numbee th ; f reactoro r developinn si g countries si increasin s morga e countries embar programmen ko nuclean i s r scienc technologyd ean . However, full utilization of these facilities for fundamental and applied research has seldom been achieved. In particular, the utilization of beam ports has been quite low. Neutron beam based researce mosth f t o s regardeimportani he on s a d t research programme carriee sb than dca t out, eve mediud nan witw mhlo flux reactors range Th .f eo activities possibl n thii e s wido s fiel s e i d s generall i tha t i t y feasibl o defint D e R& e programmes suite specifio dt c need conditionsd san therefors i t I .
    [Show full text]