Keyword: neutron
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MOPEA032 Installation Status of Deuteron Injector of IFMIF Prototype Accelerator in Japan rfq, emittance, alignment, simulation 148
 
  • H. Shidara, J. Knaster
    IFMIF/EVEDA, Rokkasho, Japan
  • D. Bogard, N. Chauvin, P. Girardot, R. Gobin, F. Harrault, D. Loiseau, P.A.P. Nghiem, A. Roger, F. Senée
    CEA/DSM/IRFU, France
  • L. Semeraro
    F4E, Barcelona, Spain
  
  The International Fusion Materials Irradiation Facility (IFMIF) will generate a neutron irradiation field with the spectrum simulating the fusion D-T neutrons (14 MeV) to qualify suitable materials for fusion power plants. The IFMIF accelerator facility provides two CW / 40 MeV / 125 mA deuteron beams to the IFMIF Lithium target facility. In the Engineering Validation and Engineering Design Activities phase, the concept of IFMIF is validated with a single CW / 9 MeV / 125 mA deuteron accelerator prototype under construction in JAEA/Rokkasho. The injector part has been designed, constructed and successfully tested by CEA/Saclay. The ECR ion source produces a deuteron beam of 140 mA at 100 keV. In spring 2013, the injector will be delivered and re-installed on the Rokkasho site. This paper will focus on the detailed plan of the injector’s re-assembly as well as on the re-commissioning. Further possible improvements are discussed in order to achieve reliable operation.  
 
MOPEA039 Beam Commissioning and Neutron Radiography on a High Current Deuteron RFQ rfq, cavity, target, ECR 163
 
  • Y.R. Lu, J. Chen, J.E. Chen, S.L. Gao, Z.Y. Guo, F.J. Jia, G. Liu, S.X. Peng, H.T. Ren, W.L. Xia, X.Q. Yan, K. Zhu
    PKU, Beijing, People's Republic of China
  • S.Q. Liu, S. Wang, J. Zhao, B.Y. Zou
    State Key Laboratory of Nuclear Physics and Technology, Beijing, Haidian District, People's Republic of China
  
  Funding: Supported by NSFC 11079001 and Peking University
The high current deuteron RFQ has been developed and widely used in many projects, especially for accelerator based neutron source and its application. This paper reviews not only the recent developments in the world wide, also presents the beam dynamics, structure design ,RF full power test, beam commissioning of PKUNIFTY, which is consisted of a high current very compact ECR source, a 201.5MHz four-rod deuteron RFQ, thicker beryllium target and its moderating, collimation and neutron radiography system. RF and beam commissioning with duty cycle of 4% show the RFQ inter-vane voltage reaches 70kV at about 240kW, the delivered deuteron peak beam current is about 12mA at 290kW with the beam transmission of about 60%. The improvement of transmission is going on. The initial neutron radiography commissioning has been carried out. The results will promote the future development of small accelerator based neutron source. 		 
 
MOPFI026 Thermal Simulations of a New Target Configuration for Production of Radioactive Nuclide target, simulation, radiation, ion 336
 
  • L.H. Chen, B.Q. Cui, Q.H. Huang, W. Jiang, R. Ma, Y.J. Ma, B. Tang
    CIAE, Beijing, People's Republic of China
  
  China Advanced Rare Ion-beam Facility (CARIF) based on China Advanced Research Reactor (CARR) has been proposed in order exploring the frontier of nuclear physics. A target with 5 g 235U is proposed in the project. The thermal neutron fission of 235U will produce radioactive nuclei and the great thermal load (~50 kW). The target of CARIF needs endure high temperature and thermal energy deposit. A new multi-targets configuration is proposed. It consists of several discrete targets instead of traditional single-target structure used in accelerator driven facility. Because there is more thermal radiation area in this configuration, thermal radiation capacity is enhanced, so the target can withstand higher thermal power. The temperature distribution of multi-targets was simulated with finite element code. The results show that the configuration of multi targets can effectively reduce the target temperature. From the perspective of target temperature distribution, the configuration could endure 50kW thermal deposit. It's possible to use 5 g 235U in CARIF for production of radioactive nuclide.  
 
MOPFI031 Progress on the Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source linac, electron, controls, dipole 351
 
  • Y.L. Chi, J. Cao, P. Chen, B. Deng, C.D. Deng, D.Y. He, X. He, M. Hou, X.C. Kong, Q. Le, X.P. Li, J. Liu, R.L. Liu, W.B. Liu, H.Z. Ma, G. Pei, S. Pei, H. Song, L. Wang, S.H. Wang, X. Wang, Q. Yang, J. Yue, J.B. Zhao, J.X. Zhao, Z.S. Zhou
    IHEP, Beijing, People's Republic of China
  • M.I. Ayzatskiy, I.M. Karnaukhov, V.A. Kushnir, V.V. Mytrochenko, A.Y. Zelinsky
    NSC/KIPT, Kharkov, Ukraine
  • Y. Gohar
    ANL, Argonne, USA
  
  IHEP, China is constructing a 100 MeV / 100 kW electron linac for NSC KIPT, Ukraine. This linac will be used as the driver of a neutron source based on a subcritical assembly. In 2012, the injector part of the linac was pre-installed as a testing facility in the experimental hall #2 of IHEP. The injector beam and key hardware testing results were satisfying. Recently, the injector testing facility was disassembled and all of the components for the whole linac have been shipped to Ukraine from China by ocean shipping. The installation of the whole machine in KIPT will be started in June. The progress on the construction are reported, injector beam and key hardware testing results are presented.  
 
MOPFI070 Spallation is not the only Fruit: Low Energy Fusion as a Source of Neutrons target, proton, simulation, radiation 443
 
  • S.C.P. Albright, R. Seviour
    University of Huddersfield, Huddersfield, United Kingdom
  
  Commercially there is a growing interest in applications of neutrons. Currently the majority of neutron sources are based at research institutions from either reactors or spallation sources. Smaller portable sources contain either fissile isotope or sealed fusors are available, although they either use or produce tritium, or other long lived decay products. As an alternative to the large facilities and the radio-toxicology of current portable sources research is being performed with an aim to produce a fusion based neutron source with neither of these concerns. We show that MCNPX is able to accurately reproduce (p,n) reactions for a number of light elements. Simulations of low energy proton reactions with light nuclei simulated with MCNPX and Geant4 are compared with experiment.  
 
MOPFI073 Optimisation Studies of a High Intensity Electron Antineutrino Source target, proton, simulation, cyclotron 449
 
  • A. Bungau, R.J. Barlow
    University of Huddersfield, Huddersfield, United Kingdom
  • J.R. Alonso, J.M. Conrad, J. Spitz
    MIT, Cambridge, Massachusetts, USA
  • M. Shaevitz
    Columbia University, New York, USA
  
  ISODAR (Isotopes-Decay-At-Rest) is a novel, high intensity source of electron antineutrinos produced by the decay of Li-8 isotopes, which aims for searches for physics beyond the standard model. The Li-8 isotopes are produced in the inelastic interactions of low energy protons or deuterons with a Beryllium target. In addition the Li-8 is produced in the surrounding materials by secondary neutrons. This paper focuses on the optimisation of the base design target, moderator and reflector.  
 
MOPME057 Preliminary Operation of the Beam Loss Monitoring System at the 100-MeV Proton Linac monitoring, linac, high-voltage 601
 
  • S.P. Yun, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song
    KAERI, Daejon, Republic of Korea
  
  A 100-MeV proton linac has been developed as the 1st phase of KOMAC (Korea Multi-purpose Accelerator Complex) under the project name of PEFP (Proton Engineering Frontier Project). The accelerator operation has to be carried out with the objective of limiting beam losses to less than 1 W/m. When the un-intended excessive beam loss occur, the BLM(Beam Loss Monitor) inform this beam loss to operator and transmit the signal to the MPS (Machine Protection System) for the rapid shut-off of the machine. The scintillation detector and proportional counter were selected as the BLM detector because of their fast response time and high sensitivity. At the beam commissioning stage, 20 BLMs will be prepared for the beam loss monitoring. This paper will report preliminary operation results of beam loss monitoring system.
This work was supported by the Ministry of Education, Science and Technology of the Korean Government. 		 
 
MOPWA007 Operating Experience of Kicker Magnet System in the J-PARC 3GeV RCS kicker, high-voltage, synchrotron, extraction 678
 
  • K. Suganuma, M. Kinsho, T. Togashi, M. Watanabe
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been provided proton beam to the Material and Life Science Facility (MLF)as well as to the 50 GeV Main Ring (MR). Proton beam is accelerated from 181 MeV to 3GeV in the RCS and immediately extracted it to the beam transport line to the MLF and the MR. Extraction kicker system is used for this fast extraction. The RCS has been operated for the neutron and MLF users program from December 23rd, 2008. At the beginning of user operation there were many troubles for the extraction kicker system, especially, thyratron which are used for switch of power supply often caused failure. The beam stop rate due to RCS extraction kicker system was more than 13% in the total beam stop of the J-PARC, establishment and operation experience of the tuning for power supply of the extraction kicker make the beam stop rate less than 0.5% in November 2012. In this paper, we are going to report about daily operation whose main is about operation of thyratron and the maintenance held in summer 2012. And　 We also going to report about the aptitude test of thyratron as a plan of the future.  
 
MOPWA067 Robust High-average-power Modulator controls, klystron, power-supply, pick-up 834
 
  • I. Roth, N. Butler, M.P.J. Gaudreau, M.K. Kempkes
    Diversified Technologies, Inc., Bedford, Massachusetts, USA
  
  Funding: US DOE. Grant No. DE-SC0004254
Diversified Technologies Inc. (DTI) designed a modulator which meets the requirements of the Spallation Neutron Source (SNS) modulators at Oak Ridge National Laboratory and will be less expensive than copies of the current modulators. The SNS modulators, under development for a decade, still do not meet the specifications for voltage, droop, or pulsewidth. The modulators must provide pulses of 85 kV, 165 A, with pulsewidths of 1.5 ms and voltage flatness of 1%. The current modulator switches the full power at high frequency during each pulse, and has a complex output transformer. DTI designed a modulator that meets all specifications and is less expensive. The proposed design is cheaper because there is an HV switch that operates at full current only once per pulse, a corrector that switches only 5% of the power at high frequency, a low-cost transformer-rectifier power supply, and no output transformer. DTI’s patented switch uses IGBTs, allowing the switch to operate at full capacity even if 20% of the devices fail. The modulator will be installed in 2013 at SNS to test klystrons. DTI will present the system components of the design as well as the performance results to date. 		 
 
MOPWA074 High Voltage Converter Modulator Optimization high-voltage, controls, feedback, background 852
 
  • A. Scheinker
    LANL, Los Alamos, New Mexico, USA
  • M.J. Bland
    University of Nottingham, Nottingham, United Kingdom
  
  High voltage converter modulators (HVCM) are at the forefront of long pulse high voltage (100kV) technology for Klystron voltage sources. We present results of digitally implementing an extremum seeking (ES) algorithm with which we optimized the rise time of the output voltage of a HVCM at the Los Alamos Neutron Science Center (LANSCE) HVCM test stand by iteratively, simultaneously tuning the first 8 switching edges of each of the three phase drive waveforms (24 variables total). We achieved a 50us rise time, which is reduction in half compared to the 100us currently achieved at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The ES algorithm is successful despite the noisy measurements and cost calculations, confirming the theoretical predictions that the algorithm is not affected by noise unless it both matches exactly the frequency components of the controller's specific perturbing frequencies and is of comparable size.  
 
MOPWA088 FPGA Development Approach for Accelerator Systems with High Integration Complexity controls, alignment 876
 
  • J. Dedič, K. Žagar
    COBIK, Solkan, Slovenia
  • A.M.M. Aulin Söderqvist, N.H. Claesson, R. Tavčar
    Cosylab, Ljubljana, Slovenia
  • J. Neves Rodrigues
    Lund University, Lund, Sweden
  
  During the application-layer FPGA development for timing system for a medical accelerator (accelerator: MedAustron, timing system: Micro Research Finland) and a couple of other FPGA projects (power supply waveform generator, Machine Protection System proof of concept, ESS timing system demo) we got very good insight on how to approach demanding FPGA development that requires team work of many developers, coupled with particularities of accelerator system development. Because subsystems’ specific requirements evolve together with the operational understanding of the entire machine, the careful balance has to be taken between requirements gathering, prototyping and development stage. Furthermore, when doing architectural design decisions, knowledge from multiple domains should be taken into account; accelerator operation, software development and FPGA development. The design shouldn’t be register or counter centric, and FPGA functionality shouldn’t appear to the software developer as fixed – otherwise the design decisions of one world will sooner or later lead to spaghetti-code workarounds in the other world.  
 
MOPWO086 Open XAL Status Report 2013 status, EPICS, controls, target 1076
 
  • T.A. Pelaia
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725
XAL is the well established, accelerator physics high level application programming framework developed for and used at the Spallation Neutron Source in Oak Ridge National Lab. Due to interest from other accelerator labs, the Open XAL project was formed in 2010 to port XAL to be more suitable for collaboration. The Open XAL architecture along with the objectives, status and roadmap of this effort are presented in this paper. 		 
 
MOPWO087 Parameter Estimation of the Exponentially Damped Sinusoid for Noisy Signals closed-orbit, damping, feedback, synchrotron 1079
 
  • T.A. Pelaia
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725
The damped sinusoid equation is a common model for many scientific processes involving damped periodic signals. Here we present two methods for estimating the damped sinusoid parameters for noisy signals. Both methods are based upon an exact, closed form solution to fit the parameters for signals without noise, and they estimate the parameters for the noisy signals by the statistical maximum likelihood criterion. The first method relies on an optimizer to minimize the mean square signal error. The second method estimates the parameters by direct calculation and is suitable when the signal noise is small and the frequencies are sufficiently far from the integer and half integer values. 		 
 
TUOAB101 Installation and Commissioning of the 1.1 MW Deuteron Prototype Linac for IFMIF rfq, linac, proton, ion 1090
 
  • J. Knaster
    IFMIF/EVEDA, Rokkasho, Japan
  • P. Cara, A. Mosnier
    Fusion for Energy, Garching, Germany
  • S. Chel
    CEA/DSM/IRFU, France
  • J. Molla
    CIEMAT, Madrid, Spain
  • H. Suzuki
    Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan
  
  IFMIF, the International Fusion Materials Irradiation Facility, will learn the degradation of the mechanical properties of purpose designed reduced activation ferritic-martensitic steels under bombardment of 14 MeV neutrons at 1018 n/m2s flux reaching values of 150 displacements per atom in the steel lattice. The understanding of the impact of Deuterium-Tritium fusion neutrons in next decade is essential to design and construct a fusion power plant; the next step after ITER. The 14 MeV neutrons are stripped from a liquid Li screen flowing at 15 m/s impacted by 2 parallel 125 mA deuteron beam at 40 MeV. IFMIF project, in its engineering validation phase, will operate in Rokkasho a 125 mA deuteron LINAC at 9 MeV that will validate the concept of IFMIF accelerator, LIPAc. The ion source will inject 140 mA deuterons at 100 KeV in a normal-conducting RFQ that will deliver the bunched beam at 5MeV to be accelerated up to 9 MeV thanks to 8 half-wave superconducting resonators. The installation and commissioning of LIPAc in Rokkasho (Japan) is sequential and the first stage is starting now; the strategy to overcome potential difficulties is detailed.  
slides icon Slides TUOAB101 [2.396 MB]  
 
TUPEA012 Rebunching Ultracold Neutrons by Magnetic Deceleration for the neutron EDM experiment at J-PARC resonance, coupling, power-supply, focusing 1187
 
  • S. Imajo
    Kyoto University, Kyoto, Japan
  • Y. Arimoto
    KEK, Ibaraki, Japan
  • P.W. Geltenbort
    ILL, Grenoble, France
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • M. Kitaguchi
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • Y. Seki
    RIKEN Nishina Center, Wako, Japan
  • H.M. Shimizu
    Nagoya University, Nagoya, Japan
  • T. Yoshioka
    Kyushu University, Fukuoka, Japan
  
  Ultra cold neutrons (UCN) - neutrons with energies less than 300 neV - can be accelerated or decelerated by means of static magnetic and RF fields. Neutron have a magnetic dipole moment, and hence their kinetic energies vary depending on their spin in magnetic fields. Their kinetic energies are restored when they get out from the magnetic field area if their spin did not flip. A spin flip can be triggered by applying an RF field whose frequency coincides with the spin precession frequency of a neutron in this magnetic field. This allows to tune the kinetic energy of neutrons. This method can be used to rebunch a pulsed beam of neutrons to a storage bottle that can store UCN. By open and close the storage bottle synchronously with the rebuncher, high UCN densities can be achieved for precision measurements of neutron properties such as the Electric Dipole Moment. The method and experimental setup are described in detail and the results of a recent first test experiments are presented.  
 
TUPEA043 Linac Design for Nuclear Data Measurement Facility linac, electron, cavity, target 1229
 
  • M. Zhang, W. Fang, Q. Gu, X. Li
    SINAP, Shanghai, People's Republic of China
  
  Pulsed neutrons based on an electron linear accelerator (linac) are effective for measuring energy dependent cross-sections with high resolution by using the time-of-flight (TOF) technique. In this paper, we describe the 15-MeV linac design for the Nuclear Data project in Shanghai Institute of Applied Physics (SINAP). The linac has three operating modes and the maximum average power is 7.5kW. We describe the characteristics of the linac and the study of the beam dynamics is also presented.  
 
WEIB201 Industrial Accelerators electron, ion, radiation, linac 2100
 
  • R.W. Hamm, M.E. Hamm
    R&M Technical Enterprises, Pleasanton, California, USA
  
  Particle accelerators, originally developed for basic science research, are increasingly being employed for industrial applications, with the production of these systems itself a worldwide business conducted by more than 70 companies and institutes. Collectively these entities ship more than 1000 systems per year. The industrial applications of these accelerators cover a broad range of business segments from low energy electron beam systems for welding, machining, and product irradiation to high energy cyclotrons and synchrotrons for radioisotope production and synchrotron radiation production. This talk is a review of these business segments and their impact on our lives and the economy. It will also cover new accelerator technology under development that will be used by industry in the future and the predicted growth in the various business segments.  
slides icon Slides WEIB201 [3.937 MB]  
 
THOAB101 Laser Wire Based Parallel Profile Scan of H− Beam at the Superconducting Linac of Spallation Neutron Source laser, ion, linac, pick-up 3090
 
  • Y. Liu, A.V. Aleksandrov, D.L. Brown, R. Dickson, C. Huang, C.D. Long
    ORNL, Oak Ridge, Tennessee, USA
  • C.C. Peters
    ORNL RAD, Oak Ridge, Tennessee, USA
  
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
We report on the world’s first experiment of a parallel profile scan of the hydrogen ion (H−) beam using a laser wire system. The system was developed at the superconducting linac (SCL) of the Spallation Neutron Source (SNS) accelerator complex. The laser wire profile scanner is based on a photo-detachment process and therefore can be conducted on an operational H− beam in a nonintrusive manner. The parallel profile scanning system makes it possible to simultaneously measure profiles of the 1-MW neutron production H− beam at 9 different locations (corresponding to energy levels of 400 – 950 MeV) of the superconducting linac using a single light source. The entire measurement process takes less than 5 minutes to complete. Together with the hardware modification, we have also upgraded our user interface to visualize the 9-pairs of H− beam profiles in a real-time fashion, which presents a highly intuitive and informative picture of the H− beam propagation along the acceleration path. The laser wire based parallel profile scanning system provides a powerful tool for accelerator operators and physicists to study the SCL modelling, monitor and/or tune the beam parameters. 		 
slides icon Slides THOAB101 [2.277 MB]  
 
THOAB202 Secondary Neutron Production from Patients during Hadron Therapy and their Radiation Risks: the Other Side of Hadron Therapy ion, target, proton, hadron 3118
 
  • M.A. Chaudhri
    University of Erlangen-Nuernberg, Erlangen, Germany
  
  We were the first to calculate and measure the neutron produced from patients during therapy with bremsstrahlung, and estimated their radiation doses *. This neutron output would be lot higher with hadrons due to their larger cross sections. There is no reliable/ useful data on this subject. Using the experimental neutron production data from different body elements, we have estimated the fluence and energies of these neutrons from tissue under irradiation with different hadrons. Our results indicate that at least 4.2 neutrons , with energies greater than 5 MeV, are produced for every C-ion of 400 MeV/u energy incident on tissue. This number reduces to 3, 1.4 and 0.3 respectively at C-energies of 300, 200 and 100 MeV /u. For protons these numbers are estimated to be 0.05, 0.2 and 0.4 per proton of energies 100, 200 and 300 MeV respectively. There would be even more neutrons with energies lesser than 5 MeV. The doses to some organs have been estimated, which are not negligible. A “Compromise optimum energy” concept is suggested. But extreme caution is highly recommend before treating patients with hadrons, especially children and younger people who still have many years to live.
* P.Allen and M.A Chaudhri, Phys. Med. Biol. 33 (1988) 1017
 		 
slides icon Slides THOAB202 [3.644 MB]  
 
THOAB203 100 MeV/100kW Electron Linear Accelerator Driver of the NSC KIPT Neutron Source electron, target, gun, bunching 3121
 
  • A.Y. Zelinsky, N. Ayzatsky, O. Bezditko, I.M. Karnaukhov, V.A. Kushnir, V. Mitrochenco
    NSC/KIPT, Kharkov, Ukraine
  • Y.L. Chi, X.W. Dai, C.D. Deng, M. Hou, X.C. Kong, R.L. Liu, W.B. Liu, C. Ma, G. Pei, S. Pei, H. Song, S. Wang, J.B. Zhao, Z.S. Zhou
    IHEP, Beijing, People's Republic of China
  • Y. Gohar
    ANL, Argonne, USA
  
  In NSC KIPT, Kharkov, Ukraine a neutron source based on a subcritical assembly driven by a 100MeV/100kW electron linear accelerator will be constructed. This neutron source is an USA (ANL)-Ukraine (KIPT) Joint project, and its Accelerator will be designed and constructed by Institute of High Energy Physics (IHEP), China. The design and construction of such a Accelerator with high average beam current and low beam power losses is a technical challenging task. In the paper, the main accelerator features and current status are under discussion.  
slides icon Slides THOAB203 [8.585 MB]  
 
THPEA038 ESS Naming Convention target, controls, linac, vacuum 3222
 
  • K. Rathsman, G. Trahern
    ESS, Lund, Sweden
  • J. Malovrh Rebec, M. Reščič, M. Vitorovic
    Cosylab, Ljubljana, Slovenia
  
  The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon thermal neutrons. The main facility will be built in Lund, Sweden. Construction is expected to start 2013 and the first neutrons will be produced in 2019. The ESS linac will deliver 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The ESS Naming Convention is based on a standard, originally developed for the Super Superconducting Collider (SSC) and later adopted by other large research facilities, e.g. the Spallation Neutron Source (SNS), Facility for Rare Isotope Beams (FRIB), International Thermonuclear Experimental Reactor (ITER), and the Continuous Electron Beam Accelerator Facility (CEBAF). The ESS Naming Convention was agreed upon and approved at a very early stage of the ESS project in order to establish a standard before names started to evolve. The main scope was to standardise meaningful, yet short and mnemonic signal and device names. The present paper describes the naming convention, the site wide implementation at ESS and associated web based tools.  
 
THPEA039 Radiation Protection Study for the Shielding Design of the LINAC 4 Beam Dump at CERN linac, shielding, radiation, simulation 3225
 
  • J. Blaha, J. Vollaire
    CERN, Geneva, Switzerland
  
  Linac4, a new 160 MeV H− accelerator, is currently being constructed at CERN. The accelerator is terminated by a dump collecting beam which is not intended for further utilization. The aim of this study is to determine an optimal shielding of the beam dump fulfilling the radio-protection requirements. The proposed shielding must take into account different accelerator operational phases, the space constraints inside the accelerator vault as well as the decommissioning of the installation at the end of its lifetime. Therefore a detailed Monte-Carlo calculation using FLUKA particle transport and interaction code has been performed and the relevant physics quantities have been evaluated for different irradiation profiles and shielding material. Moreover, the residual dose rate and induced activation have been calculated for several cooling times in order to optimize the choice of the shielding material following the ALARA principle. Finally the airborne radioactivity induced by particles escaping the shielding as well as the activation of the beam dump cooling water have been also calculated using FLUKA and simplified laminar flow models.  
 
THPFI026 DESIGN OF CSNS R DUMP WINDOW vacuum, target, extraction, proton 3354
 
  • L. Liu, L. Kang, X.J. Nie, H. Qu
    IHEP, Beijing, People's Republic of China
  
  The China Spallation Neutron Source (CSNS) accelerator systems will provide a 1.6 Gev proton beam to a target for neutron production. The extraction dump is used to incept the waste beam in the Ring-Target transport line. At the end of the beam pipe, we adopt a thin window to ensure the accelerator vacuum. When beam gets across the window, temperature of the window will be elevator because of the energy deposit. So, the study on structure and thermal stress analysis is necessary. This article expatiates the way on calculating the energy deposit and thermal stress analyses.  
 
THPFI027 STUDY ON STRUCTURE AND THERMAL ANALYSIS OF CSNS R BEAM DUMP shielding, controls, proton, target 3356
 
  • L. Liu, L. Kang, X.J. Nie, H. Qu
    IHEP, Beijing, People's Republic of China
  
  The China Spallation Neutron Source (CSNS) accelerator systems will provide a 1.6 Gev proton beam to a target for neutron production. Beam dump system is an important part of CSNS, and it is used to incept the waste beam. The beam dump system is composed with vacuum part and shielding part. For the design of shielding part, the material is steel at the centre and concrete outside, we must control the temperature of steel and concrete not too high, and it will be a serious problem that the concrete crazes because of the high temperature. So the thermal analyses must be done to ensure safety. Taking CSNS R dump for example, we use software to make model and analyze the thermal, then optimizing the result. According to the result, we control the work time and dimension of the beam to control the temperature of the iron and concrete. This article expatiate the study on the structure design and thermal analyses.  
 
THPFI028 Anti-earthquake Structural Design for CSNS Beam Dump acceleration, vacuum 3358
 
  • X.J. Nie, L. Kang, L. Liu, H. Qu
    IHEP, Beijing, People's Republic of China
  
  To ensure the beam dump shield iron can resist the damage of earthquake and maintain the normal protective capability, anti-earthquake design was carried out in this paper. The parts for seismic resistance were designed according to the feature of foundation building. The force model was reached through the analysis of seismic load. The structure dimension was decided on the basis of the theory of strength. A pre-buried plate with hooks was achieved and the force model was simplified as fixed end. The minimal diameter of hook showed 30mm. The fixing device with plate decreases the precision requirement of foundation building and can be used to fix the shield iron to resist the earthquake.  
 
THPFI029 The Structure Design and Analysis of Proton Beam Window for CSNS radiation, target, proton, scattering 3361
 
  • H.J. Wang, L. Kang, R.H. Liu, H. Qu, D.H. Zhu
    IHEP, Beijing, People's Republic of China
  
  The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). In this paper, a new designed PBW structure called single-double layer structure is discussed. The new structure will be used in CSNS, and it is designed based on the beam characteristic of CSNS, which power is 100 kW. The structure design and thermal-analysis are presented, and the convective coefficient of cooling water is calculated. Besides, the radiation damage is discussed to assure there is no danger of radiation lifetime of PBW.  
 
THPFI032 The Design and Analysis of Proton Beam Window for CSNSIII scattering, proton, radiation, target 3367
 
  • H.J. Wang, L. Kang, R.H. Liu, H. Qu, D.H. Zhu
    IHEP, Beijing, People's Republic of China
  
  The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). When the beam power of CSNS upgrades from 100kw to 500kw (CSNSIII), the present single-double layer structure of PBW cannot meet the demands. The PBW will be changed to other structure. This paper discusses sandwiched structure and multiple pipe structure, and the later one is chosen as the PBW of CSNSIII. An appropriate convective coefficient of cooling water is chosen, based on which the detailed thermal-stress analysis is presented. Besides, the lifetime is estimated. All these analyses show the designed PBW can work well in CSNSIII.  
 
THPFI065 Thermo-mechanical Investigations of the SINQ "Cannelloni" Target target, simulation, factory, scattering 3445
 
  • R. Sobbia, S. Dementjevs, S. Joray, M. Wohlmuther
    PSI, Villigen PSI, Switzerland
  
  Numerical results of three-dimensional ANSYS thermo-mechanical simulations of single components of the SINQ target system are presented. Thermal stresses are generated by energy deposition in so-called ‘‘cannelloni'' consisting of a Zircaloy-2 rod filled with Lead to 90% of its inner volume. The molten region of the inner Lead filling is calculated by thermal analysis using the energy deposition profile imported from MCNPX calculations. Induced mechanical stresses are studied for a set of predefined parameters, the heat transfer coefficient and the bulk temperature of the heavy water cooling system. Critical stress regions are investigated to provide possible failure scenarios and overall system performance.  
 
THPFI080 NSC KIPT Neutron Source on the Base of Subcritical Assembly Driven with Electron Linear Accelerator target, electron, klystron, radiation 3481
 
  • A.Y. Zelinsky, O. Bezditko, P.O. Demchenko, I.M. Karnaukhov, V. Oleinik, F.A. Peev, I. Ushakov, O.M. Vodin
    NSC/KIPT, Kharkov, Ukraine
  • Y. Gohar
    ANL, Argonne, USA
  
  National Science Center “Kharkov Institute of Physics and Technology” (NSC KIPT, Kharkov, Ukraine) together with Argonne National Laboratory (ANL, USA) develops the conceptual project of a neutron source based on the sub-critical assembly driven by electron linear accelerator. The main functions of the subcritical assembly are support of the nuclear industry and medical researches. Reactor physics and material researchs will be carried out at the facility. For subcritical assembly design proven techniques and practices are used to enhance its utilization. The goal of the development is to create in Ukraine the experimental basis for neutron research based on safe intensive sources of neutrons. The main facility components are an electron linear accelerator, a system for electron beam transportation from linear accelerator to the target, neutron production target, subcritical assembly, biological shield, neutron channels and auxiliary supporting systems.  
 
THPME007 HTS Magnet to Polarize Ultra Cold Neutrons dipole, simulation 3522
 
  • K. Hatanaka, M. Fukuda, N. Hamatani, K. Kamakura, T. Saito, H. Ueda, Y. Yasuda, T. Yorita
    RCNP, Osaka, Japan
  • T. Kawaguchi
    KT Science Ltd., Akashi, Japan
  
  We have developed magnets using High Temperature Superconductor (HTS) wires for this decade. A HTS magnet was designed and fabricated to polarize ultra cold neutrons (UCN). It consists of 10 double pancakes and the number of the total winding is 2,800 turns. The inner diameter of the coil is 131.5 mm and the coil is 105 mm long. The coil is conduction cooled by a pulse tube cryocooler and the operating temperature is expected to be 20 K. The maximum rated current is 200 A and the magnetic field is higher than 3.5 T at the center. Results of cooling tests and field measurements are presented.  
 
THPWA002 Optimization of the Photoneutron Flux Emitted by an Electron Accelerator for Neutron Interrogation Applications using MCNPX and TRIPOLI-4 Monte Carlo Codes target, electron, photon, simulation 3630
 
  • A. Sari, F. Carrel
    CEA/DRT/LIST, Gif-sur-Yvette Cedex, France
  • C. Jouanne, A. Lyoussi, O. Petit
    CEA, Gif-sur-Yvette, France
  
  Various applications require neutron interrogation to detect special nuclear material. In a previous study*, we demonstrated the feasibility of this technique using the photoneutron flux emitted by a 16 MeV linear electron accelerator. This approach enables to reach average emission intensity on the order of one decade beyond the one produced by deuterium-tritium neutron generators traditionally used for such applications. Higher average emission intensities of the photoneutron flux would enable to expand boundaries of neutron interrogation. This new study aims at optimizing the photoneutron flux emitted by an electron accelerator. In order to ensure accuracy and reliability of our results, two Monte Carlo particle transport codes were used in parallel in this study: MCNPX developed by Los Alamos National Laboratory, and TRIPOLI-4 developed by the French Alternative Energies and Atomic Energy Commission. Potential discrepancies between results obtained with the two codes were investigated. Furthermore, careful attention was given to minimize the high-energy photon beam contained in the photoneutron flux in order to reduce spurious photofission reactions during measurements.
*A. Sari et al., IEEE Trans. Nucl. Sci., vol. 59, no.3, pp. 605-611, 2012. 		 
 
THPWA009 Generation of Laser Compton Scattered Gamma-rays from a 150-MeV Microtron laser, microtron, scattering, photon 3645
 
  • R. Hajima, C.T. Angell, I. Daito, T. Hayakawa, M. Kando, T. Shizuma
    JAEA, Ibaraki-ken, Japan
  • H. Ohgaki
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  
  Funding: This work was supported in part by special coordination funds for promoting science and technology in Japan (Grant No. 066).
We have developed a laser Compton scattered gamma-ray source based on a 150-MeV racetrack microtron at Japan Atomic Energy Agency. The microtron equipped with a photocathode RF gun accelerates a single bunch of electrons to collide with a laser pulse from a Nd:YAG laser. We have employed laser pulse compression by stimulated Brillouin scattering to obtain high-flux gamma-rays, > 105 ph/s. The gamma-ray source is a prototype of commercial machine for nuclear security applications, non-destructive detection of nuclear material hidden in a ship cargo. Design and performance of the gamma-ray source are presented. 		 
 
THPWA010 Application of X-band 30 MeV Linac Neutron Source to Nuclear Material Analysis for Fukushima Nuclear Plant Accident linac, electron, target, scattering 3648
 
  • M. Uesaka, K. Dobashi, T. Fujiwara
    The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
  • H. Harada
    JAEA, Ibaraki-ken, Japan
  • K. Tagi
    University of Tokyo, Tokyo, Japan
  • M. Yamamoto
    Accuthera Inc., Kawasaki, Kanagawa, Japan
  
  We plan to use our X-band (11.424GHz) electron linac as a neutron source for the nuclear analysis for the Fukushima nuclear plant accident. Quantitative material analysis and forensics for nuclear security will start several years later after the safe settlement of the accident is established. For the purpose, we should now accumulate more precise nuclear data of U, Pu, TRU and MA especially in epithermal (0.1-10 eV) neutrons. Therefore, we have decided to move the linac into the core of the experimental nuclear reactor “Yayoi” which is now under the decommission procedure. First we plan to perform the TOF (Time Of Flight) transmission measurement of the total cross sections of the nuclei for 0.1-10 eV neutrons. Electron energy, macro-pulse length, power and neutron yield are ~30 MeV, 100 ns – 1 micros, <0.5 kW and <1012 n/s, respectively. Optimization of the design of a neutron target (Ta, W, U), TOF line and neutron detector (Ce:LiCAF) of high sensitivity and fast response is underway. Installation, commissioning and measurement starts in 2014. Detailed design and way how to contribute to the analysis of the Fukushima nuclear plant accident will be presented.  
 
THPWA019 THEORY RESEARCH ON APPLICATION OF CT TECHNOLOGY TO SHIELDED NUCLEAR MATERIAL DISCRIMINATION electron, radiation, resonance, factory 3669
 
  • Y. Zhang, H.B. Chen, Q. Gao, J. Shi
    TUB, Beijing, People's Republic of China
  
  Smuggling of nuclear material is a serious threat to security of international society. Formal research on nuclear material discrimination can fulfil customs inspection requirement. This paper designs a situation that nuclear material which is packaged and shielded by heavy metal need to be discriminated accurately on the condition that the object being detected cannot be dismantled. Calculation results prove nuclear material could be discriminated accurately while the ideal condition is fulfilled. If multi-energy X-ray source is used the discrimination accuracy is declined. However the accuracy could be improved while energy spectrum shaping technique is used.  
 
THPWA031 Raising the Generating Current in the VITA Neutron Source for BNCT proton, ion, target, vacuum 3693
 
  • A.S. Kuznetsov, V.I. Aleynik, A.G. Bashkirtsev, D.A. Kasatov, A.N. Makarov, I.M. Schudlo, I.N. Sorokin, S.Yu. Taskaev, M.A. Tiunov
    BINP SB RAS, Novosibirsk, Russia
  
  Funding: The work was partially supported by the Ministry of Education and Science of the Russian Federation (contract № 14.518.11.7039).
The Vacuum Insulated Tandem Accelerator (VITA) was developed in the Budker Institute of Nuclear Physics to produce epithermal neutrons for boron neutron capture therapy in the 7Li(p,n)7Be reaction. The parameters of the generated radiation allow us to carry out in vitro and in vivo investigations of BNCT. In present moment the modernization of the facility elements is carrying out to meet the parameters required for clinical usage. As the first step of the modernization the stripping target and electrode apertures were optimized. The experiments on fine beam injection were carried out as well as experiments on high current transportation. The output current in the range 1.5-2.5 mA with proton beam energy of 1 – 2 MeV was obtaned in the routine regimes of generation. In presented work the results of the experiments and possible way to rise the proton current higher then 3 mA level with energy 2 MeV are discussed.
*S. Taskaev, et al. Vacuum-insulation Tandem Accelerator for Boron Neutron Capture Therapy. Proc. 2nd International Particle Accelerator Conference (IPAC-2011),2011, San Sebastian, Spain, p.3615-3617. 		 
 
THPWA037 PIP: A Low Energy Recycling Non-scaling FFAG for Security and Medicine target, proton, cyclotron, isotope-production 3711
 
  • R.J. Barlow, T.R. Edgecock
    University of Huddersfield, Huddersfield, United Kingdom
  • C. Johnstone
    Fermilab, Batavia, USA
  • H.L. Owen
    UMAN, Manchester, United Kingdom
  • S.L. Sheehy
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  
  PIP, the Producer of Interacting Protons, is a low energy (6-10 MeV) proton nsFFAG design that uses a simple 4-cell lattice. Low energy reactions involving the creation of specific nuclear states can be used for neutron production and for the manufacture of various medical isotopes. Unfortunately a beam rapidly loses energy in a target and falls below the resonant energy. A recycling ring with a thin internal target enables the particles that did not interact to be re-accelerated and used for subsequent cycles. The increase in emittance due to scattering in the target is partially countered by the re-acceleration, and accommodated by the large acceptance of the nsFFAG. The ring is essentially isochronous, the fields provide strong focussing so that losses are small, the components are simple, and it could be built at low cost with existing technology.  
 
THPWA038 GEANT4 Studies of Magnets Activation in the HEBT Line for the European Spallation Source proton, target, quadrupole, octupole 3714
 
  • C. Bungau, R.J. Barlow, A. Bungau, R. Cywinski, T.R. Edgecock
    University of Huddersfield, Huddersfield, United Kingdom
  • P. Carlsson, H. Danared, F. Mezei
    ESS, Lund, Sweden
  • A.I.S. Holm, S.P. Møller, H.D. Thomsen
    ISA, Aarhus, Denmark
  
  The High Energy Beam Transport (HEBT) line for the European Spallation Source is designed to transport the beam from the underground linac to the target at the surface level while keeping the beam losses small and providing the requested beam footprint and profile on the target. This paper presents activation studies of the magnets in the HEBT line due to backscattered neutrons from the target and beam interactions inside the collimators producing unstable isotopes.  
 
THPWA039 GEANT4 Target Simulations for Low Energy Medical Applications target, simulation, proton, cyclotron 3717
 
  • N. Ratcliffe, R.J. Barlow, A. Bungau, C. Bungau, R. Cywinski
    University of Huddersfield, Huddersfield, United Kingdom
  
  The GEANT4 code offers an extensive set of hadronic models for various projectiles and energy ranges. These models include theoretical, parameterized and, for low energy neutrons, data driven models. Theoretical or semi-empirical models sometimes cannot reproduce experimental data at low energies(<100MeV), especially for low Z elements, and therefore recent GEANT4 developments included a new particle\hp package which uses evaluated nuclear databases for proton interactions below 200 MeV. These recent developments have been used to study target designs for low energy proton accelerators, as replacements of research reactors, for medical applications. Presented in this paper are results of benchmarking of these new models for a range of targets, from lithium neutron production targets to molybdenum isotope production targets, with experimental data. Also included is a discussion of the most promising target designs that have currently been studied.  
 
THPWA047 GEM*STAR - New Nuclear Technology to Produce Inexpensive Diesel Fuel from Natural Gas and Carbon controls, linac, proton, target 3738
 
  • R.P. Johnson, F. Marhauser
    Muons. Inc., USA
  • C. Bowman, R.B. Vogelaar
    ADNA, Los Alamos, New Mexico, USA
  
  The 75,000 tons of US stored spent nuclear fuel (SNF) from conventional nuclear reactors is a resource that could provide 125 years of all US electrical power. Or it could also provide a great amount of process heat for many applications like producing green diesel fuel from natural gas and renewable carbon. An accelerator system like the SNS at ORNL can provide neutrons to convert SNF into fissile isotopes to provide high temperature heat using technology developed at the ORNL Molten Salt Reactor Experiment. In the GEM*STAR accelerator-driven subcritical reactor that we wish to build, the accelerator allows subcritical operation (no Chernobyls), the molten salt fuel allows volatiles to be continuously removed (no Fukushimas), and the SNF does not need to be enriched or reprocessed (to minimize weapons proliferation concerns). The molten salt fuel and the relaxed availability requirements of process heat applications imply that the required accelerator technology is available now. A new opportunity has arisen to use GEM*STAR to reduce the world’s inventory of weapons-grade plutonium leaving only remnants that are permanently unusable for nuclear weapons.
* Charles D. Bowman et al., “GEM*STAR: The Alternative Reactor Technology Comprising Graphite, Molten Salt, and Accelerators,” Handbook of Nuclear Engineering, Springer (2010).
 		 
 
THPWO037 Status and Progress of the J-PARC 3 GeV RCS injection, target, beam-transport, extraction 3848
 
  • M. Kinsho
    JAEA/J-PARC, Tokai-mura, Japan
  
  The J-PARC rapid cycling synchrotron (RCS) has been delivered 300kW beam to both the MLF and the MR with high reliability and small beam loss for user operation. To realize simultaneously two kinds of beam shape which are required from the MLF and the MR, two pulse dipole magnets for injection painting were installed in the beam transport line from the Linac to the RCS. It was successful to make two kinds of beam shape with injection painting bump magnets and these added pulse dipole magnets. This injection painting system is used for user operation and works well for reduction of beam losses. Not only user operation but also high power beam test was performed, and beam power of 524kW for 35 second was achieved with low beam loss in the RCS. Almost all beam loss was localized at the ring collimator and the loss rate was about 2% and this was acceptable because design value of the beam loss was 3%. This power corresponds to 1.8MW for 400MeV injection in terms of the Lasslett tune shift. In this high-intensity trial, significant progress toward design output beam power of 1 MW was demonstrated. The status and progress of the RCS in J-PARC are presented.  
 
THPWO051 Status of CPHS Project proton, linac, target, rfq 3887
 
  • S.X. Zheng, H.B. Chen, C. Cheng, Q. Du, T. Du, X. Guan, X.Y. Jia, C. Jiang, H.T. Lu, C.-X. Tang, D. Wang, D. Wang, X.W. Wang, H.Y. Zhang, Z. Zhang
    TUB, Beijing, People's Republic of China
  • W.Q. Guan, Y. He, J. Li, D.-S. zhang
    NUCTECH, Beijing, People's Republic of China
  
  CPHS (Compact Pulsed Hadron Source) project was initiated in Tsinghua University at 2009. It consists of a 13 MeV proton Linac (RFQ+DTL), a neutron target station and some neutron stations. The construction of 3 MeV Linac (RFQ only) and target station will be finished at the end of 2012. And initial commissioning will be started at the early of year 2013. The progress and results of early commissioning will be presented at this paper. Then we will report the next plan also.  
 
THPWO073 European Spallation Source Afterburner Concept proton, target, kicker, linac 3924
 
  • D.P. McGinnis, M. Lindroos, R. Miyamoto
    ESS, Lund, Sweden
  
  The European Spallation Source (ESS) is a long pulsed source based on a high power superconducting linac. The long pulse concept is an excellent strategy of maximizing high beam power while minimizing peak power on the target. Chopping in the long pulse concept provides the necessary resolution for many neutron physics applications. However, there are some neutron physics applications in which both peak neutron flux and high resolution are desired. The peak flux of the ESS can be enhanced by placing an accumulator ring at the end of the linac. A bunch by bunch extraction scheme can be used to optimize the proton pulse time profile that maximizes peak neutron flux while minimizing instantaneous beam power on the target.  
 
THPWO083 Simulation of a Beam Rotation System for the SINQ Spallation Source at PSI target, proton, simulation, optics 3954
 
  • D. Reggiani, T. Reiss, M. Seidel, V. Talanov, M. Wohlmuther
    PSI, Villigen PSI, Switzerland
  
  With a nominal beam power of nearly 1 MW on target, the PSI-SINQ ranks among the world's most powerful neutron spallation sources. The proton beam transport to the SINQ target is carried out exclusively by means of linear elements. As a consequence, at the SINQ target entrance the beam presents Gaussian transverse x and y distributions with tails cut short by collimators. This leads to a highly uneven temperature distribution inside the SINQ zircaloy target, giving rise to thermal and mechanical stress. In view of a future beam intensity upgrade, the possibility of homogenizing the beam distribution by means of a fast beam rotation system is currently under study. Important aspects of this method concern the resulting neutron spectrum and flux distribution. The simulations of the beam distribution achievable thanks to this technique as well as its consequences in terms of neutron production are presented in this contribution.  
 
THPWO084 Optimization of a Bi-spectral Boxed Side-by-Side Moderator for the Target-Moderator-Reflector System of the ESS target, scattering, proton, brightness 3957
 
  • T. Reiss, U. Filges, V. Talanov, M. Wohlmuther
    PSI, Villigen PSI, Switzerland
  • F. X. Gallmeier
    ORNL, Oak Ridge, Tennessee, USA
  
  Providing bi-spectral neutron beams is one of the main neutronics design criteria for the target-moderator-reflector (TMR) system of the European Spallation Source, to be built in Lund (Sweden). As a first step, the requirements of neutronics instruments regarding the neutron spectrum are formulated, a figure of merit is defined. In order to maximize the moderator performance to obtain bi-spectral neutron extraction, a parametrized model of the TMR system is developed and used with a MCNPX-based optimization framework. This model is then used to study and optimize the moderator performance, especially in the thermal and cold parts of the spectrum. Results obtained with an optimized moderator setup are dicussed and compared with the requirements of the instruments.  
 
THPWO085 Numerical and Experimental Study for the Characterization of the Spallation Target Performance of the Ultracold Neutron Source at the Paul Scherrer Institut target, shielding, simulation, proton 3960
 
  • V. Talanov, M. Wohlmuther
    PSI, Villigen PSI, Switzerland
  
  Results of numerical calculation and experimental characterization of the neutron flux profile in the vicinity of the ultracold neutron source (UCN) at the Paul Scherrer Institut (PSI) are presented. At first, the MCNPX-based model of the Monte-Carlo simulation with its detailed description of the so-called ‘Cannelloni’-type spallation target assembly and the realistic proton beam profile modeling is described. Thereafter the experimental determination of the thermal neutron flux profile using the gold foil activation, along the height of the UCN vacuum tank, starting from the proton beam plane, is presented. Both calculations and measurements were performed for the standard operation mode, with several seconds of the full proton beam on the target. Finally, a comparison of simulation and experimental results is discussed.