08 Applications of Accelerators, Technology Transfer and Industrial Relations

T26 Neutron Sources

Paper Title Page
MOPEA078 Target Optimisation Studies for the European Spallation Source 256
 
  • A. Bungau, R. Cywinski
    University of Huddersfield, Huddersfield
  • C. Bungau
    Manchester University, Manchester
 
 

The European Spallation Source (ESS) is one of Europe's biggest and most prestigious science projects to design and construct the next generation facility for research with neutrons. ESS will be the world's most powerful spallation source and it will provide a unique tool for research into the atomic structure and dynamics of matter. We investigate the effects of the dimensions of the ESS spallation target on the total neutron yield integrated over the neutron energy and emission angle. We also investigate different material choices for the ESS target.

 
MOPEB062 Design and Testing of Cryogenic Systems Dedicated to Neutron Sources 412
 
  • S. Crispel, M. Bonneton
    Air Liquide, Division Techniques Avancées, Sassenage
  • M.F.D. Simon
    F4E, Barcelona
  • J. Teah
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • R. Thiering
    ANSTO, Menai, New South Wales
 
 

Thanks to its experience in past projects in the field of neutron sources, Air Liquide DTA was involved in recent years in two major projects : a new Cold Neutron Source (OPAL) at ANSTO, Australia and a Spallation Neutron Source at ISIS, United Kingdom. The OPAL CNS is a liquid deuterium moderated source operating with a cold box with a refrigeration capacity of 5 kW at 25K designed and manufactured by Air Liquide DTA. ISIS Target Station 2 is a liquid hydrogen and solid methane moderated source for which Air Liquide DTA provided two Helium cold boxes (about 600W) operating at 20K derived from the standard Helial product, one customised cryogenic hydrogen loop, and very specific remote dismountable cryogenic transfer lines. These two cryogenic systems were fully commissioned on Air Liquide DTA dedicated test area before delivery to the customers. The purpose of this paper is to give a compared overview of the design and testing of the proposed cryogenic systems for these two projects.

 
MOPEB063 Neutron Source at the DAΦNE Beam Test Facility 415
 
  • G. Mazzitelli, R. Bedogni, B. Buonomo, M. De Giorgi, A. Esposito, L. Quintieri
    INFN/LNF, Frascati (Roma)
  • P. Valente
    INFN-Roma, Roma
 
 

A neutron source, based on photo-neutron production, has been designed and is under construction to upgrade the electron/positron/photon DAΦNE Beam Test Facility (BTF). We present the feasibility study, the solution chosen and the optimization done in order to maximize the neutron/photon yield as well as the comparison between different simulation codes (FLUKA/GEANT4/MCNPX). The first experimental test is foreseen in March 2010.

 
MOPEB064 Study of FFAG-ERIT Neutron Source 418
 
  • K. Okabe
    University of Fukui, Faculty of Engineering, Fukui
  • Y. Ishi, Y. Mori, T. Uesugi
    KURRI, Osaka
 
 

As for BNCT (boron neutron capture therapy) medical applications, an accelerator-based intense thermal or epithermal neutron source has been strongly requested recently. A scaling type of FFAG accelerator with ERIT (energy/emittance recovery internal target) scheme has been developed for this purpose. In this scheme, the beam emittance degradation caused by the neutron production target are cured by ionization cooling method. In this presentation, recent beam study of ionization cooling and neutron production will be described.

 
MOPEB065 Liquid Hydrogen Absorber for MICE 421
 
  • S. Ishimoto, S. Suzuki
    KEK, Ibaraki
  • M.A. Green
    LBNL, Berkeley, California
  • Y. Kuno, M.Y. Yoshida
    Osaka University, Osaka
  • W. Lau
    OXFORDphysics, Oxford, Oxon
 
 

Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with ~2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

 
MOPEB066 Beam Commissioning of Spallation Neutron and Muon Source in J-PARC 424
 
  • S.I. Meigo, M. Futakawa, M. Ohi, S. Shinichi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Fujimori
    KEK/JAEA, Ibaraki-Ken
 
 

In J-PARC, Materials and Life Science experimental Facility (MLF) is aimed at promoting experiments using the world highest intensity pulsed neutron and muon beams which are produced at a thick mercury target and a thin carbon graphite target by 3-GeV proton beams, respectively. The first beam was achieved at the target without significant beam loss in May 2008. It is succeeded stable operation with beam power of larger than 300 kW. After beam irradiation, the residual dose of radiation on the beam transport line is remarkably small where the highest dose is 20 microSv/h. In order to confirm stable operation of the facility, especially for the wellness of the target, it is important to obtain the beam profile at the target. We developed new technique by using imaging plate which is attached on the target vessel by remote handling technique via master slave manipulators. It is found that the beam profile shows good agreement with the calculation. It is also found that the beam scattering effect on the muon production target shows good agreement with the simulation calculation.

 
MOPEB067 The Novel Method of Focusing-SANS with Rotating Magnetic Sextupole Lens and Very Cold Neutrons 427
 
  • M. Yamada, M. Ichikawa, Y. Iwashita, T. Kanaya, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • K.H. Andersen, P.W. Geltenbort, B. Guerard, G. Manzin
    ILL, Grenoble
  • M. Bleuel
    RID, Delft
  • J.M. Carpenter, L. Jyotsana
    ANL, Argonne
  • M. Hino, M. Kitaguchi
    KURRI, Osaka
  • K. Hirota
    RIKEN, Wako, Saitama
  • S.J. Kennedy
    ANSTO, Menai
  • K. Mishima, H.M. Shimizu, N.L. Yamada
    KEK, Ibaraki
 
 

We have developed a motorized magnetic lens for focusing of pulsed white neutron beams. The lens is composed of two concentric permanent magnet arrays, in sextupole geometry, with bore of 15 mm and magnet length of 66 mm. The inner magnet array is stationary, while the outer array is rotated (the frequency of the modulation of magnetic field inside the bore ν ≤ 25Hz), providing a sextupole magnetic field gradient range of 1.5x104T/m2 ≤ g' ≤ 5.9x104T/m2. By synchronization of a pulsed neutron beam with the sinusoidal modulation of the magnetic field in the lens, the beam is focused, without significant chromatic aberration, over a wide neutron wavelength band. We have constructed a focusing-SANS (Small Angle Neutron Scattering) test bed on the PF2-VCN (Very Cold Neutron) beam line at the Institut Laue-Langevin in Grenoble. The beam image size matched the source size (≈ 3mm) over of wavelength range of 30Å ≤ λ ≤ 48Å with focal length of ~ 2.3 m. Further, we have demonstrated the performance of this device for high resolution time-of-flight (tof) SANS for a selection of polymeric & biological samples, in a compact geometry of just 5 m.

 
MOPEB068 Nuclear Data Measurements with a Pulsed Neutron Facility based on an Electron Linac 430
 
  • G.N. Kim
    Kyungpook National University, Daegu
  • M.-H. Cho, I.S. Ko, W. Namkung
    POSTECH, Pohang, Kyungbuk
  • H.-S. Kang
    PAL, Pohang, Kyungbuk
  • K.S. Kim, M.W. Lee
    CHEP, Daegu
 
 

We report the activities by using the pulsed neutron facility which consists of an electron linear accelerator, a water-cooled Ta target, and a 12-m time-of-flight path. It can be possible to measure the neutron total cross-sections in the neutron energy range from 0.01 eV to few hundreds eV by using the neutron time-of-flight method. A 6LiZnS(Ag) glass scintillator was used as a neutron detector. The neutron flight path from the water-cooled Ta target to the neutron detector was 12.1 m. The background level was determined by using notch-filters of Co, In, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements of several samples (Dy, Nb) are in general agreement with the evaluated data in ENDF/B-VII. The resonance parameters were extracted from the transmission data from the SAMMY fitting and compared with the previous ones. We also report the isomeric yield ratios for isomeric pairs produced from photonuclear reactions by using the bremsstrahlung photons from the 70-MeV electron linac.