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Development of Pulsed Neutron Sources パルス中性子源の開発

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Development of Pulsed Neutron Sources パルス中性子源の開発 23/12/2020 Development of Pulsed Neutron Sources パルス中性子源の開発 Yoshiaki Kiyanagi 鬼柳善明 Nagoya University 名古屋大学工学研究科 1 History of Pulsed Neutron Sources （Change of plans from 1990） ESS SNS J-PARC (2022?) (2006) (2008) (1982) (1985) IPNS(1981) KENS(1980) 136MeV 1971 1959 300MeV 45MeV Hokkaido 1973 45MeV 2 Accelerator-driven Neutron Sources before KENS established in 1980 (Electron Acc.) （Except for nuclear data measurements） Hokkaido University The Gaerttner Linear Accelerator Center at Rensselaer Polytechnic Institute (RPI) Harwell Linac Linac at Laboratory of Nuclear Science at （opposite present ISIS) Tohoku University (LNS) （Present: Research Center for Electron Photon Science） 3 National Laboratory for High Energy Physics: KEK （Now, High Energy Accelerator Research Organization） Booster Synchrotron Utilization Facility KENS：KEK Neutron Source （KEK中性子源) Green area Proton therapy Muon https://www2.kek.jp/openhouse/1996/image/BSF/BSF7.gif 4 Coupling of Target-Moderator- Reflector research Late Prof. Watanabe performed experiments using a RI neutron source. スパレーション・パルス中性子源KENSとそれによる中性子散乱 渡邊昇、佐々木寛、石川義和 日本原子力学会誌 Vol. 23, No. 6 (1981) 389-398 5 Development of a Methane Cold Moderator at Hokkaido University Cylindrical shape Neutron Energy Spectra Spectra Energy Neutron moderator with a re-entrant hole Neutron Energy (eV) K. Inoue, N. Otomo, H. Iwasa and Y. Kiyanagi, J. Nuclear Science and Technology, Vol.11, No.5, pp.228-229, (1974) 6 KENS Neutron source Cold source Co-existence Thermal source The first cold neutron source set at a dedicated neutron scattering experimental facility. （There was an opinion a cold source was not necessary for neutron sources based on accelerators） A wise decision by Professors Watanabe and Ishikawa 渡邊昇, 石川義和: 物理学会誌, 39, 826 (1984). 渡邊昇、佐々木寛、石川義和 7 日本原子力学会誌 Vol. 23, No. 6 (1981) 389-398 Conversion of KENS Al Window Cd Al Energy spectra Deformation of a cold neutron beam hole Fig. 2 Interior of Cadmium Liner of Cold Neutron Source Be-C layered reflector Be cost of 40 million yen was reduced. Pulse shapes From enriched B to nat-B A Gd-poison plate was inserted. Improved TMRA 8 J-PARC/MLF （From KEK side） KENS→GEMINI（KENS-II)計画→N-Arena(JHP)→ N-Arena（JHF) (~500kW) J-PARC/MLF（１MW) Neutron Science Research Center（８MW） （From JAEA side） 9 Development of a coupled moderator Methane cannot be used under high radiation field. A traditional hydrogen moderator gave lower intensity than methane. Experiments at Hokkaido University Normal hydrogen and methane electrons 6 times higher intensity than the traditional one, and twice Y. Kiyanagi, N. Watanabe and H. Iwasa, Nucl. Instrum. higher than a decoupled Methods Phys. Res. A312, pp.561-570, (1992) methane moderator. Improvement of pulse shapes by using para-hydrogen 3 106 Experimental results @1.8meV 1.87meV Linear plot Liquid H 5cm Experiment 2.5 106 2 Experiment at Hokkaido 300 Coupled Para35 2 106 Coupled Para35 Coupled Para99 Coupled Para99 250 Coupled Decoupled Para35 Decoupled Para35 Decoupled Para95 1.5 106 Decoupled Para99 Decoupled Para99 200 6 1 10 sec) m Intensity (Aub.Unit) 150 5 105 FWHM ( FWHM 100 0 200 400 600 800 1000 1200 1400 7 10 Time 50 1.87meV Semi-log plot Liquid H 5cm Decoupled 2 0 Experiment at Hokkaido 0.001 0.01 0.1 6 Coupled Para35 10 Coupled Para99 Energy (eV) Decoupled Para35 Decoupled Para99 The pulse shapes are improved by using para-hydrogen, and increase of pulse 105 peaks are also observed. Intensity (Aub.Unit) M. Ooi, H. Ogawa, T. Kamiyama, Y. Kianagi, Nucl. Instrum. Meth. A659, pp.61-68, (2011) 104 0 200 400 600 800 1000 1200 1400 11 TimeTime (msec) Increase of intensity by using a thick moderator J-PARC coupled moderator para25 para50 para75 0eV~0.025eV 1.5 para95 para98 para100 140 mm diameter x 100 mm height 1 12cm Intensity ratio 12cm n t cm 0.5 Horizontal distribution 2 4 6 8 10 12 14 16 18 (measured at Hokkaido U.) thickness(cm) 12 T. Kai, et al., JNST (2017) https://doi.org/10.1080/00223131.2017.1394235 Proton energy 3 GeV was appropriate? Verification of neutron yield using 12 GeV p At that time the NMTC code result indicated level off trend over around 3 GeV. Mn bath experiment *３GeV was in an allowance level. *Target was mercury （G. Bauer) M. Arai, Y. Kiyanagi, N. Watanabe, R. Takagi, H. Shibazaki, M. Numajiri, S. Itoh, T. Otomo, M. Furusaka, Y. Inamura, Y. Ogawa, Y. Suda and S. Satoh: Neutron Production from Lead Targets for 12-GeV Protons, Journal of Neutron Research, Vol.8, pp.71-83, (1999) Target-Moderator-Reflector System for JSNS Cd poison and decoupler Decoupled poisoned moderator -Very high resolution- Proton beam Decoupled moderator -High resolution- Cd decoupler Coupled moderator -High intensity- Target Be reflector Fe reflector-shield14 15 ESS@LUND J-PARC ESS Pancake Butterfly Water Hydrogen Hydrogen Hydrogen High brilliant High intensity Thermal/Cold https://ess-public-legacy.esss.se/sites/default/files/target_station_jpg_full.jpg 16 Accelerator-driven Neutron Sources Worldwide ISIS (UK） 0.2MW ESS (Sweden） 2022? (4MW) HBS CPHS SNS USA) SONATABELINA (IT) SNS-CANS (China) HUNS(Japan) (1.4MW) PKUNIFTY RANS ● ● (China) ● ● KUANS KURRI-LINAC LENS（USA） JSNS/J-PARC LANL（USA） CSNS (China) (Japan) (1MW) (0.08MW) (0.1MW) CAB （Argentina） 17 Neutron Sources in Japan（except for BNCT) Hokkaid U. Aomori prefecture HUNS(32MeV, 100mA) Aomori Prefecture ~104n/sec/cm2 Quantum Science Cold and thermal neutrons Center(20MeV, 50mA) 6.1x105n/sec/cm2 Thermal neutron RIKEN RANS(7MeV, 100mA) JAEA J-PARC ~fewX104n/sec/cm2 KEK (3GV, 333mA) Thermal neutron RADEN: Cold neutron Kyoto U. ~108n/sec/cm2 KUANS (3.5MeV, 100mA) 1.2x103n/sec/cm2 JRR-3 (Reactor) Thermal neutron JAEA TNRF: ~108n/sec/cm2 Thermal neutron KURNS at Kyoto U, CNRF: ~107n/sec/cm2 SUMITOMO KUR (Reactor): Thermal Cold neutron SHI-ATEX E2: ~3.2x105n/sec/cm2@5MW (18MeV, 20mA) B4: ~5x107n/sec/cm2@5MW AIST AISTANS ~2x105n/sec/cm2 KURNS LINAC: Thermal Thermal neutron KURNS Linac 2.3x104n/sec/cm2@100mA 18 For the Future Reflector for cold and very cold neutron source Nano diamond M. Teshigawara et al., NIM A Vol. 929 (2019) P. 113-120 19 Moderator with a re-entrant hole ＊Intensity increase in a hole ( for mfSANS, for example) ＊Simulation for a mesitylene moderator Distance from bottom (cm) Distance from bottom (cm) Simulations at Hokkaido University Neutron Focusing Mirror using a metal base It can be placed near the moderator A fully-revolved 900mm ellipsoidal neutron focusing mirror for J-PARC BL-06 VIN ROSE A 300mm ellipsoidal neutron focusing mirror for focusing SANS beamline at RANS RIKEN Yamagata group T. Hosobata et al., Vol. 27, No. 19 / 16 September 2019 / Optics Express 26807 21 Total optimization using recent technology Optimization from a neutron source to detection. Target Moderator Detector Compact Reflector High Performance Beam transport Instrument High Performance 22 Summary • History of pulsed neutron sources （Large facility） LNS at Tohoku U. →KENS→JSNS/J-PARC HUNS at Hokkaido U. （ ） Compact facilities KUANS→RANS→AISTANS （JCANS：Japan Collaboration on Accelerator- driven Neutron Sources） • It is expected that new technologies promote optimization of the compact neutron sources and lead to contribution to a next generation large facility. 23.
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