Pulsed ultra-cold neutron production using a Doppler shifter at J-PARC
Pulsed ultra-cold neutron production using a Doppler shifter at J-PARC
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J-PARC 使用多普勒频移器产生脉冲超冷中子
DOI：
10.1093/ptep/ptv177
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
S. Yamashita and R. Katayama
中科院分区：
文献类型：
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作者：
S. Imajo;K. Mishima;M. Kitaguchi;Y. Iwashita;N. L. Yamada;M. Hino;T. Oda;T. Ino;H. M. Shimizu;S. Yamashita and R. Katayama
我们在日本质子加速器研究综合体的材料和生命科学实验设施中建造了多普勒移位器型脉冲超冷中子（UCN）源。由脉冲中子源提供的中子束中的速度为136 m的极冷中子（VCN）在宽带多层膜反射镜上被反射减速，产生脉冲UCN。反射镜被固定到2000 rpm旋转臂的尖端，该旋转臂在与VCN相同的方向上以68 m s的速度移动。脉冲UCN的重复频率为8.33 Hz，产生时脉冲的时间宽度为4.4 ms。为了增加UCN通量，新安装或改进了超镜引导、宽带单色镜、聚焦引导和UCN提取引导。输出中子的1 MW当量计数率为cps，而实际的UCN为80 cps。生产时的空间密度为1.4 UCN cm。这种新的UCN源使我们能够研究和开发必要的仪器，为调查的中子电偶极矩。
We have constructed a Doppler-shifter-type pulsed ultra-cold neutron (UCN) source at the Materials and Life Science Experiment Facility of the Japan Proton Accelerator Research Complex. Very cold neutrons (VCNs) with 136 m svelocity in a neutron beam supplied by a pulsed neutron source are decelerated by reflection on anwide-band multilayer mirror, yielding pulsed UCNs. The mirror is fixed to the tip of a 2000 rpm rotating arm moving with 68 m svelocity in the same direction as the VCNs. The repetition frequency of the pulsed UCNs is 8.33 Hz and the time width of the pulse at production is 4.4 ms. In order to increase the UCN flux, a supermirror guide, wide-band monochromatic mirrors, focus guides, and a UCN extraction guide have been newly installed or improved. The 1 MW-equivalent count rate of the output neutrons with longitudinal wavelengths longer than 58 nm iscps, while that of the true UCNs is 80 cps. The spatial density at production is 1.4 UCN cm. This new UCN source enables us to research and develop apparatuses necessary for the investigation of the neutron electric dipole moment.