The prototype neutron flux monitor consists of a high purity ^(235)U fission chamber detector and a'blank'detector,which is a fissile material free detector with the same dimension as the fission chamber detector to identify noise issues such as noise coming from gamma rays.The main parameters of the fission chamber assembly that have been measured in the laboratory are confirmed to approach the technological level of the International Thermonuclear Experimental Reactor(ITER)in the near future.This prototype neutron flux monitor will be further developed to become a neutron flux monitor suitable for the operation phase of D-D fusion on the ITER.
Yang JinweiSong XianyingZhang WeiLi XuLee WenzhongWang ShiqingXiao GongshanYang BoLu Shuangtong
A special neutron diagnostic system is proposed that facilitates the measurement of neutron fluxes and spectra in the neutronics and tritium production-test blanket module （NTTBM） without interrupting the operation of the International Thermal-nuclear Experimental Reactor （ITER）, for studying the multiplication rate in the neutron multiplier and breeding ratio of tritium in the breeder. This system includes an encapsulated foil activation system, micro-fission chamber detectors （MFC）, and a compact neutron spectrometer using a natural diamond detector （NDD）. A helium coolant loop with a reasonable diameter is designed carefully for every measurement channel that ensures that the neutron detectors and preamplifiers would work well under a high temperature scenario and that the filling rates of the neutron multiplier （beryllium pebble） and tritium breeder material （Li4SiO4） would not decrease excessively （the expected value〉80%） due to the dimensions of the helium coolant loop.
根据第一壁后聚变中子通量和能谱的空间分布和 ITER 可能输出的聚变功率、聚变中子产额、第一壁(产氚包层)之后的中子通量的蒙塔-卡罗中子输运(MCNP)计算,对氦冷却固体增殖剂中子学和产氚包层模块(NT-TBM-HCSB)的聚变中子诊断提出概念性设计,本设计提出用固定位置微型裂变室探测器和可移动封装薄箔活化分析系统测量中子倍增器之后、固体氚增殖剂中及其后的中子通量;用可移动天然金刚石探测器的紧凑型能谱仪测量中子能谱。
