论文标题
基于钒的中子梁监测器
Vanadium-based neutron Beam Monitor
论文作者
论文摘要
原型的原型寄生热中子束监测器基于来自薄的天然钒箔和标准$^3 $成比例计数器的各向同性中子散射，概念化，设计，模拟，校准和委托。旨在传递源自脉冲来源的最高集成中子通量的欧洲散布来源目前正在瑞典隆德建造。为了在复杂的光束线上提供可靠的监控，在ESS中子梁中永久放置在ESS中子束中的光束监测器的要求列表触发了调查基于气聚的中子束监测器的努力，以提供可靠的衰减，较低的响应，在范围内的范围内的范围内，范围内的范围内，均值范围内的范围内，可以实现所有可能性，并且可以实现所有范围内的范围内，并且可以实现所有范围。在德国柏林的Helmholtz-Zentrum的V17和V20中子束线上，在德国柏林的V17和V20中子束线上研究了基于散射的原型，该原型采用了天然的钒箔和标准的$^3 $成比例的计数器进行了调查，并在$^3 $的几种不同的几何配置中进行了$^3 $的分数柜台。响应线性成功证明了从0.04 mm到3.15 mm的箔厚度。对于0.04毫米和0.125 mm的箔，证明了热中子的衰减低于1％。模拟了用于实验的几何形状，以实现绝对通量校准，并确定原型各种设计的效率范围。将梁监视器原型的操作通量极限作为背景辐射和原型几何形状的依赖性建立。此处证明的原型监视器可用于中子通量，范围从$ 10^3-10^{10} $ n/s/cm $ $^2 $。
A prototype quasi-parasitic thermal neutron beam monitor based on isotropic neutron scattering from a thin natural vanadium foil and standard $^3$He proportional counters is conceptualized, designed, simulated, calibrated, and commissioned. The European Spallation Source designed to deliver the highest integrated neutron flux originating from a pulsed source is currently under construction in Lund, Sweden. The effort to investigate a vanadium-based neutron beam monitor was triggered by a list of requirements for Beam Monitors permanently placed in the ESS neutron beams in order to provide reliable monitoring at complex beamlines: low attenuation, linear response over a wide range of neutron fluxes, near to constant efficiency for neutron wavelengths in a range of 0.6-10 Å, calibration stability and the possibility to place the system in vacuum are all desirable characteristics. The scattering-based prototype, employing a natural vanadium foil and standard $^3$He proportional counters, was investigated at the V17 and V20 neutron beamlines of the Helmholtz-Zentrum in Berlin, Germany, in several different geometrical configurations of the $^3$He proportional counters around the foil. Response linearity is successfully demonstrated for foil thicknesses ranging from 0.04 mm to 3.15 mm. Attenuation lower than 1% for thermal neutrons is demonstrated for the 0.04 mm and 0.125 mm foils. The geometries used for the experiment were simulated allowing for absolute flux calibration and establishing the possible range of efficiencies for various designs of the prototype. The operational flux limits for the beam monitor prototype were established as a dependency of the background radiation and prototype geometry. The herein demonstrated prototype monitors can be employed for neutron fluxes ranging from $10^3-10^{10}$ n/s/cm$^2$.
