Author:
Mo Yixiang,Tang Jianfeng,Fan Zhongkai,Hu Tao,Lin Fen,Xie Ruomei,Yuan Shuai,Liu Shuaibin,Yuan Hongzhi,Tan Yanliang
Abstract
Abstract
Developing an ultra-high sensitivity electrostatic
collection radon monitor benefits the scientific experiments of
China Jinping Underground Laboratory. Here, a one cubic meter
electrostatic collection vessel with a multi-layer hemispherical
metal grid was designed to increase the collection efficiency of
positively charged Po-218 ions. The 3D model of the giant
electrostatic collection vessel was constructed using the COMSOL
Multiphysics simulation software, and the potential and electric
field distributions in the vessel were simulated. Numerical
simulation results were obtained according to the different radii
and voltages applied to the grid. The electric field between the
vessel wall and grid, between two grids, and between the grid and
surface of the PIPS detector must be set uniformly to reduce the
collection time of the positively charged Po-218 ions. Simulation
results showed that setting a charged metal grid in the vessel can
optimize the electric field distribution, and setting a two-layer
charged metal grid in the giant vessel can further increase the cost
performance. The average collection times of the electrostatic
collection vessel with the two-layer grid along the vertical and
oblique lines approximately 15% and 13% of that without the
grid. The rates of positively charged Po-218 ions that could pass
through the one and two-layer metal grids were 86.78% and
50%. Optimizing the electric field can greatly increase the
sensitivity of radon monitors and reduce the humidity restrictions.
Subject
Mathematical Physics,Instrumentation