Research On The Performance Of Neutron Thick Gas Electron Multiplier Applied To Neutron Detection

Neutron is widely used owing ro the electrically neutral and the advantage of magnetic moment,for example,neutron activation analysis technology,neutron exploration technology,neutron radiography and so on.So the application of neutrons is widely used in all fields.With the development of the establishment and development of the high flux neutron source in the world,the flux of the neutron source is as high as10⁸⁹n/cm²?s.Detectors of the ³He proportional counter tube is unable to meet the need for high flux neutron source.Gas Electron Multiplier?GEM?neutron detector which has been an international hotspot has the advantages of high counting rate,good spatial resolution and low prices.Neutrons are detected by using the coated boron neutron conversion layer.Based on the above research background,this paper focuses on the simulation and experiment on the performance of neutron THick GEM detector.The simulation software includes:Ansys,Garfield++,Geant4.Garfield++is used to simulate the electric field of the center of nTHGEM,the collection and extraction effiency to determine the electric field of the drift and induct region.The electric field of drift region?nTHGEM and induct region is respectively determined at 1³kV/cm,900-1100V and 2⁴kV/cm.The effective gain variation curve of the detector under different gas composition is calculated,and the higher gain can be obtained by using neon and carbon dioxide.The effective gain of the detector with different ratio of argon and carbon dioxide is calculated.When the content of carbon dioxide is less,the gain of the detector is higher,but the transverse diffusion of the electron is wider.By changing the size of the nTHGEM film to rich a high detector gain,when the rim size is smaller,the detector is easy to reach high gain.Then the signal width of X ray is simulated.The signal width of the electric field intensity in different induct area is calculated,and the width of the signal is eventually stabilized at about 55ns with the increase of the electric field intensity,and the transverse diffusion in gas is 1.0 millimeter.The calculation of the angle and the energy distribution of the emitted particles are calculated by the simulation of the nuclear reaction between the neutron and the boron-10.The transverse diffusion of a single neutron is calculated as 1.8 millimeter,and the width of the neutron signal is maintained at about 120ns.In the experiment part,the imaging experiment and beam test are carried out by using larger area detector.The detector is a square which the side legth is 200 millimeter.The position resolution of the detector was tested,and the position resolution of the detector is 628millimeter which meets the target of the design of the detector.