The characteristics of signals from nTPC and its application in background suppression

Neutron-TPC (nTPC) is a under-developing fast neutron spectrometer based on GEM-TPC. By measuring energy deposition and scattering angles of protons recoiled by incident neutrons, one can deduce the neutron spectrum. Except for protons, some other particles, such as ¹²C, ⁴⁰Ar, gamma and muon, will also enter the effective volume of TPC and bring in background. By analyzing the characteristics of signals, one can find the differences among different particles and suppress background by setting proper cut thresholds. By Geant4 simulation, this method has been confirmed.