p/${\pi^+}$ response of single layer THGEM detector in Ar/3%iC$_4$H$_{10}$

In this work, we study the response of a single layer Thick Gaseous Electron Multiplier (THGEM) detector to p/pi(+) at the E3 line of the Beijing Test Beam Facility. The THGEM detector drift gap used in this study is 4 mm, and the gain of the detector operated in Ar+3% iC(4)H(10) is about 2000. p/pi(+) particles at momenta between 500 MeV/c and 1000 MeV/c are distinguished by a Time Of Flight system. Our results show that at the measured momenta, detection efficiencies for p are from 93% to 99%, and for pi(+) in the range of 82%-88%. Meanwhile, simple Geant4 simulations also have been done, and are consistent with the amplitude spectra of the beam test results. We preliminarily study the feasibility of the THGEM detector as a sampling element for a Digital Hadronic Calorimeter (DHCAL), which may provide support for the possible application of a THGEM detector in the Circular Electron Positron Collider (CEPC) HCAL.