The development of a gas-filled time-of-flight detector

A gas-filled time-of-flight (GF-TOF) detector system for isobaric identification has been developed at the AMS facility of the China Institute of Atomic Energy (CIAE). The newly built GF-TOF detector was tested by using a 36Cl standard sample (36Cl/Cl = 2.88 × 10−11) with the 36Cl ion energies of 64, 49 and 33 MeV. Time resolutions of 350 ps, 580 ps and 920 ps were obtained for 64, 49 and 33 MeV 36S, respectively, without gas. 36Cl and 36S particles were successfully separated in the TOF spectra from the GF-TOF detector at the three different incident energies. The dependence of time resolution and separation power of GF-TOF method on the incidence energy and the residual energy is discussed. The comparison of separation power for isobars between the GF-TOF method and the ΔE–E method is described. A combination of GF-TOF method and ΔE–E method may further improve the separation power for isobars. The results show that the sensitivity for 36Cl AMS measurements is 10−14 at the energy of 33 MeV. Some results obtained with the GF-TOF method are given.