New trapezoid-shaped Frisch-grid ionization chamber for low-energy particle measurements
Tianli Qiu (Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China, School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China); Yuansheng Yang (Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China, School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China); Xiaohua Yuan (Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China, School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China); Peng Ma (Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China, School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China); Meng Li (Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China, School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China); et al - Show all 22 authors
A new trapezoid-shaped Frisch-grid ionization chamber (TFG-IC) has been built as a part of a $$\varDelta {E}-E$$ telescope system for the detection and identification of charged particles at energies down to a few MeV. To study the effect of the drift electric field uniformity, two types of sealed windows, namely a pair of SSA (split-strip aluminized mylar film) and a pair of DSA (double-sided aluminized mylar film) sealed windows have been investigated. The detector’s performances were studied using a standard $$^{241}$$ Am source at different gas pressures, and the total energy-deposit resolution achieved is about 1.1%(FWHM). The $$\varDelta {E}-E$$ telescope, which was composed of TFG-IC and a DSSSD (double-sided silicon strip detector), has been tested using a three-component $$\alpha $$ source and the $$^{241}$$ Am source under laboratory conditions. The results show that the energy resolution with the SSA sealed windows which provide uniform drift electric field has a smaller fluctuation than that with the DSA ones; the fluctuations are about 1% and 4% for the former and the latter, respectively. Simulations using the COMSOL software also confirmed the electric-field distortion at the edge of the detector with the DSA windows. A correlation curve between energy resolution and energy deposit of charged particles at various gas pressures and for two gas species is derived for TFG-IC with the SSA sealed windows using the measurement with the $$^{241}$$ Am source. Incorporating the above results, we performed Monte Carlo simulations to evaluate the particle-identification capability of the telescope. The results show that the telescope can be extended to the identification of low-energy particles.