First measurement of dE/dx with a GEM-based TPC
Keywords
time projection chamber | energy loss | gas electron multiplier | charged particle: particle identification | FOPI | energy resolution Time projection chamber | Gas electron multiplier | Specific energy loss | Particle identification | Exponentially modified Gaussian | FOPI
Abstract
In this work we present the first measurement of the specific energy loss (dE/dx) and an analysis of the resulting charged-particle identification (PID) capabilities of a large-scale TPC with GEM-based gas amplification. The data has been recorded inside the FOPI spectrometer at GSI, Germany, using reactions of 1.7 GeV/c pions impinging on a carbon target. In the specific energy loss spectrum clear bands for pions, kaons, protons and deuterons are observed. The specific energy loss resolution is studied as a function of the total particle momentum and as a function of the track length. It is found to be 15%, consistent with expectations.
