A GEM based TPC for beam monitoring

Abstract: In recent years Gas Electron Multipliers have proven to be reliable amplification stages at high beam rates, and can be used also in Time Projection Chambers. Our group developed a 1 dm$^3$ active volume double-GEM TPC, with spatial resolution of 50 $\mu m$ and 280 $\mu$m. Custom designed FPGA data acquisition system enables rate capability for about 100 kHz$\cdot$mm$^{-2}$, providing excellent track-by-track position and angular information, better than 0.1 mm and 1 mrad respectively. The wide dynamic range of the system enables identification from $^{4}$He up to $^{86}$Kr using ionization measurement. Two of these TPCs are planned to operate in tandem mode to filter off-time particles and to achieve a superior angular resolution.