THGEM operation in high pressure Ne/CF4

THGEM investigations in Ne mixtures focused so far atmospheric pressures. However, the applications of GPMs operating at cryogenic temperatures result in THGEM operation in neon mixtures with gas densities higher than those at atmospheric pressure at room temperature. In addition, X-ray and charged particle detection would benefit from higher gas densities. In this work we studied the room temperature operation of Single and Double-THGEM detectors in Ne/CF4 gas mixtures with pressures up to 3bar. Measurements with soft X-rays obtained gains of 7 × 104 and 3 × 104 with a Double-THGEM, in 1bar and 3bar of Ne/CF4 (95:5), respectively. For Ne/CF4 (90:10), gains of 1 × 105 and 4 × 104, were obtained with the Double-THGEM. It is shown that the maximum achievable gain is not significantly affected by the increase of gas pressure. Energy resolution for 5.9keV X-rays was of the order of 23%. In this work, we also report on the effect of our getter-based gas purification system and the consequent gas impurity on the THGEM's performance. We show that without purification the operation voltages of the THGEM detector gradually increase with time, requiring higher voltages to reach a given gain, while the maximum achieved gain did not change.