A voltage-controlled Gas Electron Multiplier (GEM) can be used to block the re-injection of positive ions in large volume Time Projection Chambers (TPC). Through an accurate choice of proper geometry, gas filling and external fields it is possible to obtain a sufficient level of electron transmission at very low GEM voltages (Gating GEM) despite the degradation of energy resolution due to the loss of primary electrons. The addition of a pre-amplification GEM in front of the Gating GEM causes an improvement in energy resolution while keeping the ion feedback at the level of primary ionization. The measurements show that a small pulse of about 40 V completely closes the gate, stopping the ions produced in the amplification stage. © 2010 IOP Publishing Ltd and SISSA
Croci, G., Alfonsi, M., Duarte Pinto, S., Ropelewski, L., Sauli, F., Villa, M., et al. (2010). Gas Electron Multiplier (GEM) application for Time Projection Chamber (TPC) gating. JOURNAL OF INSTRUMENTATION, 5(3) [10.1088/1748-0221/5/03/P03001].
Gas Electron Multiplier (GEM) application for Time Projection Chamber (TPC) gating
CROCI, GABRIELEPrimo
;
2010
Abstract
A voltage-controlled Gas Electron Multiplier (GEM) can be used to block the re-injection of positive ions in large volume Time Projection Chambers (TPC). Through an accurate choice of proper geometry, gas filling and external fields it is possible to obtain a sufficient level of electron transmission at very low GEM voltages (Gating GEM) despite the degradation of energy resolution due to the loss of primary electrons. The addition of a pre-amplification GEM in front of the Gating GEM causes an improvement in energy resolution while keeping the ion feedback at the level of primary ionization. The measurements show that a small pulse of about 40 V completely closes the gate, stopping the ions produced in the amplification stage. © 2010 IOP Publishing Ltd and SISSAI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.