The study of saturation effect of GEM detector for X-ray imaging

In our lab, an imaging detector prototype based on gas electron multiplier (GEM) was successfully designed and constructed. During the systematic response measurement of this device, an unexpected saturation phenomenon was highlighted. When the effective gas gain is increased, apparent saturation effect is observed. At high pressure, such as 2 atm or 3 atm, there is a similar phenomenon. Taking into account drift voltage, effective gas gain, area effect and resistive network, we now significantly diminish the saturation of the detector´s response and get some useful results.