Recent investigations of cascaded GEM and MHSP detectors

We present results from our recent investigations on detectors comprising cascaded gas electron multipliers (GEMs) and cascaded GEMs with microhole and strip plate (MHSP) multiplier as a final amplification stage. We discuss the factors governing the operation of these fast radiation-imaging detectors, which have single-electron sensitivity. The issue of ion-backflow and ion-induced secondary effects is discussed in some detail, presenting ways for its suppression. Applications are presented in the fields of photon imaging in the ultraviolet-to-visible spectral range as well as X-ray and neutron imaging.