Recent investigations of cascaded GEM and MHSP detectors

We present results from our recent investigations on detectors comprising cascaded gas electron multipliers (GEM) and cascaded GEMS with micro-hole and strip (MHSP) electrodes as a final amplification stage. We discuss the factors governing the operation of these fast radiation-imaging detectors, which have single-charge 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 UV-to-visible spectral range as well as x-ray and neutron imaging.