MHSP in reversed-biased operation mode for ion blocking in gas-avalanche   multipliers
  We present recent results on the operation of gas-avalanche detectors comprising a cascade of gas electron multipliers (GEMs) and Micro-Hole and Strip Plates (MHSPs) multiplier operated in reversed-bias (R-MHSP) mode. The operation mechanism of the R-MHSP is explained and its potential contribution to ion-backflow (IBF) reduction is demonstrated. IBF values of 4E-3 were obtained in cascaded R-MHSP and GEM multipliers at gains of about 1E+4, though at the expense of reduced effective gain in the first R- MHSP multiplier in the cascade. 
J.F.C.A. Veloso, F. Amaro, J.M. Maia, A.V. Lyashenko, A. Breskin, R.   Chechik, J.M.F. dos Santos, O. Bouianov, M. Bouianov