Author/Authors :
Maia، نويسنده , , J.M. and Mِrmann، نويسنده , , D. and Breskin، نويسنده , , A. and Chechik، نويسنده , , Sheila R. M. Veloso، نويسنده , , J.F.C.A. and dos Santos، نويسنده , , J.M.F.، نويسنده ,
Abstract :
We report on avalanche-ion back-flow measurements in the novel Micro-Hole and Strip-Plate (MHSP) multiplier and in gaseous photomultipliers comprising Gas Electron Multipliers (GEMs) followed by an MHSP. In a 3-GEMs/MHSP photomultiplier with reflective photocathode, avalanche-ion back-flow fraction of ∼7% and ∼2% were recorded for respective effective gains of 107 and 106, in Ar/CH4 (95/5) at 760 Torr. This is about one order of magnitude reduction in ion back-flow compared to the best values measured in 4-GEMs photomultiplier at the same gain. We describe the mode of operation of the MHSP and explain its ion back-flow reduction features.
Keywords :
Gaseous photomultipliers , Ion back-flow , MHSP , GEM , Gas avalanche electron multipliers
