A new imaging device based on UV scintillators and a large area gas photomultiplier

Abstract A new type high spatial resolution radiation detector based on a UV scintillator+a UV imaging gas photomultiplier is presented. The prototype UV detector consists of a 10 cm×10 cm μPIC, 2 GEMs and a semitransparent CsI photocathode deposited on a MgF 2 window. The effective photo-sensitive area is ϕ 34 mm and the readouts are 400 μm pitch strips. A newly developed 20 mm size LaF 3 (Nd) crystal which emits 172 nm photons is coupled to the detector for the first step. The detector was tested in pulse mode operation with 5.5 MeV α particles from 241 Am. The single photoelectrons were successfully detected and the images of the crystal shape were clearly obtained.