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

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 MgF2 window. The effective photo-sensitive area is ϕ34 mm and the readouts are 400 μm pitch strips. A newly developed 20 mm size LaF3(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 241Am. The single photoelectrons were successfully detected and the images of the crystal shape were clearly obtained.