  We present the operation of the recently introduced Photon Assisted Cascaded
Electron Multiplier (PACEM) in xenon at high pressure. The PACEM is a multi
step electron multiplier where the VUV scintillation produced in the electron
avalanches is used for signal propagation: the VUV scintillation produced in
the first element of the cascade induces the emission of photoelectrons from a
CsI photocathode placed on the top-surface of the second element. These
photoelectrons are further multiplied, via charge avalanche. A metallic mesh
electrode placed between the first and the second elements of the cascade
completely blocks the charge transfer between them. Optical gains of 103 were
achieved in xenon at atmospheric pressure, dropping to 25 at 3.3 bar, for
applied voltages of 700 and 1100 V, respectively. Taking into account the
subsequent charge multiplication, total gains are higher than those obtained
with a triple GEM and double THGEM.
