a design study for a cobra upgrade to - Institut für Kern- und ...

5.1 Monte Carlo studies for the upgrade design 61
/CsI/detector/ny 1
/CsI/detector/nz 1
/CsI/detector/housingfinish 6
/CsI/detector/reflectivity 0.98
/CsI/detector/qe 7
Figure 5.3: Visualisation of the constructed CsI crystal geometry. a)
5x5x20 cm 3 crystal with attached lightguide and APD. b) Crystal with
round PMT. c) Crystal with 4 lightguides and APDs. d) Si-PMT with
only 100 pixels, attached via a light guide to the crystal.
The glass plate is placed directly at the crystal surface and the Al layer
is placed behind the glass plate. It will always be placed in the middle
of the crystal side, multiple readout devices are placed regularly on the
surface. Si-PMTs are realised as one device with quantum efficiencies,
taking the dead layers between the pixels into consideration. The simulation
of pixelated Si-PMT is also possible, by setting the corresponding
pixel number and size. The command /CsI/detector/mppc enables
a placement side by side in the middle of the crystal side.
The command /CsI/detector/lightguide places one or more
light guides between the crystal and the glass. The front side of the
light guide will decrease with an angle of 60 ◦ towards the readout de-