Master thesis: Measures to Improve the Light Yield Uniformity of Tapered PWO Crystals
by
Olle Lundberg(Stockholm University)
→
Europe/Stockholm
A3:1003
A3:1003
Description
PANDA is a next generation hadron physics detector that will operate at FAIR.
The high luminosity and the well-defined beam momentum for a wide energy region, between
1.5 and 15 GeV, means that PANDA can be used to investigate a wide range of hadron physics
in order to study open questions within Quantum Chromodynamics.
The light yield non-uniformity of the barrel crystals at the electromagnetic
calorimeter of the PANDA detector stands for a large contribution to relative
resolution of these crystals. In this thesis several methods using differential
wrappings have been used to improve the light yield uniformity. It is shown
that methods using absorbing wrappings can be used to improve the light yield
uniformity of a barrel crystal of type 2 by a factor 3. Calculations show that for photon
energies above approximately 50 MeV the resolution is improved.
For expample, the relative resolution at 1280 MeV goes from 2.3% to 1.2% using 19 mm
of tape wrapped around the front of the crystal. However, the decreased light yield
that is a result of these methods leads to a slightly lower resolution at the lowest photon energies.
Outlines are drawn up for future work and future use of this thesis.
