Speaker
Dr
Ilhan Tapan
(Uludag Universitesi)
Description
The charge carriers in the detector volume created in the gas
amplification process cause a space charge effect. The fluctuation
in gas amplification process is one of the main factor in the energy
resolution of proportional counters. At low bias voltages only a
very small number of charge carriers are generated and so the space
charge effect is negligibly low. However, as bias voltage increases
so does the gas amplification factor and the number of the secondary
charge carriers grows, reducing the electric field strength between
space charges and the anode wire.
In the present work, a Monte Carlo simulation code [1] has been used
in order to investigate the influence of space charge effect on the
gas gain and its fluctuation for different operation voltages and
gas mixture ratios. In order to compare simulation and experimental
results, the simulation code has been applied for the well-known
ALEPH Inner Tracking Detector geometry whick is a non-uniform field
argon-based gas detector that is operated in a proportional mode.
The results show that under normal operation conditions such space
charge effect can cause significant change in the relative variance
of the gain distribution started by a single primary electron
generated in the different position.
References
[1] - I. TAPAN and N. DEMIR, Simulation of gain fluctuation for non-
uniform field argon based gas detector, Nuclear Instruments and
Methods in Physics Research A 525 (2004)p53
Primary author
Mrs
Nilgun Demir
(Uludag Universitesi)
Co-author
Dr
Ilhan Tapan
(Uludag Universitesi)
