TWIST Summer Student: Clay Lindsay
The TRIUMF Weak Interaction Symmetry Test, or TWIST, seeks to study
polarized muon-to-positron decays to high precision in order to test
symmetries in the weak interaction. TWIST's 2004 data run included
the addition of a sub-detector to the main apparatus in order to
precisely characterize the muon beam: a time expansion chamber (TEC).
On first analysis of this data run, the time expansion chamber's
response produced unexpected results. The response expectations
assumed a constant electric field within the TEC's modules. A
detailed study of the electric field within the TEC is necessary to
properly understand and preict the TEC's response for future data
runs. This report describes the TEC geometry, a simulation of that
geometry, and a numerical solution for the electric field inside the
modules. Geometry modifications are explored and recommendations are
made with regard to these modifications.