A low mass time expansion chamber (TEC) has been developed to measure distributions of position and angle of the TRIUMF low energy surface muon beam used for the TWIST experiment. The experiment is a high precision measurement of muon decay and is dominated by systematic uncertainties, including the stability, reproducibility, and characterization of the beam. The distributions measured by two TEC modules are one essential ingredient of an accurate simulation of TWIST. The uncertainties, which are extracted through comparisons of data and simulation, must be known to assess potential systematic uncertainties of the TWIST results. The design criteria, construction, alignment, calibration, and operation of the TEC system are discussed, including experiences from initial beam studies. A brief description of the use of TEC data in the TWIST simulation is also included.
@article{arxiv.physics/0604107,
title = {Time expansion chamber system for characterization of TWIST low energy muon beams},
author = {J. Hu and G. Sheffer and Yu. I. Davydov and D. R. Gill and P. Gumplinger and R. S. Henderson and B. Jamieson and C. Lindsay and G. M. Marshall and K. Olchanski and A. Olin and R. Openshaw and V. Selivanov},
journal= {arXiv preprint arXiv:physics/0604107},
year = {2008}
}
Comments
v. 2, with corrections and revised figures. 23 pages, 16 figures, accepted for publication in Nuclear Inst. and Methods in Physics Research, A