Precise beta-branching-ratio measurements are required in order to determine ft-values as a part of our program to test the Electroweak Standard Model via unitarity of the Cabibbo-Kobayashi-Moskawa matrix. For the measurements to be useful in this test, their precision must be close to 0.1 %. In a branching-ratio measurement, we position the radioactive sample between a thin plastic scintillator used to detect beta-particles, and a HPGe detector for gamma-rays. Both beta singles and beta-gamma coincidences are recorded. Although the branching ratio depends most strongly on the HPGe detector efficiency, it has some sensitivity to the energy dependence of the beta-detector efficiency. We report here on a study of our beta-detector response function, which used Monte Carlo calculations performed by the Geant4 toolkit. Results of the simulations are compared to measured beta-spectra from several standard beta-sources.
@article{arxiv.0806.0886,
title = {The use of Geant4 for simulations of a plastic beta-detector and its application to efficiency calibration},
author = {V. V. Golovko and V. E. Iacob and J. C. Hardy},
journal= {arXiv preprint arXiv:0806.0886},
year = {2008}
}
Comments
9 pages, 8 figures; preprint submited to Nucl. Instr. and Meth. A, May 2008