We examine the performance of a TPC as a gamma-ray telescope above the pair-creation threshold. The contributions to the photon angular resolution are studied and their dependence on energy is obtained. The effective area per detector unit mass for such a thin detector is the conversion mass attenuation coefficient. The differential sensitivity for the detection of a point-like source is then derived. Finally, the measurement of track momentum from deflections due to multiple scattering is optimized. These analytical results are exemplified numerically for a few sets of detector parameters. TPCs show an impressive improvement in sensitivity with respect to existing pair-creation-based telescopes in the [MeV - GeV] energy range, even with the modest detector parameters of this study. In addition, gas TPCs allow an improvement in angular resolution of about one order of magnitude.
@article{arxiv.1211.1534,
title = {TPC in gamma-ray astronomy above pair-creation threshold},
author = {Denis Bernard},
journal= {arXiv preprint arXiv:1211.1534},
year = {2014}
}
Comments
This is the long version of a work presented at the 5th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma2012) July 9-13 2012, in Heidelberg, Germany. To appear in Nuclear Inst. and Methods in Physics Research, A