UC Riverside

A prototype balloon-borne telescope is being constructed for gamma-ray observations in the MeV energy range. The Tracking and Imaging Gamma-Ray Experiment (TIGRE) uses multi-layers of thin silicon detectors to track and measure the energy losses of Compton recoil electrons. When combined with the direction and energy of the Compton scattered gamma-ray a unique incident direction for each photon event is determined. This facilitates background rejection, improved sensitivity and image reconstruction. The converter/tracker also serves as an electron-positron pair detector for gamma-rays up to 100 MeV. The initial continental US flight will be used to determine the sub-orbital atmospheric backgrounds and search for polarized gamma-emission for the Crab pulsar. Longer southern hemisphere flights with an enhanced instrument will map out the Al-26 emissions from the galactic center region. (C) 2003 Elsevier B.V. All rights reserved.