Detecting High-Energy Cosmic Ray Electrons With CREST (the Cosmic Ray Electron Synchrotron Telescope).

Abstract

The Cosmic Ray Electron Synchrotron Telescope (CREST) was a balloon-borne detector designed to measure the high-energy cosmic ray all-electron energy spectrum. It utilized a novel indirect technique proposed in 1983 by Stephens and Balasubrahmanyan to detect electrons by means of the synchrotron radiation they produce while interacting with the Earth’s magnetic field. CREST took data during a 10-day circum-anti-polar flight originating near McMurdo Station, Antarctica from December 2011-January 2012. In this work I describe the instrument’s design, assembly, operation, detection scheme, launch, flight and recovery, as well as my original work on displaying and analyzing the flight data. In particular I describe a novel detection method combining direct detection of the primary electron and indirect detection of the electron’s secondary synchrotron photons. Further I characterize CREST’s ability to determine the momentum direction of signal electrons, and outline a method for determining the charge of primary leptons making use of that pointing capability. I also propose an improved detector surface configuration suitable for future CREST-like detectors which greatly reduces sensitivity to the ubiquitous charged particle background.