Balloon flight of the Advanced Scintillator Compton Telescope (ASCOT)
Abstract
The Advanced Scintillator Compton Telescope (ASCOT) is a new medium-energy gamma-ray Compton telescope addressing the existing need for a mission in the medium-energy gamma-ray energy range of 0.4 - 20 MeV. ASCOT is a prototype built on the legacy of COMPTEL instrument onboard CGRO. It uses commercially available high-performance scintillators, such as Cerium Bromide (CeBr3) and p-terphenyl in conjunction with Silicon Photomultipliers (SiPM) which are compact readout devices to improve the instrument response. Together with these advancements in hardware, ASCOT also uses the Time-of-Flight background rejection, an important tool for effective imaging in this energy range. ASCOT was developed with the goal of imaging the Crab Nebula at MeV energies during a high-altitude balloon flight. The balloon payload was launched by NASA from Palestine (TX) on 5th July 2018. It was a successful flight with ASCOT operating stably and observing the Crab for ~5 hours from an altitude of 120,000 ft. We present here the development of the instrument and a preliminary look at the flight data. Pre-flight calibrations and simulations results are also shown, based on which we expect a ~4.5 sigma detection of the Crab in the 0.2 - 2 MeV band. The results from ASCOT will be pivotal in demonstrating an improvement in the energy, timing, and position resolution using this advanced technology.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1710982S