Compton-Pair Production Space Telescope (ComPair) for MeV Gamma-ray Astronomy

TL;DR

ComPair is a proposed space telescope designed to explore the under-studied MeV gamma-ray range with significantly improved sensitivity and resolution, capable of detecting both Compton scattering and pair production events.

Contribution

It introduces a new MIDEX-scale gamma-ray telescope that combines advanced detector technologies to achieve high sensitivity and resolution in the 200 keV to >500 MeV energy range.

Findings

Designed to be 20-50 times more sensitive than COMPTEL

Capable of detecting both Compton and pair-production events

Builds on technologies from successful space missions

Abstract

The gamma-ray energy range from a few hundred keV to a few hundred MeV has remained largely unexplored, mainly due to the challenging nature of the measurements, since the pi- oneering, but limited, observations by COMPTEL on the Compton Gamma-Ray Observatory (1991-2000). This energy range is a transition region between thermal and nonthermal processes, and accurate measurements are critical for answering a broad range of astrophysical questions. We are developing a MIDEX-scale wide-aperture discovery mission, ComPair (Compton-Pair Production Space Telescope), to investigate the energy range from 200 keV to > 500 MeV with high energy and angular resolution and with sensitivity approaching a factor of 20-50 better than COMPTEL. This instrument will be equally capable to detect both Compton-scattering events at lower energy and pair-production events at higher energy. ComPair will build on the her- itage of successful space missions including Fermi LAT, AGILE, AMS and PAMELA, and will utilize well-developed space-qualified detector technologies including Si-strip and CdZnTe-strip detectors, heavy inorganic scintillators, and plastic scintillators.