The 511-CAM Mission: A Pointed 511 keV Gamma-Ray Telescope with a Focal Plane Detector Made of Stacked Transition Edge Sensor Microcalorimeter Arrays

TL;DR

The 511-CAM mission proposes a high-resolution gamma-ray telescope using stacked TES microcalorimeters and focusing optics to better understand the origin of 511 keV emission from the galactic center.

Contribution

It introduces a novel 511 keV gamma-ray telescope concept combining focusing optics with TES microcalorimeter arrays for improved resolution.

Findings

Projected 511 keV energy resolution of 390 eV FWHM or better.

Improves performance by at least a factor of 11 over current Ge-based Compton telescopes.

Potential to identify point sources and measure plasma velocities in the galactic center.

Abstract

The 511 keV gamma-ray emission from the galactic center region may fully or partially originate from the annihilation of positrons from dark matter particles with electrons from the interstellar medium. Alternatively, the positrons could be created by astrophysical sources, involving exclusively standard model physics. We describe here a new concept for a 511 keV mission called 511-CAM (511 keV gamma-ray CAmera using Micro-calorimeters) that combines focusing gamma-ray optics with a stack of Transition Edge Sensor (TES) microcalorimeter arrays in the focal plane. The 511-CAM detector assembly has a projected 511 keV energy resolution of 390 eV Full Width Half Maximum (FWHM) or better, and improves by a factor of at least 11 on the performance of state-of-the-art Ge-based Compton telescopes. Combining this unprecedented energy resolution with sub-arcmin angular resolutions afforded by Laue lens or channeling optics could make substantial contributions to identifying the origin of the 511 keV emission by discovering and characterizing point sources and measuring line-of-sight velocities of the emitting plasmas.