Tracker-In-Calorimeter (TIC): a calorimetric approach to tracking gamma rays in space experiments

TL;DR

This paper introduces the Tracker-In-Calorimeter (TIC), a novel gamma-ray tracking method that uses a segmented calorimeter to sample electromagnetic showers, addressing conflicting detector requirements in space-based cosmic ray experiments.

Contribution

The paper presents a new TIC design that combines calorimetric sampling with gamma-ray tracking, validated through simulations and prototype tests.

Findings

Effective gamma-ray tracking demonstrated in simulations

Prototype tests confirm feasibility of the TIC approach

Potential for improved angular resolution in space detectors

Abstract

A multi-messenger, space-based cosmic ray detector for gamma rays and charged particles poses several design challenges due to the different instrumental requirements for the two kind of particles. Gamma-ray detection requires layers of high Z materials for photon conversion and a tracking device with a long lever arm to achieve the necessary angular resolution to separate point sources; on the contrary, charge measurements for atomic nuclei requires a thin detector in order to avoid unwanted fragmentation, and a shallow instrument so to maximize the geometric factor. In this paper, a novel tracking approach for gamma rays which tries to reconcile these two conflicting requirements is presented. The proposal is based on the Tracker-In-Calorimeter (TIC) design that relies on a highly-segmented calorimeter to track the incident gamma ray by sampling the lateral development of the electromagnetic shower at different depths. The effectiveness of this approach has been studied with Monte Carlo simulations and has been validated with test beam data of a detector prototype.