# Design and construction of a high-energy photon polarimeter

## TL;DR

This paper presents the design and construction of a high-energy photon polarimeter that measures photon beam polarization via triplet production and silicon strip detectors, achieving an analyzing power of 0.2 with low systematic uncertainty.

## Contribution

It introduces a novel high-energy photon polarimeter utilizing triplet production and silicon detectors, with detailed design and performance evaluation.

## Key findings

- Analyzing power of about 0.2 with a 1.5% systematic uncertainty.
- Effective measurement of photon polarization using triplet production.
- Integration with a pair spectrometer enhances measurement accuracy.

## Abstract

We report on the design and construction of a high-energy photon polarimeter for measuring the degree of polarization of a linearly-polarized photon beam. The photon polarimeter uses the process of pair production on an atomic electron (triplet production). The azimuthal distribution of scattered atomic electrons following triplet production yields information regarding the degree of linear polarization of the incident photon beam. The polarimeter, operated in conjunction with a pair spectrometer, uses a silicon strip detector to measure the recoil electron distribution resulting from triplet photoproduction in a beryllium target foil. The analyzing power $\Sigma_A$ for the device using a 75 $\rm{\mu m}$ beryllium converter foil is about 0.2, with a relative systematic uncertainty in $\Sigma_A$ of 1.5%.