First sensitivity limits of the ALPS TES detector

TL;DR

This paper reports the initial sensitivity limits of the ALPS TES detector for 1064 nm photons, highlighting the main sources of dark counts and improvements over previous detectors.

Contribution

It introduces the ALPS TES detector system and identifies thermal photons as the main dark count source, demonstrating improved performance over ALPS I.

Findings

Thermal photons from room temperature surfaces dominate dark counts.

The ALPS TES detector shows improved sensitivity compared to ALPS I.

First sensitivity limits of the ALPS TES detector are established.

Abstract

The Any Light Particle Search II (ALPS II) requires a sensitive detection of 1064 nm photons. Thus, a low dark count rate (DC) and a high detection efficiency (DE) is needed. ALPS has set up a transition-edge sensor (TES) detector system, namely the ALPS TES detector. It is found that thermal photons from room temperature surfaces are the main contribution of dark counts for 1064 nm photon signals. Furthermore, the current setup of the ALPS TES detector shows an improvement compared to using the ALPS I detector.