Development of a cosmic ray oriented trigger for the fluorescence telescope on EUSO-SPB2

TL;DR

EUSO-SPB2 aims to detect ultra-high energy cosmic rays from near space using a novel trigger algorithm for its fluorescence telescope, with simulations indicating promising performance for future space-based cosmic ray observations.

Contribution

A new hardware-level trigger algorithm for fluorescence telescopes has been developed, optimized for detecting UHECRs in near-space conditions.

Findings

Simulations show the trigger can effectively identify UHECR events.

The trigger design accounts for detector limitations and background noise.

EUSO-SPB2 is positioned to make pioneering near-space UHECR observations.

Abstract

The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2), in preparation, aims to make the first observations of Ultra-High Energy Cosmic Rays (UHECRs) from near space using optical techniques. EUSO-SPB2 will prototype instrumentation for future satellite-based missions, including the Probe of Extreme Multi-Messenger Astrophysics (POEMMA) and K-EUSO. The payload will consist of two telescopes. The first is a Cherenkov telescope (CT) being developed to quantify the background for future below-the-limb very high energy (E>10 PeV) astrophysical neutrino observations, and the second is a fluorescence telescope (FT) being developed for detection of UHECRs. The FT will consist of a Schmidt telescope, and a 6192 pixel ultraviolet camera with an integration time of 1.05 microseconds. The first step in the data acquisition process for the FT is a hardware level trigger in order to decide which data to record. In order to maximize the number of UHECR induced extensive air showers (EASs) which can be detected, a novel trigger algorithm has been developed based on the intricacies and limitations of the detector. The expected performance of the trigger has been characterized by simulations and, pending hardware verification, shows that EUSO-SPB2 is well positioned to attempt the first near-space observation of UHECRs via optical techniques.