The Fluorescence Telescope on board EUSO-SPB2 for the detection of Ultra High Energy Cosmic Rays

TL;DR

The paper describes the development and capabilities of the Fluorescence Telescope on EUSO-SPB2, designed to detect ultra-high-energy cosmic rays from a balloon platform with a large field of view and advanced optics.

Contribution

It introduces the second-generation Fluorescence Telescope with Schmidt optics and a large focal surface, enhancing detection prospects from suborbital altitudes.

Findings

Telescope features Schmidt optics with 1-meter aperture.

Focal surface equipped with 6912-pixel MAPMT camera.

Designed for up to 100-day balloon flights for UHECR detection.

Abstract

The Fluorescence Telescope is one of the two telescopes on board the Extreme Universe Space Observatory on a Super Pressure Balloon II (EUSO-SPB2). EUSO-SPB2 is an ultra-long-duration balloon mission that aims at the detection of Ultra High Energy Cosmic Rays (UHECR) via the fluorescence technique (using a Fluorescence Telescope) and of Ultra High Energy (UHE) neutrinos via Cherenkov emission (using a Cherenkov Telescope). The mission is planned to fly in 2023 and is a precursor of the Probe of Extreme Multi-Messenger Astrophysics (POEMMA). The Fluorescence Telescope is a second generation instrument preceded by the telescopes flown on the EUSO-Balloon and EUSO-SPB1 missions. It features Schmidt optics and has a 1-meter diameter aperture. The focal surface of the telescope is equipped with a 6912-pixel Multi Anode Photo Multipliers (MAPMT) camera covering a 37.4 x 11.4 degree Field of Regard. Such a big Field of Regard, together with a flight target duration of up to 100 days, would allow, for the first time from suborbital altitudes, detection of UHECR fluorescence tracks. This contribution will provide an overview of the instrument including the current status of the telescope development.