Prototype Development and Calibration of the CUbesat Solar Polarimeter (CUSP)
Abstract
The space-based CUbesat Solar Polarimeter (CUSP) mission aims to measure the linear polarization of solar flares in the hard X-ray band by means of a Compton scattering polarimeter. CUSP will allow to study the magnetic reconnection and particle acceleration in the flaring magnetic structures of our star with its unprecedented sensitivity to solar flare polarization. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop new CubeSat missions. It has been proposed as a constellation of a two Cubesat mission to monitor the Sun for Space Weather, and will proceed with a single-satellite asset in its baseline implementation. In the frame of CUSP's Phase B study, that started in December 2024 for a 1-year period, we present the development status of this dual-phase polarimeter. Preliminary laboratory results using two chains of acquisition will be discussed. The first chain of acquisition, based on the Hamamatsu R7600 multi-anode photomultiplier tubes coupled to plastic scintillator bars and read out by the MAROC-3A ASIC, is used to detect the Compton scattering of incoming photons. On the other hand, GAGG crystals coupled to avalanche photo-diodes with a readout based on the SKIROC-2A ASIC are used to absorb the scattered photons. By reconstructing the azimuthal scattering direction for many incoming photons, one can infer the linear polarization degree and angle of the source. We will discuss the calibration results obtained with our prototype detector by using well-known radioactive isotopes, allowing us to assess the performances of our detector over the full 25-100 keV energy range.
Cite
@article{arxiv.2508.00642,
title = {Prototype Development and Calibration of the CUbesat Solar Polarimeter (CUSP)},
author = {Nicolas De Angelis and Abhay Kumar and Sergio Fabiani and Ettore Del Monte and Enrico Costa and Giovanni Lombardi and Paolo Soffitta and Andrea Alimenti and Riccardo Campana and Mauro Centrone and Giovanni De Cesare and Sergio Di Cosimo and Giuseppe Di Persio and Alessandro Lacerenza and Pasqualino Loffredo and Gabriele Minervini and Fabio Muleri and Paolo Romano and Alda Rubini and Emanuele Scalise and Enrico Silva and Davide Albanesi and Ilaria Baffo and Daniele Brienza and Valerio Campamaggiore and Giovanni Cucinella and Andrea Curatolo and Giulia de Iulis and Andrea Del Re and Vito Di Bari and Simone Di Filippo and Immacolata Donnarumma and Pierluigi Fanelli and Nicolas Gagliardi and Paolo Leonetti and Matteo Merge and Dario Modenini and Andrea Negri and Daniele Pecorella and Massimo Perelli and Alice Ponti and Francesca Sbop and Paolo Tortora and Alessandro Turchi and Valerio Vagelli and Emanuele Zaccagnino and Alessandro Zambardi and Costantino Zazza},
journal= {arXiv preprint arXiv:2508.00642},
year = {2025}
}
Comments
7 pages, 4 figures, SPIE Optics+Photonics 2025 proceeding