Compton Polarimeter Prototype for the CUbesat Solar Polarimeter (CUSP) mission

@misc{angelis2026compton,
  title = {{Compton Polarimeter Prototype for the CUbesat Solar Polarimeter (CUSP) mission}},
  author = {Nicolas De Angelis and Andrea Alimenti and Riccardo Campana and Mauro Centrone and Giovanni De Cesare and Ettore Del Monte and Sergio Di Cosimo and Enrico Costa and Sergio Fabiani and Abhay Kumar and Pasqualino Loffredo and Giovanni Lombardi and Gabriele Minervini and Fabio Muleri and Paolo Romano and Alda Rubini and Enrico Silva and Paolo Soffitta and Giovanni Cucinella and Vito Di Bari and Simone Di Filippo and Andrea Negri and Massimo Perelli and Davide Albanesi and Valerio Campamaggiore and Giulia de Iulis and Andrea Del Re and Paolo Leonetti and Alessandro Zambardi and Ilaria Baffo and Pierluigi Fanelli and Costantino Zazza and Andrea Curatolo and Nicolas Gagliardi and Dario Modenini and Daniele Pecorella and Alice Ponti and Paolo Tortora and Valerio Vagelli and Daniele Brienza and Immacolata Donnarumma and Matteo Mergè and Emanuele Zaccagnino and Alessandro Turchi},
  howpublished = {arXiv},
  year = {2026},
  month = jul,
  doi = {10.48550/arxiv.2607.27460},
  eprint = {2607.27460},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2607.27460},
  note = {CC BY-NC-SA 4.0},
}

TY  - UNPB
TI  - Compton Polarimeter Prototype for the CUbesat Solar Polarimeter (CUSP) mission
AU  - Nicolas De Angelis
AU  - Andrea Alimenti
AU  - Riccardo Campana
AU  - Mauro Centrone
AU  - Giovanni De Cesare
AU  - Ettore Del Monte
AU  - Sergio Di Cosimo
AU  - Enrico Costa
AU  - Sergio Fabiani
AU  - Abhay Kumar
AU  - Pasqualino Loffredo
AU  - Giovanni Lombardi
AU  - Gabriele Minervini
AU  - Fabio Muleri
AU  - Paolo Romano
AU  - Alda Rubini
AU  - Enrico Silva
AU  - Paolo Soffitta
AU  - Giovanni Cucinella
AU  - Vito Di Bari
AU  - Simone Di Filippo
AU  - Andrea Negri
AU  - Massimo Perelli
AU  - Davide Albanesi
AU  - Valerio Campamaggiore
AU  - Giulia de Iulis
AU  - Andrea Del Re
AU  - Paolo Leonetti
AU  - Alessandro Zambardi
AU  - Ilaria Baffo
AU  - Pierluigi Fanelli
AU  - Costantino Zazza
AU  - Andrea Curatolo
AU  - Nicolas Gagliardi
AU  - Dario Modenini
AU  - Daniele Pecorella
AU  - Alice Ponti
AU  - Paolo Tortora
AU  - Valerio Vagelli
AU  - Daniele Brienza
AU  - Immacolata Donnarumma
AU  - Matteo Mergè
AU  - Emanuele Zaccagnino
AU  - Alessandro Turchi
PY  - 2026
DA  - 2026/07/29
PB  - arXiv
DO  - 10.48550/arxiv.2607.27460
UR  - https://arxiv.org/abs/2607.27460
AB  - The space-based CUbesat Solar Polarimeter (CUSP) mission aims to measure the linear polarization of solar flares in the hard X-ray band (25-100 keV) by means of a dual-phase Compton 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 under development as part of the Alcor Program of the Italian Space Agency aimed at developing new CubeSat missions. In the frame of CUSP's Phase B, which started in December 2024, a flight-representative prototype of the Compton polarimeter has been developed and characterized with hard X-ray sources in the laboratory. This prototype consists of a 4×4 central matrix of plastic scintillator bars surrounded by 4 strips of 8 elongated GAGG scintillators, respectively coupled to a multi-anode photomultiplier tube and arrays of avalanche photodiodes. These sensors are read out by custom front-end electronics based on MAROC-3A and SKIROC-2A ASICs with a Xilinx Artix 7 FPGA. The plastic scintillators act as scatterers, while the GAGG bars fully absorb the scattered photons. Coincident plastic-GAGG events allow for reconstructing the Compton scattering direction, whose distribution allows for inferring the polarization parameters of the source. We report here the measured performance of the polarimeter prototype using well-known radioactive isotopes and X-ray tubes, allowing us to assess the performance of our polarimeter prototype over the full 25-100 keV energy range.
ER  -