The IXPE instrument calibration equipment
Fabio Muleri, Raffaele Piazzolla, Alessandro Di Marco, Sergio Fabiani, Fabio La Monaca, Carlo Lefevre, Alfredo Morbidini, John Rankin, P. Soffitta, Antonino Tobia, Fei Xie, Fabrizio Amici, Primo Attinà, Matteo Bachetti, Daniele Brienza, Mauro Centrone, E. Costa, E. Del Monte, Sergio Di Cosimo, Giuseppe Di Persio, Y. Evangelista, Riccardo Ferrazzoli, Pasqualino Loffredo, M. Perri, M. Pilia, Simonetta Puccetti, Ajay Ratheesh, A. Rubini, Francesco Santoli, Emanuele Scalise, A. Trois
Abstract
The Imaging X-ray Polarimetry Explorer is a mission dedicated to the measurement of X-ray polarization from tens of astrophysical sources belonging to different classes. Expected to be launched at the end of 2021, the payload comprises three mirrors and three focal plane imaging polarimeters, the latter being designed and built in Italy. While calibration is always an essential phase in the development of high-energy space missions, for IXPE it has been particularly extensive both to calibrate the response to polarization, which is peculiar to IXPE, and to achieve a statistical uncertainty below the expected sensitivity. In this paper we present the calibration equipment that was designed and built at INAF-IAPS in Rome, Italy, for the calibration of the polarization-sensitive focal plane detectors on-board IXPE. Equipment includes calibration sources, both polarized and unpolarized, stages to align and move the beam, test detectors and their mechanical assembly. While all these equipments were designed to fit the specific needs of the IXPE Instrument calibration, their versatility could also be used in the future for other projects.