000007723 001__ 7723
000007723 005__ 20260105211347.0
000007723 037__ $$aSCART-2026-0013
000007723 100__ $$aGissot, S.
000007723 245__ $$aInitial radiometric calibration of the HRIEUV telescope of the EUI instrument on board Solar Orbiter
000007723 260__ $$c2025
000007723 520__ $$aContext. The HRIEUV telescope was calibrated on ground at the Physikalisch-Technische Bundesanstalt (PTB), Germany’s national metrology institute, using the Metrology Light Source (MLS) synchrotron in April 2017 during the calibration campaign of the Extreme Ultraviolet Imager (EUI) instrument on board the Solar Orbiter mission. Aims. We used the pre-flight end-to-end calibration and component-level (mirror multilayer coatings, filters, detector) characterization results to establish the beginning-of-life performance of the HRIEUV telescope, which will serve as a reference for radiometric analysis and monitoring of the telescope in-flight degradation. Methods. Calibration activities at component level and end-to-end calibration of the instrument were performed at PTB/MLS synchrotron light source (Berlin, Germany) and the SOLEIL synchrotron (Orsay, France). Each component optical property is measured and compared to its semi-empirical model. This pre-flight characterization is used to estimate the parameters of the semi-empirical models. The end-to-end response is measured and validated by comparison with calibration measurements, as well as with its main design performance requirements. Results. The telescope spectral response semi-empirical model is validated by the pre-flight end-to-end ground calibration of the instrument. It is found that HRIEUV is a highly efficient solar EUV telescope with a peak efficiency superior to 1 e−.ph−1, low detector noise (≈2.8 e rms), low dark current at operating temperature, and a pixel saturation above 120 ke- in low-gain or combined image mode. The ground calibration also confirms a well-modelled spectral selectivity and rejection, and low stray light. The EUI instrument achieves a state-of-the-art performance in terms of signal-to-noise and spatial resolution.
000007723 594__ $$aSTCE
000007723 6531_ $$aSolar Orbiter
000007723 6531_ $$aEUI
000007723 6531_ $$acalibration
000007723 700__ $$aAuchère, F.
000007723 700__ $$aBerghmans, D.
000007723 700__ $$aGiordanengo, B.
000007723 700__ $$aBenMoussa, A.
000007723 700__ $$aRebellato, J.
000007723 700__ $$aHarra, L.
000007723 700__ $$aLong, D.
000007723 700__ $$aRochus, P.
000007723 700__ $$aSchühle, U.
000007723 700__ $$aAznar Cuadrado, R.
000007723 700__ $$aDelmotte, F.
000007723 700__ $$aDumesnil, C.
000007723 700__ $$aGottwald, A.
000007723 700__ $$aHalain, J. -P.
000007723 700__ $$aHeerlein, K.
000007723 700__ $$aHellin, M. -L.
000007723 700__ $$aHermans, A.
000007723 700__ $$aJacques, L.
000007723 700__ $$aKraaikamp, E.
000007723 700__ $$aMercier, R.
000007723 700__ $$aRochus, P.
000007723 700__ $$aSmith, P. J.
000007723 700__ $$aTeriaca, L.
000007723 700__ $$aVerbeeck, C.
000007723 700__ $$aDickson, E. C. M.
000007723 773__ $$pAstronomy and Astrophysics$$y2025
000007723 8560_ $$fdavid.berghmans@ksb-orb.be
000007723 85642 $$ahttps://arxiv.org/abs/2307.14182
000007723 905__ $$ain press to
000007723 980__ $$aREFERD