Ref: POSTER-2022-0040

The Pre-flight Calibration of the HRILYA telescope of EUI on-board Solar Orbiter

Schühle, U. ; Teriaca, L. ; Heerlein, K. ; Berghmans, D. ; Auchère, F. ; Gissot, S. ; Kraaikamp, E. ; Harra, L. ; Long, D. ; Stegen, K. ; Verbeeck, C. ; Gottwald, A. ; EUI Team, X.

Poster presented at 8th Solar Orbiter Workhop, Belfast (UK) on 2022-09-12

Abstract: The high-resolution telescope HRILYA of EUI is made for imaging at the Lyman-alpha line of hydrogen. It is constructed of a two-mirror Gregorian telescope with two interference filters at the wavelength of 121.7 nm and a camera using a multichannel plate (MPC) intensifier for high spectral purity around 121.7 nm. Before the launch of Solar Orbiter, together with the two other EUI channels, the HRILYA telescope was calibrated on 20th and 21st April 2017 at the Metrology Light Source (MLS) of PTB in Berlin, where the EUI instrument was placed in a dedicated vacuum tank connected to the MLS beamline. All optical components and the camera had been beforehand calibrated individually by measurements at the MLS on 20th and 21st September 2016. Here we report the results of the component spectral radiometric response calibrations and show how these correspond to the instrument performance before flight. We also provide the gain calibration of the Lyman-alpha camera as function of MCP voltage, which allows comparing results obtained with different MCP voltages. The overall spectral radiometric response of the Lyman-alpha Channel optical system is a result of the combination of the spectral reflectance of the two mirrors, the transmission of the Entrance filter and the narrow-band Focal Plane filter, and the spectral sensitivity of the detector. The spectral behaviour at wavelengths above 160 nm of the responsivity of the Ly-a Channel camera is dominated by the intensifier and the KBr coating of the MCP. There are two on-board UV-LEDs that can be used individually for illumination of the detector at a wavelength of 245 nm. The UV-LEDs can be used for tracking of the Lyman- alpha camera response alone at any time of the mission and so, checking its state of health.

Keyword(s): Sun ; corona ; EUI
Note: Poster P136 in the conference abstract book

The record appears in these collections:
Royal Observatory of Belgium > Solar Physics & Space Weather (SIDC)
Conference Contributions & Seminars > Posters
Solar-Terrestrial Centre of Excellence

 Record created 2022-10-21, last modified 2022-10-21