TY - GEN
T1 - The Thermal Filter for the Solar Ultraviolet Imaging Telescope (SUIT) on-board Aditya-L1
AU - Ghosh, Avyarthana
AU - Kesharwani, Ravi
AU - Khan, Aafaque R.
AU - Padinhatteeri, Sreejith
AU - Tripathi, Durgesh
AU - Ramaprakash, A. N.
AU - Patel, Ketan
AU - Jalluri, Tayaramma D.P.V.
AU - Madhumalathi, G. R.
AU - Venkateshwaran, R.
AU - Elumalai, S.
AU - Gupta, Kingshuk
AU - Nair, J. P.
AU - Sparrow, H.
AU - Worlikar, R. S.
AU - Gupta, Anit
AU - Sen, Sanjoy
N1 - Publisher Copyright:
© 2022 SPIE. All rights reserved.
PY - 2022
Y1 - 2022
N2 - The Solar Ultraviolet Imaging Telescope (SUIT) is an imaging telescope on-board the Aditya-L1 satellite, which is India’s maiden space mission dedicated solely to solar observations. The spatially resolved, high cadence observations are designed to be taken in eleven science filters with Full Width Half Maxima ranging between 0.1–58 nm and spread over the Near-Ultraviolet (NUV) domain of the solar spectrum (200–400 nm). The huge incoming solar flux, limited by the linearity regime performance of the Charge Coupled Device (CCD) as well as the thermal operational constraints, mandate the use of an entrance aperture filter, the Thermal Filter (TF), for SUIT. The design of this filter is, further, constrained by exposure time and enhanced emission of the Sun during eruptive events. From performance perspective, the TF reflects ∼50% of the incident radiation and allows only 0.1–0.45% of the incoming flux to pass within 200–400 nm. The transmission on either side of the operational range is satisfactorily reduced, so as to ensure minimum unwanted light leaking into the imaging system. Therefore, the TF plays a significant role in increasing the photometric efficiency as well as maintaining the operational temperature of the telescope. To the best of our knowledge, this is the first time any attempt of designing and manufacturing any such rejection filter aiming optimized performance in the NUV range is being done for a space-based imaging solar telescope. The choice of materials for substrate and coating for the filter poses several challenges in terms of contamination, corrosion/ oxidation, durability during manufacturing process, long-term exposure to harsh space environment as well as formation of pinholes. The transmission and reflection profiles of the fabricated TF is satisfactory to meet our design and technical constraints. The TF is also qualified for various environmental and radiation conditions. The transmission of the TF is seen to be well within our allowed margins (±10% of the design value) even after being exposed to these qualification tests.
AB - The Solar Ultraviolet Imaging Telescope (SUIT) is an imaging telescope on-board the Aditya-L1 satellite, which is India’s maiden space mission dedicated solely to solar observations. The spatially resolved, high cadence observations are designed to be taken in eleven science filters with Full Width Half Maxima ranging between 0.1–58 nm and spread over the Near-Ultraviolet (NUV) domain of the solar spectrum (200–400 nm). The huge incoming solar flux, limited by the linearity regime performance of the Charge Coupled Device (CCD) as well as the thermal operational constraints, mandate the use of an entrance aperture filter, the Thermal Filter (TF), for SUIT. The design of this filter is, further, constrained by exposure time and enhanced emission of the Sun during eruptive events. From performance perspective, the TF reflects ∼50% of the incident radiation and allows only 0.1–0.45% of the incoming flux to pass within 200–400 nm. The transmission on either side of the operational range is satisfactorily reduced, so as to ensure minimum unwanted light leaking into the imaging system. Therefore, the TF plays a significant role in increasing the photometric efficiency as well as maintaining the operational temperature of the telescope. To the best of our knowledge, this is the first time any attempt of designing and manufacturing any such rejection filter aiming optimized performance in the NUV range is being done for a space-based imaging solar telescope. The choice of materials for substrate and coating for the filter poses several challenges in terms of contamination, corrosion/ oxidation, durability during manufacturing process, long-term exposure to harsh space environment as well as formation of pinholes. The transmission and reflection profiles of the fabricated TF is satisfactory to meet our design and technical constraints. The TF is also qualified for various environmental and radiation conditions. The transmission of the TF is seen to be well within our allowed margins (±10% of the design value) even after being exposed to these qualification tests.
UR - https://www.scopus.com/pages/publications/85140484337
UR - https://www.scopus.com/pages/publications/85140484337#tab=citedBy
U2 - 10.1117/12.2629760
DO - 10.1117/12.2629760
M3 - Conference contribution
AN - SCOPUS:85140484337
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Space Telescopes and Instrumentation 2022
A2 - den Herder, Jan-Willem A.
A2 - Nikzad, Shouleh
A2 - Nakazawa, Kazuhiro
PB - SPIE
T2 - Space Telescopes and Instrumentation 2022: Ultraviolet to Gamma Ray
Y2 - 17 July 2022 through 22 July 2022
ER -