Optical Performance of Optical Telescope Assembly of SOT:
Confirmation of Diffraction-Limited Performance
Y. Suematsu, K. Ichimoto, T. Shimizu, M. Otsubo,
M. Nakagiri, M. Noguchi, T. Tamura, Y. Katsukawa,
Y. Kato, H. Hara, M. Miyashita,
S. Tsuneta (NAOJ), M. Kubo, Y. Sakamoto (Univ. of Tokyo),
T. Matsushita, N. Kawaguchi, T. Nakaoji, K. Nagae, S. Shimada
(MELCO), N. Takeyama (GENESIA), and SOT team
Integration and optical test of Optical Telescope Assembly (OTA)
flight model of SOLAR-B Solar Optical Telescope (SOT) has been
completed in a clean room of NAOJ. The main structure of OTA is
an aplanatic Gregorian telescope of a 50 cm effective aperture.
In the optical test simulating a zero-gravity condition, we
confirmed that the OTA has a diffraction-limited performance in
all the range of observable wavelengths (388 - 668 nm), and this
performance does not change after an acoustic and vacuum thermal
cycling test. We also confirmed that thermal deformation of OTA
on-orbit observing condition of the Sun is small, still keeping
the diffraction-limited performance with negligibly small orbital
focus change. We present the method and result of the tests in
detail.
Correspondence
Y. Suematsu (suematsu@solar.mtk.nao.ac.jp), NAOJ
presentation
poster