Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for SUNRISE III: polarization modulation unit

Masahito Kubo; Toshifumi Shimizu; Yukio Katsukawa; Yusuke Kawabata; Tetsu Anan; Kiyoshi Ichimoto; Kazuya Shinoda; Tomonori Tamura; Yoshifumi Nodomi; Satoshi Nakayama; Takuya Yamada; Takao Tajima; Shimpei Nakata; Yoshihito Nakajima; Kousei Okutani; Alex Feller; Jose Carlos del Toro Iniesta

doi:10.1117/12.2560457

13 December 2020 Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for SUNRISE III: polarization modulation unit

Masahito Kubo, Toshifumi Shimizu, Yukio Katsukawa, Yusuke Kawabata, Tetsu Anan, Kiyoshi Ichimoto, Kazuya Shinoda, Tomonori Tamura, Yoshifumi Nodomi, Satoshi Nakayama, Takuya Yamada, Takao Tajima, Shimpei Nakata, Yoshihito Nakajima, Kousei Okutani, Alex Feller, Jose Carlos del Toro Iniesta

Author Affiliations +

Proceedings Volume 11447, Ground-based and Airborne Instrumentation for Astronomy VIII; 11447A3 (2020) https://doi.org/10.1117/12.2560457
Event: SPIE Astronomical Telescopes + Instrumentation, 2020, Online Only

Conference Poster

Abstract

Polarization measurements of the solar chromospheric lines at high precision are key to present and future solar telescopes for understanding magnetic field structures in the chromosphere. The Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for Sunrise III is a spectropolarimeter with a polarimetric precision of 0.03 % (1 σ). The key to high-precision polarization measurements using SCIP is a polarization modulation unit that rotates a waveplate continuously at a constant speed. The rotating mechanism is a DC brushless motor originally developed for a future space mission, and its control logic was originally developed for the sounding rocket experiment CLASP. Because of our requirement on a speed of rotation (0.512 s/rotation) that was 10 times faster than that of CLASP, we optimized the control logic for the required faster rotation. Fast polarization modulation is essential for investigating the fine-scale magnetic field structures related to the dynamical chromospheric phenomena. We have verified that the rotation performance can achieve the polarization precision of 0.03 % (1 σ) required by SCIP and such a significant rotation performance is maintained under thermal vacuum conditions by simulating the environment of the Sunrise III balloon flight. The waveplate was designed as a pair of two birefringent plates made of quartz and sapphire to achieve a constant retardation in a wide wavelength range. We have confirmed that the retardation is almost constant in the 770 nm and 850nm wavelength bands of SCIP under the operational temperature conditions.

Citation Download Citation

Masahito Kubo, Toshifumi Shimizu, Yukio Katsukawa, Yusuke Kawabata, Tetsu Anan, Kiyoshi Ichimoto, Kazuya Shinoda, Tomonori Tamura, Yoshifumi Nodomi, Satoshi Nakayama, Takuya Yamada, Takao Tajima, Shimpei Nakata, Yoshihito Nakajima, Kousei Okutani, Alex Feller, and Jose Carlos del Toro Iniesta "Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for SUNRISE III: polarization modulation unit", Proc. SPIE 11447, Ground-based and Airborne Instrumentation for Astronomy VIII, 11447A3 (13 December 2020); https://doi.org/10.1117/12.2560457

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available