| Presenter: | Yoichiro Hanaoka |
| Affiliation: | National Astronomical Observatory of Japan |
| Title: | Calibration of the polarimeters with ferroelectric liquid crystals |
| Authors: | Y. Hanaoka |
| Form: | poster |
| Abstract: | The solar group of the National Astronomical Observatory of Japan is operating two polarimeters using Ferroelectric Liquid Crystals (FLCs) for regular solar observations in the Fe 6303 and the H$\alpha$ lines, and they realized the polarimetry with very high sensitivity. Furthermore, we are now constructing a couple of more FLC polarimeters. Thus we are trying to establish a standard design and a standard calibration procedure for the FLC polarimeters, which enables us to install the polarimeter to various telescopes easily. Since the FLCs are not very stable devices, it is important that we can obtain the calibration data at any time with any telescope. We picked up the various characteristics of the FLC polarimeters which are required for the calibration for the high-sensitivity polarimetry, and investigated their time variation for more than one year. We will present the results and discuss the procedure to keep the high reliability of the polarization measurements considering the variation of the parameters. |
| Session: | 6. Coronal radio and infrared polarimetry |
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