KAGRA is a laser interferometric gravitational wave (GW) telescope in Japan. It joined O4, the fourth international GW observation run, with other telescopes, namely, Laser Interferometer Gravitational Wave Observatory (LIGO) and Virgo. In the previous GW observation runs: O1, O2, and O3, 90 events were reported, and many more events are expected to be observed in O4. With the beginning of GW astronomy, the calibration of observed GW signals is becoming more important than ever before. The main calibration system used in KAGRA, LIGO, and Virgo is a photon calibration system (Pcal), which injects reference signals into a telescope by the radiation pressure of a laser. On the basis of the preparation and operation of KAGRA Pcals in O3, we prepared an upgrading plan for O4. This plan includes three main improvements: improving the Pcal laser beam alignment system, reducing noise, and dereasing uncertainty. Improvement works were conducted between the end of O3 and the start of O4 in accordance with this plan. The following results were obtained: first, precise remote alignment was enabled in the critical Pcal laser path region. Second, a Pcal noise source was identified and noise was significantly improved, resulting in a remarkable 50 dB reduction and sufficient reduction of the Pcal noise below the design sensitivity of KAGRA. Third, studies on the temperature dependence and laser incidence state dependence of the integrating sphere-type power meter were conducted to reduce the uncertainty of the Pcal, which is directly related to the uncertainty of the telescope signal. The details of the KAGRA Pcal and the improvements made between O3 and O4 are reported in this study.
Calibration of the gravitational wave telescope KAGRA / Chen, D.; Abe, H.; Akutsu, T.; Ando, M.; Aoumi, M.; Araya, A.; Aritomi, N.; Aso, Y.; Bae, S.; Bajpai, R.; Cannon, K.; Cao, Z.; Chang, R. -J.; Chen, A. H. -Y.; Chen, D.; Chen, H.; Chen, Y.; Chiba, A.; Chiba, R.; Chou, C.; Eisenmann, M.; Fujii, S.; Fukunaga, I.; Haba, D.; Haino, S.; Han, W. -B.; Hayakawa, H.; Hayama, K.; Himemoto, Y.; Hirata, N.; Hirose, C.; Hoshino, S.; Hsieh, H. -F.; Hsiung, C.; Hsu, S. -C.; Hui, D. C. Y.; Inayoshi, K.; Itoh, Y.; Iwaya, M.; Jin, H. B.; Jung, K.; Kajita, T.; Kamiizumi, M.; Kanda, N.; Kato, J.; Kato, T.; Kim, S.; Kimura, N.; Kiyota, T.; Kohri, K.; Kokeyama, K.; Komori, K.; Kong, A. K. H.; Koyama, N.; Kume, J.; Kuroyanagi, S.; Kuwahara, S.; Kwak, K.; Lai, S.; Lee, H. W.; Lee, R.; Lee, S.; Leonardi, M.; Li, K. L.; Lin, L. C. -C.; Lin, C. -Y.; Lin, E. T.; Liu, G. C.; Ma, L. -T.; Maeda, K.; Matsuyama, M.; Meyer-Conde, M.; Michimura, Y.; Mio, N.; Miyakawa, O.; Miyamoto, S.; Miyoki, S.; Morisaki, S.; Moriwaki, Y.; Murakoshi, M.; Nakamura, K.; Nakano, H.; Narikawa, T.; Nguyen Quynh, L.; Nishino, Y.; Nishizawa, A.; Obayashi, K.; Oh, J. J.; Oh, K.; Ohashi, M.; Ohkawa, M.; Oohara, K.; Oshima, Y.; Oshino, S.; Page, M. A.; Pan, K. -C.; Park, J.; Pena Arellano, F. E.; Saha, S.; Sakai, K.; Sako, T.; Sato, R.; Sato, S.; Sato, Y.; Sawada, T.; Sekiguchi, Y.; Shao, L.; Shikano, Y.; Shimode, K.; Shinkai, H.; Shiota, J.; Somiya, K.; Suzuki, T.; Suzuki, T.; Tagoshi, H.; Takahashi, H.; Takahashi, R.; Takamori, A.; Takatani, K.; Takeda, H.; Takeda, M.; Tamaki, M.; Tanaka, K.; Tanaka, S. J.; Tanaka, T.; Taruya, A.; Tomaru, T.; Tomita, K.; Tomura, T.; Toriyama, A.; Trani, A. A.; Tsuchida, S.; Uchikata, N.; Uchiyama, T.; Uehara, T.; Ueno, K.; Ushiba, T.; van Putten, M. H. P. M.; Wang, H.; Washimi, T.; Wu, C.; Wu, H.; Yamamoto, K.; Yamamoto, M.; Yamamoto, T.; Yamamoto, T. S.; Yamamura, S.; Yamazaki, R.; Yang, L. -C.; Yang, Y.; Yeh, S. -W.; Yokoyama, J.; Yokozawa, T.; Yuzurihara, H.; Zhao, Y.; Zhu, Z. -H.. - In: POS PROCEEDINGS OF SCIENCE. - ISSN 1824-8039. - 444:(2024).
Calibration of the gravitational wave telescope KAGRA
Leonardi M.;Yamamoto K.;
2024-01-01
Abstract
KAGRA is a laser interferometric gravitational wave (GW) telescope in Japan. It joined O4, the fourth international GW observation run, with other telescopes, namely, Laser Interferometer Gravitational Wave Observatory (LIGO) and Virgo. In the previous GW observation runs: O1, O2, and O3, 90 events were reported, and many more events are expected to be observed in O4. With the beginning of GW astronomy, the calibration of observed GW signals is becoming more important than ever before. The main calibration system used in KAGRA, LIGO, and Virgo is a photon calibration system (Pcal), which injects reference signals into a telescope by the radiation pressure of a laser. On the basis of the preparation and operation of KAGRA Pcals in O3, we prepared an upgrading plan for O4. This plan includes three main improvements: improving the Pcal laser beam alignment system, reducing noise, and dereasing uncertainty. Improvement works were conducted between the end of O3 and the start of O4 in accordance with this plan. The following results were obtained: first, precise remote alignment was enabled in the critical Pcal laser path region. Second, a Pcal noise source was identified and noise was significantly improved, resulting in a remarkable 50 dB reduction and sufficient reduction of the Pcal noise below the design sensitivity of KAGRA. Third, studies on the temperature dependence and laser incidence state dependence of the integrating sphere-type power meter were conducted to reduce the uncertainty of the Pcal, which is directly related to the uncertainty of the telescope signal. The details of the KAGRA Pcal and the improvements made between O3 and O4 are reported in this study.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione
