Wide field CMB polarization telescope with cryogenic Si lenses

2021 Fiscal Year Final Research Report

• Project/Area Number: 17H01115
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Astronomy
• Research Institution: Japan Aerospace EXploration Agency
• Principal Investigator: Sekimoto Yutaro 国立研究開発法人宇宙航空研究開発機構, 宇宙科学研究所, 教授 (70262152)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 宇宙マイクロ波背景放射 / ミリ波光学系 / 広視野偏光観測 / 極低温望遠鏡 / 反射防止加工

Outline of Final Research Achievements

Cosmic microwave background (CMB) polarization observations can trace primordial gravitational waves with B-mode polarization pattern caused by cosmic inflation. We have developed a wide-field millimeter-wave telescope suitable for CMB polarization observation. By observing broadband and wide field of CMB, it is possible to efficiently separate the foreground radiation from interstellar dust in the galactic plane. We have developed a broadband anti-reflection structure on a silicon (Si) lens which has a high refractive index and low loss. We have also succeeded a precise near-field beam pattern measurement of a wide-field telescope including a cross-polarization pattern.

Free Research Field

宇宙物理学実験

Academic Significance and Societal Importance of the Research Achievements

本研究では広視野CMB偏光望遠鏡やその広角サイドローブの測定が実現した。これらは今後のCMB偏光実験や広視野ミリ波望遠鏡にも応用可能となる。高い屈折率かつ低損失のシリコンは、ミリ波光学系としてとても有望である。本研究による広帯域反射防止構造による大型のシリコンレンズは今後様々な分野で利用が可能となる。広視野CMB偏光望遠鏡の開発やその評価手法は、ミリ波天文学や大容量通信分野への発展につながる。