Aug 4 Wed 15:00～16:00 ALMA-J seminar zoom
Aug 4 Wed 15:30～17:00 NAOJ Science Colloquium zoom
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8月4日（水）
Campus: Mitaka
Seminar: ALMA-J seminar
Regularly Scheduled/Sporadic: Every Wednesday Date and Time: 2021 August 4 15:00-16:00
Place: Zoom
Speaker：Takaho Masai (SOKENDAI/NAOJ)
Title: Investigation on Aperture Efficiency Degradation Due to Aberrations in (Sub)mm-wave Telescopes Towards high-Performance Multibeam Heterodyne-Receiver Optics Designs
Abstract: Multibeam heterodyne receivers and their application to wide-field observations in radio telescopes have been identified as one mid-term upgrade opportunity for ALMA towards the 2030s. With the development of state-of-the-art microwave components, we require careful consideration of the receiver optics for the implementation of a multibeam receiver in ALMA. Traditionally, Geometrical optics and ray tracing methods were used to design multibeam receiver optics. Additionally, multibeam receivers will have the receiver pixels spread out on the focal plane. The receiver pixels offset from the telescope focus will suffer from aberrations resulting in a loss of aperture efficiency. The connection between the traditional optical methods and aberrations to aperture efficiency is the key to determine design goals and performance requirements towards high-performance multibeam receiver optics. In this talk, I will introduce the traditional optical methods along with a quantitative relation to aperture efficiency. Additionally, I will show simulation results of the effect of aberrations in multibeam receivers.
Facilitator: Yoshito Shimajiri , Shun Ishii
8月4日（水）
Campus：Mitaka
Seminar：NAOJ Science Colloquium
Regularly Scheduled/Sporadic：Every Wednesday
Date and time：2021 August 4, 15:30-17:00
Place：zoom
Speaker：Malgorzata Bogdan
Affiliation：Lund university
Title：TBD
Abstract：TBD
Facilitator
-Name：Akimasa Kataoka
Comment：English