Detalles de publicación

PP 026031

Optimization procedure of the baffle of the GroundBIRD Telescope to mitigate stray light

M. Tsujii (1), T. Tanaka (1), A. Fasano (2,3), R. Génova-Santos (2,3), S. Honda (4), Y. Jo (5), K. Kataoka (6), C. Otani (7), M. Peel (8), J. Suzuki (6), O. Tajima (6), E. Won (5), and M. Hattori (1)
(1) Tohoku University, (2) IAC, (3) ULL, (4) Tsukuba University, (5) Korea University, (6) Kyoto University, (7) RIKEN, (8) Imperial College London
We present the optimization procedure of the baffle mounted on the GroundBIRD telescope for measuring the
polarization of the Cosmic Microwave Background (CMB). The telescope employs a dual mirror reflective telescope installed in a cryostat. The primary objectives were to minimize stray light contamination, maintain the integrity of the main beam, and ensure that thermal loading from the baffle remains significantly below that from the atmosphere. Using quasi-optical simulations, we have optimized the baffle’s aperture angle to suppress stray light without degrading the main beam quality. We confirmed
through Moon observations that the optimized baffle design works to eliminate the contamination of the stray light as expected. Furthermore, no measurable degradation in the noise equivalent temperature (NET) was detected, indicating minimal thermal impact. These results show that our baffle optimization
strategy effectively reduces systematic errors while maintaining observational sensitivity, providing valuable insights for future CMB experiments with similar optical architectures.

 
Aceptado para publicación en IEEE | Enviado el 2026-03-09 | Proyecto P/302122