Invited Presentation

HARP upgrade and its possible replacement

Author(s): Chayanin Larkaew (National Astronomical Research Institute of Thailand)

Presenter: Chayanin Larkaew (National Astronomical Research Institute of Thailand)

C. Larkeaw1, P. Kittara1,2, D. Singwong1, P. Pha-kham1, H. Janthaloet1,3, S. Duangbuppha1, B.-K. Tan5, J.-H. Kim5, P. Janphuang4, M.-J. Wang6, K.-Y. Liu7

1National Astronomical Research Institute of Thailand (Public Organization), Chiang Mai, 50180, Thailand.
2Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
3Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand.
4Synchrotron Light Research Institute, 111 University Avenue, Nakhon Ratchasima, 30000, Thailand.
5Department of Physics (Astrophysics), University of Oxford, Oxford, OX1 3RH, England. 6Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Taipei, 10617, Taiwan. 7East Asian Observatory, University Park, Hilo, HI 96720, USA.

The upgrade of the HARP receiver at the James Clerk Maxwell Telescope (JCMT) has been proposed to enhance its performance by transitioning from single-sideband (SSB) mixers operating over 325–375 GHz to double-sideband (DSB) mixers with a wider RF bandwidth of approximately 211–373 GHz (encompassing Bands 6 and 7), with the longer-term goal of implementing sideband-separating (2SB) mixer blocks featuring improved IF bandwidth.
This upgrade aims to improve receiver sensitivity and expand the capabilities of astronomical observations. To achieve this, the National Astronomical Research Institute of Thailand (NARIT) is collaborating with the University of Oxford to investigate the feasibility of the upgrade using Band 6+7 SIS mixer chips developed at Oxford. NARIT’s supporting infrastructure includes a cryogenic testing system, as well as key instrumentation for the assembly and characterization of SIS mixers. In addition, its machine shop is capable of fabricating key components such as mixer housings and feedhorns.
This talk will introduce the current upgrade concept to the JCMT user community and outline recent progress as well as future replacement plans.