Millimeter-wave bolometer array receiver for the Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument
Abstract
The Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument is a millimeter-wave cryogenic receiver designed to observe galaxy clusters via the Sunyaev-Zel'dovich effect from the 12 m APEX telescope on the Atacama plateau in Chile. The receiver contains a focal plane of 280 superconducting transition-edge sensor (TES) bolometers instrumented with a frequency-domain multiplexed readout system. The bolometers are cooled to 280 mK via a three-stage helium sorption refrigerator and a mechanical pulse-tube cooler. Three warm mirrors, two 4 K lenses, and a horn array couple the TES bolometers to the telescope. APEX-SZ observes in a single frequency band at 150 GHz with 1' angular resolution and a 22' field-of-view, all well suited for cluster mapping. The APEX-SZ receiver has played a key role in the introduction of several new technologies including TES bolometers, the frequency-domain multiplexed readout, and the use of a pulse-tube cooler with bolometers. As a result of these new technologies, the instrument has a higher instantaneous sensitivity and covers a larger field-of-view than earlier generations of Sunyaev-Zel'dovich instruments. The TES bolometers have a median sensitivity of 890 uKcmb-sqrt(s) (NEy of 3.5e-4 sqrt(s)). We have also demonstrated upgraded detectors with improved sensitivity of 530 uKcmb-sqrt(s) (NEy of 2.2e-4 sqrt(s)). Since its commissioning in April 2007, APEX-SZ has been used to map 48 clusters. We describe the design of the receiver and its performance when installed on the APEX telescope.
Keywords
Cite
@article{arxiv.1008.0342,
title = {Millimeter-wave bolometer array receiver for the Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument},
author = {Daniel Schwan and Peter A. R. Ade and Kaustuv Basu and Amy N. Bender and Frank Bertoldi and Hsaio-Mei Cho and Guyong. Chon and John Clarke and Matt Dobbs and Daniel Ferrusca and Rolfe Gusten and Nils W. Halverson and William L. Holzapfel and Cathy Horellou and Daniel Johansson and Bradley R. Johnson and James Kennedy and Zigmund Kermish and Ruediger Kneissl and Trevor Lanting and Adrian T. Lee and Martin Lueker and Jared Mehl and Karl M. Menten and Dirk Muders and Florian Pacaud and Thomas Plagge and Christian L. Reichardt and Paul L. Richards and Rienhold Schaaf and Peter Schilke and Martin W. Sommer and Helmuth Spieler and Carole Tucker and Axel Weiss and Benjamin Westbrook and Oliver Zahn},
journal= {arXiv preprint arXiv:1008.0342},
year = {2012}
}
Comments
27 pages, 20 figures, prepared with revtex 4.1