Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Optical design for the 450, 350, and 200 µm ArTeMiS camera

Dubreuil, Didier, Martignac, Jerome, Toussaint, Jean Christian, Visticot, Francois, Delisle, Cyrille, Gallais, Pascal, Le-Pennec, Jean, Lerch, Thierry, Andre, Philippe, Lortholary, Michel, Maffei, Bruno, Haynes, Vic, Hurtado, Norma, Pisano, Giampaolo, Reveret, Vincent, Rodriguez, Louis and Talvard, Michel 2014. Optical design for the 450, 350, and 200 µm ArTeMiS camera. Presented at: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII, Montreal, Quebec, Canada, 24- 27 June 2014. Published in: Holland, Wayne S. and Zmuidzinas, Jonas eds. Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. SPIE Proceedings , vol. 9153. Bellingham, WA: International Society for Optical Engineering, 10.1117/12.2055531

Full text not available from this repository.

Abstract

ArTeMiS is a submillimeter camera planned to work simultaneously at 450 mum, 350 mum and 200 mum by use of 3 focal planes of, respectively, 8, 8 and 4 bolometric arrays, each one made of 16 x18 pixels. In July 2013, with a preliminary setting reduced to 4 modules and to the 350 mum band, ArTeMiS was installed successfully at the Cassegrain focus of APEX, a 12 m antenna located on the Chajnantor plateau, Chile. After the summary of the scientific requirements, we describe the main lines of the ArTeMiS nominal optical design with its rationale and performances. This optical design is highly constrained by the room allocation available in the Cassegrain cabin. It is an all-reflective design including a retractable pick off mirror, a warm Fore Optics to image the focal plane of the telescope inside the cryostat, and the cold optics. The large size of the field of view at the focal plane of the telescope, 72 mm x 134 mm for the 350 mum and 450 mum beams, leads to the use of biconical toroidal mirrors. In this way, the nominal image quality obtained on the bolometric arrays is only just diffraction limited at some corners of the field of view. To keep a final PSF as much uniform as possible across the field of view, we have used the technic of manufacturing by diamond turning to machine the mirrors. This approach, while providing high accuracy on the shape of the mirrors, made easier the control of the two sub units, the Fore Optics and the cold optics, in the visible domain and at room temperature. Moreover, the use of the similar material (Aluminium alloy 6061) for the optical bench and the mirrors with their mount ensures a homothetic shrinking during the cooling down. The alignment protocol, drew up at the early step of the study, is also presented. It required the implementation of two additional mechanisms inside the cryostat to check the optical axis of the cold optics, in the real conditions of operation of ArTeMiS. In this way, it was possible to pre-align the Fore Optics sub unit with respect to the cold optics. Finally, despite the high constraints of the operating conditions of APEX, this protocol allowed to align ArTeMiS with respect to the telescope in a single adjustment. The first images obtained on the sky, Saturn with its rings, are given

Item Type: Conference or Workshop Item (Paper)
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Subjects: Q Science > Q Science (General)
Q Science > QB Astronomy
Publisher: International Society for Optical Engineering
ISBN: 9780819496218
ISSN: 0277-786X
Last Modified: 04 Jun 2017 09:22
URI: http://orca.cf.ac.uk/id/eprint/94239

Citation Data

Cited 1 time in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item