Design of the near infrared camera DIRAC for East Anatolia Observatory
Özet
The 4m DAG telescope is under construction at East Anatolia Observatory in Turkey. DIRAC, the " DAG InfraRed Adaptive optics Camera", is one of the facility instruments. This paper describes the design of the camera to meet the performance specifications. Adaptive and auxiliary optics relay the telescope F/14 input 1:1 into DIRAC. The camera has an all refractive design for the wavelength range 0.9 - 2.4 micron. Lenses reimage the telescope focal plane 33 x 33 as (9 x 9 mm) on a 1k x 1k focal plane array. With magnification of 2x, the plate scale on the detector is 33 mas/pixel. There are 4 standard filters (Y, J, H, K) and 4 narrowband continuum filters. A 12 position filter wheel allows installation of 2 extra customer filters for specific needs; the filter wheel also deploys a pupil viewer lens. Optical tolerancing is carried out to deliver the required image quality at polychromatic Strehl ratio of 90% with focus compensator. This reveals some challenges in the precision assembly of optics for cryogenic environments. We require cells capable of maintaining precision alignment and keeping lenses stress free. The goal is achieved by a combination of flexures with special bonding epoxy matching closely the CTE of the lens cells and crystalline materials. The camera design is very compact with object to image distance <220 mm and lens diameters <25 mm. A standalone cryostat is LN2 cooled for vibration free operation with the bench mounted adaptive optics module (TROIA) and coronagraph (PLACID) at the Nasmyth focus of the DAG telescope.
Anahtar kelimeler
Atıf için künye
Zhelem, R., Content, R., Churilov, V., Kripak, Y., Waller, L., Case, S., Mali, S., Muller, R., Gonzalez, M., Adams, D., Binos, N., Chin, T., Farrell, T., Klauser, U., Kondrat, Y., Kunwar, N., Lawrence, J., Lorente, N., Luo, S., … Jolissaint, L. (2022). Design of the near infrared camera DIRAC for East Anatolia Observatory. Conference on Ground-Based and Airborne Instrumentation for Astronomy IX, Montreal. https://doi.org/10.1117/12.2629716
BibTeX
@inproceedings{zhelem2022-61840,
author = {Zhelem, Ross and Content, Robert and Churilov, Vladimir and Kripak, Yevgen and Waller, Lew and Case, Scott and Mali, Slavko and Muller, Rolf and Gonzalez, Mario and Adams, Dave and Binos, Nick and Chin, Timothy and Farrell, Tony and Klauser, Urs and Kondrat, Yuriy and Kunwar, Nirmala and Lawrence, Jon and Lorente, Nuria and Luo, Summer and McDonald, Erica and McGregor, Helen and Nichani, Vijay and Pai, Naveen and Vuong, Minh and Zahoor, Jahanzeb and Zheng, Jessica and Norris, Barnaby and Bryant, Julia and Vaccarella, Annino and Herrald, Nick and Gilbert, James and Yeşilyaprak, Cahit and Gucsav, Bulent and Coker, Deniz and Keskin, Onur and Jolissaint, Laurent},
title = {Design of the near infrared camera DIRAC for East Anatolia Observatory},
booktitle = {Conference on Ground-Based and Airborne Instrumentation for Astronomy IX},
address = {Montreal},
year = {2022},
doi = {10.1117/12.2629716},
url = {https://akademik.atauni.edu.tr/yayinlar/61840-design-of-the-near-infrared-camera-dirac-for-east-anatolia-observatory}
}