Cryogenic optical systems for the rapid infrared imager/spectrometer (RIMAS)

Autor: John I. Capone, David A. Content, Alexander S. Kutyrev, Frederick D. Robinson, Gennadiy N. Lotkin, Vicki L. Toy, Sylvain Veilleux, Samuel H. Moseley, Neil A. Gehrels, Stuart N. Vogel
Rok vydání: 2014
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
Popis: The Rapid Infrared Imager/Spectrometer (RIMAS) is designed to perform follow-up observations of transient astronomical sources at near infrared (NIR) wavelengths (0.9 - 2.4 microns). In particular, RIMAS will be used to perform photometric and spectroscopic observations of gamma-ray burst (GRB) afterglows to compliment the Swift satellite’s science goals. Upon completion, RIMAS will be installed on Lowell Observatory’s 4.3 meter Discovery Channel Telescope (DCT) located in Happy Jack, Arizona. The instrument’s optical design includes a collimator lens assembly, a dichroic to divide the wavelength coverage into two optical arms (0.9 - 1.4 microns and 1.4 - 2.4 microns respectively), and a camera lens assembly for each optical arm. Because the wavelength coverage extends out to 2.4 microns, all optical elements are cooled to ~70 K. Filters and transmission gratings are located on wheels prior to each camera allowing the instrument to be quickly configured for photometry or spectroscopy. An athermal optomechanical design is being implemented to prevent lenses from loosing their room temperature alignment as the system is cooled. The thermal expansion of materials used in this design have been measured in the lab. Additionally, RIMAS has a guide camera consisting of four lenses to aid observers in passing light from target sources through spectroscopic slits. Efforts to align these optics are ongoing.
Databáze: OpenAIRE