CARMENES ultra-stable cooling system: Very promising results

DOI: 
10.1117/12.2055570
Publication date: 
01/07/2014
Main author: 
Mirabet E.
IAA authors: 
Mirabet, E.;Becerril, S.;Rodríguez, E.;Abril, M.;Cárdenas, M.C.;Morales, R.;Pérez, D.;Sánchez Carrasco, M.A.;Amado, P.J.
Authors: 
Mirabet E., Carvas P., Lizon J.-L., Becerril S., Rodríguez E., Abril M., Cárdenas M.C., Morales R., Pérez D., Sánchez Carrasco M.A., Amado P.J., Seifert W., Quirrenbach A., Caballero J.A., Ribas I., Reiners A., Dreizler S.
Journal: 
Proceedings of SPIE - The International Society for Optical Engineering
Publication type: 
Article
Volume: 
9151
Pages: 
Number: 
91513Y
Abstract: 
CARMENES is a high resolution spectrograph to detect planets through the variation of radial velocity, destined for the Calar Alto Observatory in Almeria, Spain. The optical bench has a working temperature of 140K with a 24 hours stability of ±0,1K; goal ±0,01K. It is enclosed with a radiation shield actively cooled with thermalized nitrogen gas that flows through strategically positioned heat exchangers to remove its radiative load. The cooling system has an external preparation unit (N2GPU), which provides the nitrogen gas through actively vaporizing liquid nitrogen with heating resistances and a three stage circuit flow, each one controlled by an independent PID. Since CARMENES is still in the construction phase, a dedicated test facility has been built in order to simulate the instrument and correctly establish the N2GPU parameters. Furthermore, the test facility allows a wide range of configurations set-ups, which enables a full characterization of the N2GPU and the cooling system. The N2GPU has been designed to offer a wide temperature range of thermally stabilized nitrogen gas flow, which apart from CARMENES could also be used to provide ultra-high thermal stability in other cryogenic instruments. The present paper shows the testing of the cooling performance, the hardware used and the very promising results obtained. © 2014 SPIE.
Database: 
SCOPUS
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2014SPIE.9151E..3YM/abstract
ADS Bibcode: 
2014SPIE.9151E..3YM
Keywords: 
Cooling; Cryogenics; Extrasolar planets; Large instrument; Near-infrared instrumentation; Nitrogen circulation; Thermal stability