An extremely high stability cooling system for planet hunter

Cryogenic Engineering Conference 2017

材料科学;物理学

Lizon, Allemand L.^1 ; Becerril, S.^2 ; Mirabet, E.^2

ESO, Karl-Schwarzschild-Strasse 2, Garching bei München

85748, Germany^1

Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia s/n, Granada

E-18008, Spain^2

关键词: Almeria , Spain;    Core systems;    Operating temperature;    Optomechanical;    Periodical variation;    Radial velocity;    Spectral line;    State of the art;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012190/pdf
DOI  :  10.1088/1757-899X/278/1/012190

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The detection of exoplanets is done by measuring very tiny periodical variations of the radial velocity of the parent star. Extremely stable spectrographs are required in order to enhance the wavelength variations of the spectral lines due to Doppler effect. CARMENES is the new high-resolution, high-stability spectrograph built for the 3.5 m telescope at the Calar Alto Observatory (CAHA, Almeria, Spain) by a consortium formed by German and Spanish institutions. This instrument is composed of two separated spectrographs: VIS channel (550-1050 nm) and NIR channel (950-1700 nm). The NIR-channel spectrograph's has been built under the responsibility of the Instituto de Astrofisica de Andalucia (IAA-CSIC). It has been manufactured, assembled, integrated and verified in the last two years, delivered in fall 2015 and commissioned in December 2015. Beside the various opto-mechanical challenges, the cooling system was one of the most demanding sub-systems of the NIR channel. Due to the highly demanding requirements applicable in terms of stability, this system arises as one of the core systems to provide outstanding stability to the channel at an operating temperature finally fixed at 140 K. Really at the edge of the state-of-the-art, the Cooling System is able to provide to the cold mass (∼1 Ton) better thermal stability than few hundredths of a degree over 24 hours (goal: 0.01K/day). The present paper describes the main technical approach, which has been taken in order to reach this very ambitious performance.