Unintended consequences on vacuum hold time with conversion to PolyCold closed-cycle coolers

Tom Benedict; Gregory A. Barrick

doi:10.1117/12.926428

13 September 2012 Unintended consequences on vacuum hold time with conversion to PolyCold closed-cycle coolers

Tom Benedict, Gregory A. Barrick

Proceedings Volume 8450, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II; 84504M (2012) https://doi.org/10.1117/12.926428
Event: SPIE Astronomical Telescopes + Instrumentation, 2012, Amsterdam, Netherlands

Abstract

In 2009, the Canada-France-Hawaii Telescope converted the dewar for the ESPaDOnS spectrograph from using liquid nitrogen cooling to using a Polycold^® closed-cycle cooler. It was found that the higher temperature of the closed-cycle cooler degraded the efficiency of the carbon getter for maintaining the vacuum to the point that vacuum could not be maintained long-term without the pumping of a cold-cathode gauge. This paper will detail this vacuum issue along with some experiments done to show the pumping rates of the carbon getter and cold-cathode vacuum gauges, and describe a light-baffle design for suppressing light from the gauge.

Citation Download Citation

Tom Benedict and Gregory A. Barrick "Unintended consequences on vacuum hold time with conversion to PolyCold closed-cycle coolers", Proc. SPIE 8450, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II, 84504M (13 September 2012); https://doi.org/10.1117/12.926428

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available