Environmental control system for Habitable-zone Planet Finder (HPF)

Fred Hearty, Eric Levi, Matt Nelson, Suvrath Mahadevan, Adam Burton, Lawrence Ramsey, Chad Bender, Ryan Terrien, Samuel Halverson, Paul Robertson, Arpita Roy, Basil Blank, Ken Blanchard, Gudmundur Stefansson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Scopus citations


HPF is an ultra-stable, precision radial velocity near infrared spectrograph with a unique environmental control scheme. The spectrograph will operate at a mid-range temperature of 180K, approximately half way between room temperature and liquid nitrogen temperature; it will be stable to sub -milli-Kelvin(mK) levels over a calibration cycle and a few mK over months to years. HPF's sensor is a 1.7 micron H2RG device by Teledyne. The environmental control boundary is a 9 m2 thermal enclosure that completely surrounds the optical train and produces a near blackbody cavity for all components. A large, pressure - stabilized liquid nitrogen tank provides the heat sink for the system via thermal straps while a multichannel resistive heater control system provides the stabilizing heat source. High efficiency multi-layer insulation blanketing provides the outermost boundary of the thermal enclosure to largely isolate the environmental system from ambient conditions. The cryostat, a stainless steel shell derived from the APOGEE design, surrounds the thermal enclosure and provides a stable, high quality vacuum environment. The full instrument will be housed in a passive 'meat -locker' enclosure to add a degree of additional thermal stability and as well as protect the instrument. Effectiveness of this approach is being empirically demonstrated via long duration scale model testing. The full scale cryostat and environmental control system are being constructed for a 2016 delivery of the instrument to the Hobby-Eberly Telescope. This report describes the configuration of the hardware and the scale-model test results as well as projections for performance of the full system.

Original languageEnglish (US)
Title of host publicationGround-Based and Airborne Instrumentation for Astronomy V
EditorsSuzanne K. Ramsay, Ian S. McLean, Hideki Takami
ISBN (Electronic)9780819496157
StatePublished - Jan 1 2014
EventGround-Based and Airborne Instrumentation for Astronomy V - Montreal, Canada
Duration: Jun 22 2014Jun 26 2014

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherGround-Based and Airborne Instrumentation for Astronomy V

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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