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Details

Cooling the Dark Energy Camera Instrument.

DE2008932857

Publication Date	2008
Personal Author	Kuhlmann, S.; Onal, B.; Stefanik, A.; Schmitt, R. L.; Cease, H.
Page Count	12
Abstract	DECam, camera for the Dark Energy Survey (DES), is undergoing general design and component testing. For an overview see DePoy, et al in these proceedings. For a description of the imager, see Cease, et al in these proceedings. The CCD instrument will be mounted at the prime focus of the CTIO Blanco 4m telescope. The instrument temperature will be 173K with a heat load of 113W. In similar applications, cooling CCD instruments at the prime focus has been accomplished by three general methods. Liquid nitrogen reservoirs have been constructed to operate in any orientation, pulse tube cryocoolers have been used when tilt angles are limited and Joule-Thompson or Stirling cryocoolers have been used with smaller heat loads. Gifford-MacMahon cooling has been used at the Cassegrain but not at the prime focus. For DES, the combined requirements of high heat load, temperature stability, low vibration, operation in any orientation, liquid nitrogen cost and limited space available led to the design of a pumped, closed loop, circulating nitrogen system. At zenith the instrument will be twelve meters above the pump/cryocooler station. This cooling system expected to have a 10,000 hour maintenance interval. This paper will describe the engineering basis including the thermal model, unbalanced forces, cooldown time, the single and two-phase flow model.
Keywords	Cameras Cooling systems Design Maintenance Meters Nitrogen Orientation Stability Testing Two-phase flow Surveys Meetings
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Fermi National Accelerator Lab., Batavia, IL.; Argonne National Lab., IL.; Ohio State Univ., Columbus.; Department of Energy, Washington, DC.
Supplemental Notes	Prepared in cooperation with Ohio State Univ., Columbus. and Argonne National Lab., IL. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200825
Contract Number	DE-AC02-76CH03000

Cooling the Dark Energy Camera Instrument.

Cooling the Dark Energy Camera Instrument.
DE2008932857

Publication Date	2008
Personal Author	Kuhlmann, S.; Onal, B.; Stefanik, A.; Schmitt, R. L.; Cease, H.
Page Count	12
Abstract	DECam, camera for the Dark Energy Survey (DES), is undergoing general design and component testing. For an overview see DePoy, et al in these proceedings. For a description of the imager, see Cease, et al in these proceedings. The CCD instrument will be mounted at the prime focus of the CTIO Blanco 4m telescope. The instrument temperature will be 173K with a heat load of 113W. In similar applications, cooling CCD instruments at the prime focus has been accomplished by three general methods. Liquid nitrogen reservoirs have been constructed to operate in any orientation, pulse tube cryocoolers have been used when tilt angles are limited and Joule-Thompson or Stirling cryocoolers have been used with smaller heat loads. Gifford-MacMahon cooling has been used at the Cassegrain but not at the prime focus. For DES, the combined requirements of high heat load, temperature stability, low vibration, operation in any orientation, liquid nitrogen cost and limited space available led to the design of a pumped, closed loop, circulating nitrogen system. At zenith the instrument will be twelve meters above the pump/cryocooler station. This cooling system expected to have a 10,000 hour maintenance interval. This paper will describe the engineering basis including the thermal model, unbalanced forces, cooldown time, the single and two-phase flow model.
Keywords	Cameras Cooling systems Design Maintenance Meters Nitrogen Orientation Stability Testing Two-phase flow Surveys Meetings
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Fermi National Accelerator Lab., Batavia, IL.; Argonne National Lab., IL.; Ohio State Univ., Columbus.; Department of Energy, Washington, DC.
Supplemental Notes	Prepared in cooperation with Ohio State Univ., Columbus. and Argonne National Lab., IL. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200825
Contract Number	DE-AC02-76CH03000