ComCam Utilities Travis Lange Scott Newbry Camera I&T Mar. 6, 2017

Purpose Define the Interface between SLAC and Tucson ICD for UT to ComCam Sled (Mechanical) Identify Components Required to Operate ComCam Refrigeration Pathfinder with ComCam Preliminary Design for UT

ComCam Utility Requirements From LTS-508 LTS-508-28: 1000mm x 500mm x 500mm max. envelope LTS-508-29: Total mass of utility box < 200kg (including support structure) Goals and Derived Requirements Use common hardware with camera UT Limit use of components with LEDs or displays (and/or make box light-tight) ComCam shall release no more than 200W heat load into TMA plenum during operations (from Camera spec) ComCam Utility Box exterior surfaces follow dome air temp to ±5°C This requirement is ±1°C for the cryostat region

Mechanical Interface Utility Box and ComCam Sled Volume for Utility Box and Refrigeration Pathfinder is same as Camera UT Ø980mm x 1794mm Design will feature plate that mounts to ComCam sled similar to Camera UT Use of wobble plate to manage utility lines entering ComCam Utility Box is undecided Space for utilities and refrigeration pathfinder

Components in Utility Box—Block Diagram

Components in Utility Box—Missing Items Utility Box will also have all components needed to operate Refrigeration Pathfinder Power supply for heat loads Pressure transducers Thermocouple digitizers HCU to control refrigeration pathfinder Vacuum pumps/controllers Scope of utilities needed for refrigeration pathfinder not fully identified

Temperature Control

Sources of Heat for ComCam Utility Box (power dissipated) 500W Power Supply (100W) Cryotel Power Supply (3x 96W) HCU’s (2x 41W) Miscellaneous (130W) Approx. 600W total All components will be thermally controlled with heat exchangers using dynalene Cryostat (power dissipated) Cryotel (3x 480W) Turbo Pump (450W) Scroll Pump (220W) Ion Pump (21W) Filter Changer Bonn Shutter Cryotel will use liquid cooling (dynalene) to remove heat Turbo/Scroll pump are off during operations Ion pump is a steady state source of heat at 21W Much less than 200W requirement

Sources of Heat for ComCam Some heat sources are not mitigated Scroll pump and turbo pump heat (670W) will be released to dome via conduction/convection during start up Radiation shield could improve radiation to dome Liquid cooling of turbo pump would reduce most of transient heat load to environment (is this necessary or a good idea?) Shutter power dissipation Filter Changer power dissipation

Cryostat Layout Credit: Justine Haupt

Remaining Work Prior to PDR

Lots to do Complete block diagram that includes components required for refrigeration pathfinder Define the interface between pathfinder/utility box structure and ComCam sled Allocate space/interface for pathfinder and utility box Create a layout of components in utility box