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2 slot cryostat status - MICE

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					Russ Rucinski, Fermilab, March 29,
               2005
• Commissioning is underway!
  –   2 Cassettes installed on 3/18.
  –   Sensors and control heater mounted.
  –   Multi-layer super insulation blankets on.
  –   Leak checking of vacuum jacket – passed.
  –   Leak checking of cassette space – passed.
  –   Cryostat is in place and hooked up.


                  Russ Rucinski, Fermilab, March 29,
                                 2005
• Initial cool down last Friday 3/25. Started late in
  the day, saw that it would cool, started debugging
  temperature sensor readout. Ran for 2 hours.
  Warmed up over the weekend.
• Started cooling on Monday 3/28 at 7:30 am, and
  have been cooling ever since (32 hours now).
   – Station 1 at 54 K. (more or less stable)
   – Station 2 at 16.5 K. (slowly decreasing)



                    Russ Rucinski, Fermilab, March 29,
                                   2005
• Sensors 1 & 2 are redundant 100 Ohm Allen Bradley
  carbon resistors. They are on stage 2 cold head and
  thermal link. They agree to a few tenths of a Kelvin.
• Sensor 3 is a silicon diode on the upper intercept.
• Cooling rate had slowed to -0.1 K/hr earlier today. But
  now at -0.4 K/hr. Maybe attributed to isolating the
  vacuum jacket from the turbo cart, or lowering lid heater
  setpoint by 5 C, or due to something else.




                    Russ Rucinski, Fermilab, March 29,
                                   2005
Russ Rucinski, Fermilab, March 29,
               2005
• Plans
   –   Continue to cool, and obtain coldest temperatures.
   –   Read out cassette temperature sensors independently.
   –   Get heater control loop functioning.
   –   Install low cassette space pressure alarm.

• If Problems:
   –   Capacity issue? Run without thermal link to cassette.
   –   Heater attachment location may be suspect.
   –   Sensor self heating issue?
   –   More MLI on sides needed? (shell a few C cold on sides)



                        Russ Rucinski, Fermilab, March 29,
                                       2005
Russ Rucinski, Fermilab, March 29,
               2005
                                                        Sensor 2, thermal link
 Sensor 1 – cold end


Sensor 3, upper

                                                             Control heater
                       Russ Rucinski, Fermilab, March 29,
                                      2005

				
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