Heike R2012-09 R67: Difference between revisions

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* 07.09.2012 : Degauss FPD, see log-book at page 234.
* 07.09.2012 : Degauss FPD, see log-book at page 234.
* Testing new noise thermometer ...
* Testing new '''noise thermometer''' ... and it worked!!!!
* 18.09.2012 : '''NEW RECORD!''' Due to the new filter-box design we reached a new record! The crabon thermometer mounted on the mixing chamber reached the highest resistance so far: '''R<sub>MC,CT5</sub>=14.1k{{O}}'''. Referred to the old Bayreuth-Calibration this is about 9 mK, corresponding to a our new calibration table (see log book p.139) this is about ~6 mK. Nevertheless even this temperature seems to be too high since the RuOx-thermometer already shows a temperature below 5.9mK (lowest limit of its calibration) at ~11k{{O}} of the crabon thermometer. It is also remarkable that we reached this high resistance while we used the LR-700 multiplexer. Prior to this using the multiplexer always showed up ugly disturbance of the read out resistance values.
* 18.09.2012 : '''NEW RECORD!''' Due to the new filter-box design we reached a new record! The crabon thermometer mounted on the mixing chamber reached the highest resistance so far: '''R<sub>MC,CT5</sub>=14.1k{{O}}'''. Referred to the old Bayreuth-Calibration this is about 9 mK, corresponding to a our new calibration table (see log book p.139) this is about ~6 mK. Nevertheless even this temperature seems to be too high since the RuOx-thermometer already shows a temperature below 5.9mK (lowest limit of its calibration) at ~11k{{O}} of the crabon thermometer. It is also remarkable that we reached this high resistance while we used the LR-700 multiplexer. Prior to this using the multiplexer always showed up ugly disturbance of the read out resistance values.
* New read-out setup of the FPD! See log-book for further details. We successfully managed to see all five fix-points!
* New read-out setup of the '''FPD'''! See log-book for further details. We successfully managed to see all five fix-points!
* We improved Pt '''NMR PLM-4 Setup'''. We also customized the variable PLM-4 gain. The original value of Gain 50 is now an amplification of a factor a 3!!




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* Disconnect RuOx from BOX VI:X2! Connect to BOX I: X7 since using BOX VI seems to cause parasitic heating based on coupling 4.5kHz frequency into the cryostat.
* Disconnect RuOx from BOX VI:X2! Connect to BOX I: X7 since using BOX VI seems to cause parasitic heating based on coupling 4.5kHz frequency into the cryostat.
* Build up / create a kind of switch-box to improve handling the different persistent current switches!
*
* Renew FFT-Software and computer for a better and faster Noise-thermometer read-out :)
*

Latest revision as of 07:38, 22 January 2013

NEW

  • Renewed and improved noise thermometer.
  • The wiring for four Double-Channel-Squids is installed.
  • Two more stainless steel Coax-Cables are installed with their own port at room-temperature. The are numbered #5 and #6. Up to now they end at the mixing chamber and are connected to each other.
  • Two semi-rigid coax-cables were installed, too.
  • Filter-boxes I, II and VI were improved by adding a second coil at the input (cryo-end) of the filter circuit. The coils were manufactured by WĆ¼rth Electronik, Part No. 744221, 2000H; 600mA; 0.42


TEST

  • 07.09.2012 : Degauss FPD, see log-book at page 234.
  • Testing new noise thermometer ... and it worked!!!!
  • 18.09.2012 : NEW RECORD! Due to the new filter-box design we reached a new record! The crabon thermometer mounted on the mixing chamber reached the highest resistance so far: RMC,CT5=14.1k. Referred to the old Bayreuth-Calibration this is about 9 mK, corresponding to a our new calibration table (see log book p.139) this is about ~6 mK. Nevertheless even this temperature seems to be too high since the RuOx-thermometer already shows a temperature below 5.9mK (lowest limit of its calibration) at ~11k of the crabon thermometer. It is also remarkable that we reached this high resistance while we used the LR-700 multiplexer. Prior to this using the multiplexer always showed up ugly disturbance of the read out resistance values.
  • New read-out setup of the FPD! See log-book for further details. We successfully managed to see all five fix-points!
  • We improved Pt NMR PLM-4 Setup. We also customized the variable PLM-4 gain. The original value of Gain 50 is now an amplification of a factor a 3!!


TIME TABLE

  • 30.08.2012: FIRST DAY - CLOSING, CLEANING & PRE-COOLING
    • Closing cryostat and dewar. Cleaning/pumping lines.
    • Exchange gas pVC~3mbar.
    • 17:57 : Pre-cooling with 50l LN.


  • 31.08.2012: SECOND DAY - LIQUID HELIUM
    • 09:00 : Status = TDewar=155K, TMagn,l=152K, pVC=0.78mbar
    • 10:00 : Start filling LHe
    • 15:10 : During 3rd can (after ~ 230 LHe in total): TRuOx=4.6K, pVC=3.3*10-3mbar
    • 15:58 : Pump VC
    • 17:15 : He 100%, LHe in total ~318l
    • 18:45 : Stop pumping VC, pVC=4.7*10-5mbar


  • 07.09.2012: THIRD DAY - MIX IN
    • 09:25 : Status = pVC=2.9*10-5mbar, TMC,RuOx=4.08, TMC.Si=4.17K
    • 09:40 : Start condensing mix. T1=683mbar, T2=695mbar, T3=0mbar, p4=973mbar.
    • 12:30 : Close Heat-Switch (IPCS#4=1.5A, IH=0.5mA) @ TRuOx=600mK
    • 12:40 : IStill=3.0mA, TRuOx=580mK
    • 14:30 : All mix is in, all pumps are running.


  • 03.10.2012: - RAMP MAGNET
    • 21:28 : Magnet armed and dangerous IM=40A


  • 18.10.2012: - DEMAG
    • 10:12 : Start DEMAG. Start conditions TNMR~11mK


  • 31.10.2012: - RAMP MAGNET
    • 15:38 : Magnet armed and dangerous IM=40A, TRuOx~70mK


  • 07.11.2012: - DEMAG
    • 09:50 : Start DEMAG. Start conditions TNMR~15.5mK


  • 13.11.2012: MIX OUT
    • 14:15 : Start filling mix into the tanks.

TO DO

  • Disconnect RuOx from BOX VI:X2! Connect to BOX I: X7 since using BOX VI seems to cause parasitic heating based on coupling 4.5kHz frequency into the cryostat.
  • Build up / create a kind of switch-box to improve handling the different persistent current switches!
  • Renew FFT-Software and computer for a better and faster Noise-thermometer read-out :)