Heike R2012-09 R67: Difference between revisions

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= NEW =
= NEW =
* renewed and improved noise thermometer.
* Renewed and improved noise thermometer.
* The wiring for four Double-Channel-Squids is installed.
* 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 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.
* 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 Würth Electronik, Part No. 744221, 2000{{u}}H; 600mA; 0.42{{O}}



=NEW=

* Pt-NMR read-out via two s.s. mini-coax. Signal Coil is connected with port #1 and #3.
* Different capacitances two improve the NMR tank-circuit.




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=TEST=
=TEST=


* 07.09.2012 : Degauss FPD, see log-book at page 234.
* Testing Pt-NMR. Coax #1 and #3 is connected with a special box. Inside this box the inner conductor of coax #1 is grounded and the inner conductor of #3 is feed through. For details see Pt-NMR Log-Book page 20. At first glance it seems like the device works at Curie-Mode.
* 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.
* In spite of many attempts with different setups it isn't possible to measure in the Korringa-Mode with the PLM-4 so far.
* 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!!
* Heating by RF-Signal causes a significant parasitic heat input on the mixing chamber and on the Cu-Stage. Several tests were done to prove this. See e.g. logbook: 16.03. or 22.03.2012.

* '''NEW LOWEST TEMPERATURE ACHIEVED''': '''T<sub>NMR</sub> ~ 85 {{u}}K''' (14.03.)

* New Filter-Design for some Boxes.




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=TIME TABLE=
=TIME TABLE=
[[Image:Icy_transfer-tube.jpg|right|thumb|200px|Icy transfer tube with a sub-prime vacuum :)]]

* 28.02.2012: FIRST DAY - CLOSING, CLEANING & PRECOOLING
⚫
** Closing cyrostat and dewar. Cleaning/pumping lines.
⚫
** Precooling with 50l LN.


* 29.02.2012: SECOND DAY - LIQUID HELIUM
⚫
** 07:50 : Status = T<sub>Dewar</sub>=207K, T<sub>MC,Si</sub>=216K, T<sub>Magn,l</sub>=217K, p<sub>VC</sub>=2.15mbar
⚫
** 09:55 : Start filling LHe
** 17:00 : Status after two cans ('''188.8l LHe''') =T<sub>MC,Si</sub>=80K, T<sub>Magn,u</sub>=50K, p<sub>VC</sub>=0.45mbar



* 01.03.2012: THIRD DAY - '''MIX IN'''
* 30.08.2012: FIRST DAY - CLOSING, CLEANING & PRE-COOLING
⚫
** Closing cryostat and dewar. Cleaning/pumping lines.
⚫
** 08:00 : Status = T<sub>Dewar</sub>=78K, T<sub>MC,Si</sub>=80K, T<sub>Magn,u</sub>=81K, p<sub>VC</sub>=0.67mbar, connect 3<sup>rd</sup> can LHe
** 11:45 : T<sub>MC,Si</sub>=4K, start pumping vacuum vessel.
** Exchange gas p<sub>VC</sub>~3mbar.
⚫
** 17:57 : Pre-cooling with 50l LN.
⚫
** 14:00 : Start condensing mix. '''T<sub>1</sub>=688mbar, T<sub>2</sub>=700mbar, T<sub>3</sub>=0mbar, p<sub>4</sub>=774mbar'''.
** 14:10 : 100% He-Level. Total consumption to reach this level: '''428.2 litres''' (Five cans) .
⚫
** 16:20 : Close Heat-Switch (I<sub>PCS#4</sub>=1.5A, I<sub>H</sub>=0.5mA) @ T<sub>RuOx</sub>=700mK
⚫
** 17:20 : All mix is in, all pumps are running. I<sub>STILL</sub>=3.0mA, T<sub>RuOx</sub>=90mK




* 02.03.2012: 4<sup>th</sup> DAY
* 31.08.2012: SECOND DAY - LIQUID HELIUM
⚫
** 09:00 : Status = T<sub>Dewar</sub>=155K, T<sub>Magn,l</sub>=152K, p<sub>VC</sub>=0.78mbar
** Testing FPD
⚫
** 10:00 : Start filling LHe
** Connecting and Testing Pt-NMR
** 15:10 : During 3rd can (after ~ 230 LHe in total): T<sub>RuOx</sub>=4.6K, p<sub>VC</sub>=3.3*10<sup>-3</sup>mbar
** 15:58 : Pump VC
** 17:15 : He 100%, LHe in total '''~318l'''
** 18:45 : Stop pumping VC, p<sub>VC</sub>=4.7*10<sup>-5</sup>mbar




* 05.03.2012: 1<sup>st</sup> RAMP MAGNET
* 07.09.2012: THIRD DAY - '''MIX IN'''
⚫
** 09:25 : Status = p<sub>VC</sub>=2.9*10<sup>-5</sup>mbar, T<sub>MC,RuOx</sub>=4.08, T<sub>MC.Si</sub>=4.17K
** Satus : Heat switch is closed.
⚫
** 09:40 : Start condensing mix. '''T<sub>1</sub>=683mbar, T<sub>2</sub>=695mbar, T<sub>3</sub>=0mbar, p<sub>4</sub>=973mbar'''.
⚫
** 12:40 : I<sub>M</sub>= 40 A, heat switch closed (1,5 A)
⚫
** 12:30 : Close Heat-Switch (I<sub>PCS#4</sub>=1.5A, I<sub>H</sub>=0.5mA) @ T<sub>RuOx</sub>=600mK
⚫
** 12:40 : I<sub>Still</sub>=3.0mA, T<sub>RuOx</sub>=580mK
⚫
** 14:30 : All mix is in, all pumps are running.


⚫
* 07.03.2012: '''1<sup>st</sup> DEMAG'''
** 11:04 : Open HS, T<sub>i</sub>= 19.6 mK (corresponding to Noise Thermometer), B<sub>i</sub>= 3.96 T
** 19:06 : I<sub>M</sub>= 0.6 A, T<sub>NMR</sub> ~ 389 uK, NT was disturbed by additional noise contribution in the frequency spectrum.


⚫
* 03.10.2012: - '''RAMP MAGNET'''
** 21:28 : Magnet armed and dangerous I<sub>M</sub>=40A


[[Image:Pt-NMR_94uK.jpg|right|thumb|200px|PLM-4 display shows temperature after demag (Curie-Mode)(14.03.12).]]
⚫
* 08.03.2012: 2<sup>nd</sup> RAMP MAGNET
** 12:00 : I<sub>M</sub>= 40 A, heat switch closed (1,5 A)


* 14.03.2012: '''2<sup>nd</sup> DEMAG'''
* 18.10.2012: - '''DEMAG '''
⚫
** 10:12 : Start DEMAG. Start conditions T<sub>NMR</sub>~11mK
** ! Changed setup of PLM-4! See NMR-textbook page 23
** 11:04 : Open HS, T<sub>i</sub>= 14.95 mK (corresponding to Noise Thermometer), B<sub>i</sub>= 3.96 T
** 19:06 : I<sub>M</sub>= 0.1 A, T<sub>NT</sub> ~ 300uK ( caused by disturbances !!! ), '''T<sub>NMR</sub> ~ 85 {{u}}K''' (!!!) in Curie Mode.




* 17.03.2012: 3<sup>rd</sup> RAMP MAGNET
* 31.10.2012: - '''RAMP MAGNET '''
** 15:38 : Magnet armed and dangerous I<sub>M</sub>=40A, T<sub>RuOx</sub>~70mK
** 13:05 : Closing heat switch.
** 13:38 : I<sub>M</sub>= 40 A, heat switch closed (1,5 A)


* 21.03.2012: '''3<sup>rd</sup> DEMAG'''
** 10:43 : Open HS, T<sub>i</sub>= 19.23 mK (corresponding to Noise Thermometer), T<sub>NMR</sub>= 19.045 mK, B<sub>i</sub>= 3.96 T
⚫
** 10:59 : Start Demag: T<sub>NT</sub>= 17.80 mK
** 16:16 : Stop Noise-Thermometer read-out due to massive external distributions by additional noise (SQUID-Radio Moscow :) ).
** 18:50 : I<sub>M</sub>= 0.3 A, T<sub>NMR</sub> ~ 240 {{u}}K in Curie Mode.


* 22.03.2012: '''MIX OUT'''
* 07.11.2012: - '''DEMAG '''
** 09:50 : Start DEMAG. Start conditions T<sub>NMR</sub>~15.5mK
** Some rf-heating tests
⚫
** 14:30 : Start putting mix in tank 1 and 2.
** 18:00 : After using babypump :'''T<sub>1</sub>=688mbar, T<sub>2</sub>=700mbar, T<sub>3</sub>=0mbar, p<sub>4</sub>=1032mbar'''.
** ALL MIX IS DUMPED IN OUR TANKS




⚫
* 13.11.2012: '''MIX OUT'''
⚫
** 14:15 : Start filling mix into the tanks.


{{clear}}
{{clear}}
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=TO DO=
=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.
* Find correct setup of the PLM-4 Korringa-Mode.
* Build up / create a kind of switch-box to improve handling the different persistent current switches!
* Improve Filter-Design!
* Renew FFT-Software and computer for a better and faster Noise-thermometer read-out :)
* Reduce parasitic heating by rf-signals.
* Get rid of SQUID-Radio Moscow :)
* Remove partially plugged flow of cooling water

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 Würth 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 :)
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