Heike R2010-11 R65

NEW

• Squid-Wiring for one two-stage Squid
• Two Lemo plugs and four coax-feedthroughs on top of cryostat.
• RuOx-000 Thermometer on lower MC platform.
• New Still-heater!! old one was broken? New resitance R_STILL=1.13k${\Omega }$.
• New Noise-Thermometer mounted on Demag-Stage read out by two Squids.

Tests

• Persistent Current Switch between mixing chamber and demag-stage: WORKS!
• Noise Thermometer: WORKS!
• Pt-NMR: DOESN'T WORK! No connection to signal loop.
• New RuOx-Thermometer works well!

Time Table

• 30.11.11: 1st DAY - CLOSING AND PRECOOLING
  • 10:30 : Start closing Cryo
  • 14:00 : Dewar closed , start pumping dewar. All lines pumped, all pumps tested.
  • Exchange gas: p_VC=10mbar.
  • 15:00 : Start filling nitrogen
  • 17:12 : Dewar Pt-100 shows LN. Continue filling.
  • 17:45 : LN vessel remains connected with the cryostat during the night but without any pressure, atmosphere-valve of LN can is open! (T_Dewar=78K, T_MC,Si-Diode=253K, p_VC=3.89mbar, T_Magn,u.=233)

• 01.12.11: 2nd DAY - START COOLING WITH LHe
  • 08:00 : Status: T_Dewar=225K, T_MC,Si-Diode=221K, p_VC=3.4mbar, T_Magn,u.=230K. Continue filling with LN until T_Dewar=78K, continue for 5 minutes.
  • 10:45 : Pump dewar (-0.8bar), float with He from recovery line
  • 11:00 : 1st can of LHe connected, start 1K-pump (T_Dewar=121K, T_MC,Si-Diode=206K, p_VC=3mbar, T_Magn,u.=176K)
  • 13:30 : 2nd can. By a mistake there was only 16 litres of He taken out of the 1st can!
  • 16:00 : 3rd can. 95 litres were taken from 2nd can.
  • 17:30 : Liquid Helium in Dewar! R_Dewar=0.92${\Omega }$!, T_MC,Si-Diode=58K, p_VC=0.24mbar (=7.2K), T_Magn,u.=7K
  • 18:00 : 4th can. 70 litres were taken from 3rd can.
  • 18:30 : 4K! T_MC,Si-Diode=4.1K, p_VC=4.3E-03mbar, R_MC,CT=275${\Omega }$.
  • 19:15 : Disconnect 4th can, 91 litres were taken. R_MC,CT=275${\Omega }$, p_VC=4.1E-03mbar,

-> He consumption: ~272 litres!

• 02.12.11: 3rd DAY - 4K
  • 08:15 : T_MC,Si-Diode=4.1K, R_MC,CT=276${\Omega }$, p_VC=4.8E-03mbar.
  • 08:50 : Pump exchange gas
  • 14:20 : 5th can. After 10 min. first value displayed on He-levelmeter.
  • 15:20 : Stop He-transfer, levelmeter shows 100% (98 litres of He transferred)
  • 15:55 : Stop pumping exchange gas, p_VC=1.7E-05mbar.

• 05.12.11: 6th DAY - MIX IN
  • 07:30 : Testing Noise-Thermometer
  • 09:10 : Start 1K-Pump
  • 09:20 : Start putting mix in, T₁=690mbar, T₂=700mbar, T₃=240mbar
  • Test Heat Switch

• 06.12.11: 7th DAY - MAGNET TEST
  • Test Magnet: 13:20 Start ramping, 15:10 I_Mag=15A

• 07.12.11: 8th DAY - RAMP MAGNET
  • 09:40 : Heat switch closed.
  • 09:55 - 10:45 : Ramp Magnet up to I_Mag=40A.
  • 10:57 - 14:00 : TMPs on.
  • 14:39 : Close PCS of Magnet, ramp current-supply of the magnet down. -> 40Ampere persistent current inside the magnet!!!

• 21.12.11: MIX OUT!
  • 17:15 : Start putting the mix in Tank 1 and Tank 2.
  • 01:15 : MIX in tanks: T₁=687mbar, T₂=700mbar, T₃=0mbar, p₄=813mbar

Checking Filterboxes

• done!
• details will be added :)

TO DO FOR NEXT RUN

• Repair Pt-NMR Signal line.
• Kryo-Log: Improve LR-700 read-out! Add magnet current into cryo-log.