Heike R2012-09 R67

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, 2000$\mu$H; 600mA; 0.42${\Omega }$

TEST

• Testing new noise thermometer ...

TIME TABLE

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

• 29.02.2012: SECOND DAY - LIQUID HELIUM
  • 09:00 : Status = T_Dewar=155K, T_Magn,l=152K, p_VC=0.78mbar
  • 10:00 : Start filling LHe
  • 15:10 : During 3rd can (after ~ 230 LHe in total): T_RuOx=4.6K, p_VC=3.3*10^-3mbar
  • 15:58 : Pump VC
  • 17:15 : He 100%, LHe in total ~318l
  • 18:45 : Stop pumping VC, p_VC=4.7*10^-5mbar

• 01.03.2012: THIRD DAY - MIX IN
  • 08:00 : Status = T_Dewar=78K, T_MC,Si=80K, T_Magn,u=81K, p_VC=0.67mbar, connect 3^rd can LHe
  • 11:45 : T_MC,Si=4K, start pumping vacuum vessel.
  • 14:00 : Start condensing mix. T₁=688mbar, T₂=700mbar, T₃=0mbar, p₄=774mbar.
  • 14:10 : 100% He-Level. Total consumption to reach this level: 428.2 litres (Five cans) .
  • 16:20 : Close Heat-Switch (I_PCS#4=1.5A, I_H=0.5mA) @ T_RuOx=700mK
  • 17:20 : All mix is in, all pumps are running. I_STILL=3.0mA, T_RuOx=90mK

• 02.03.2012: 4^th DAY
  • Testing FPD
  • Connecting and Testing Pt-NMR

• 05.03.2012: 1^st RAMP MAGNET
  • Satus : Heat switch is closed.
  • 12:40 : I_M= 40 A, heat switch closed (1,5 A)

• 07.03.2012: 1^st DEMAG
  • 11:04 : Open HS, T_i= 19.6 mK (corresponding to Noise Thermometer), B_i= 3.96 T
  • 19:06 : I_M= 0.6 A, T_NMR ~ 389 uK, NT was disturbed by additional noise contribution in the frequency spectrum.

PLM-4 display shows temperature after demag (Curie-Mode)(14.03.12).

• 08.03.2012: 2^nd RAMP MAGNET
  • 12:00 : I_M= 40 A, heat switch closed (1,5 A)

• 14.03.2012: 2^nd DEMAG
  • ! Changed setup of PLM-4! See NMR-textbook page 23
  • 11:04 : Open HS, T_i= 14.95 mK (corresponding to Noise Thermometer), B_i= 3.96 T
  • 19:06 : I_M= 0.1 A, T_NT ~ 300uK ( caused by disturbances !!! ), T_NMR ~ 85 $\mu$K (!!!) in Curie Mode.

• 17.03.2012: 3^rd RAMP MAGNET
  • 13:05 : Closing heat switch.
  • 13:38 : I_M= 40 A, heat switch closed (1,5 A)

• 21.03.2012: 3^rd DEMAG
  • 10:43 : Open HS, T_i= 19.23 mK (corresponding to Noise Thermometer), T_NMR= 19.045 mK, B_i= 3.96 T
  • 10:59 : Start Demag: T_NT= 17.80 mK
  • 16:16 : Stop Noise-Thermometer read-out due to massive external distributions by additional noise (SQUID-Radio Moscow :) ).
  • 18:50 : I_M= 0.3 A, T_NMR ~ 240 $\mu$K in Curie Mode.

• 22.03.2012: MIX OUT
  • Some rf-heating tests
  • 14:30 : Start putting mix in tank 1 and 2.
  • 18:00 : After using babypump :T₁=688mbar, T₂=700mbar, T₃=0mbar, p₄=1032mbar.
  • ALL MIX IS DUMPED IN OUR TANKS