Heike R2014-00 R68

First RUN since more than one year!!!

NEW

• New Switch & Relay Box for a easier and better operation of the persistent current switches of the current lines and both magnets.

• HF coax wiring for the Paddle experiment: Two Semi rigid coax cables(Type: SC-160/50-NbTi-NbTi) connecting the experiment mounted underneath the Cu-Stage with the heat sinks at the mixing chamber (Coax #5 & #6). With the help of an "extender", made of a long silver rod, the experiment is placed in the centre of the lower magnet and can be exposed to a magnetic field up to 9T.

• HF coax wiring for the Echo experiment leading from the heat sink at 4K (Coax #2 & #4) to a heat sink at the mixing chamber. The Echo Experiment is mounted on the top side of the Cu-Stage and connected with superconducting semi rigid coax cables (Type: SC-160/50-NbTi-NbTi) with this heat sink.

EXPERIMENTS

• Thermometry: Noise Thermometer and Pt-NMR Thermometer
• Paddle Experiment: Zr₅₅Cu₃₀Al₁₀Ni₅ (M. Hempel)
• Echo Experiment: BK-7 (M. Wolter)

TIME TABLE

Bottles of Antikal.

Bigger than 5µ!.

Cheers!.

• 28.01.2014: FIRST DAY - CLOSING
  • Closing cryostat.
  • 15:30 : Start pumping VC with VP.
  • 17:40 : Stop pumping VC, VP off: p_VC~0.3mbar. Close valves, stop pump.

• 29.01.2014 : SECOND DAY - CLEANING & LEAK TEST
  • 08:30 : p_VC~3.2mbar.
  • 09:45 : Start pumping VC again for leak testing.
  • 10:30 : Cleaning cooling water circulation since it's blocked again ... :( (see photos on the right!)
  • 14:50 : Leak Test: Q_L<10^-10mbar*l/sec (with DP running)
  • 15:00 : Cleaning/pumping lines.
  • 16:00 : Start pumping VC with DP
  • 19:00 : Stop pumping VC, DP off: 2*10^-3mbar

• 31.01.2014 : THIRD DAY - CLOSING DEWAR, MOUNTING MAGNET
  • TEST PADDLE EXPERIMENT: working! See resonance at room temperature!

• 3.02.2014: FOURTH DAY - PRECOOLING WITH LN
  • 08:30 : Start cleaning circulation line, start pumping VC for exchange gas
  • 10:15 : Stop pumping circulation line. Start pumping both cold traps. p_VC~3*10^-3mbar. Cleaning 1K-pot & Dewar.
  • 10:45 : p_VC~3*10^-3mbar. Then fill in exchange gas to 3 mbar.
  • 11:12 : Start filling LN (60l can)
  • 16:30 : T_Si~209 K, T_Magn,top~189 K, T_Dewar~78 K, p_VC=1.7 mbar
  • Continue filling LN overnight...

• 4.02.2014: FIFTH DAY - FILLING LH
  • 08:20 : T_Si~130 K, T_Magn,top~131 K, T_Dewar~131 K, p_VC=1.1 mbar. Start pumping nitrogen and clean with helium gas. Do not forget to clean 1K pot!
  • 09:40 : 1^st He can --> ~68l
  • 11:45 : 2^nd He can --> ~95.2l. T_Si~80 K, T_Magn,top~50 K, T_Dewar~10 K, p_VC=4.5*10^-1mbar.
  • 12:35 : T_Dewar~4 K, T_Si~63 K. Switch off 1K-Pot pump and close 1K2, 1K3.
  • 13:40 : T_Si~4 K. Pump VC (14:00)
  • 14:37 : 3^rd He can --> ~88l.
  • 16:10 : 4^th He can --> ~46l.

Total helium consumption: ~297.2l

• 5.02.2014: SIXTH DAY - TESTING MAGNET
  • 08:00 : T_Si~4.85 K, p_VC=1*10^-5mbar. He level ~48%
  • 08:18 : Close VC1, switch off DP.
  • 08:50 : Close VC3 & VC4, switch off FP2.

• XX.XX.2014: THIRD DAY - MIX IN
  • XX:XX : Status = p_VC=??*10^-5mbar, T_MC,RuOx=???, T_MC.Si=??K
  • XX:XX : Start condensing mix. T₁=683mbar, T₂=695mbar, T₃=0mbar, p₄=973mbar.
  • XX:XX : Close Heat-Switch (I_PCS#4=1.5A, I_H=0.5mA) @ T_RuOx=600mK
  • XX:XX : I_Still=3.0mA, T_RuOx=580mK
  • XX:XX : All mix is in, all pumps are running.

• XX.XX.XX: - RAMP MAGNET

• XX.XX.XX: - DEMAG

• XX.XX.XX: MIX OUT
  • XX:XX : Start filling mix into the tanks.