MAGNET

Operate and Control

First test with 50Amps (~5.7T) worked!

• Power Supply : OXFORD IPS 120-10 (Max.12 Amp @10Volt)
  • Software Remote-control: IPS_120-10_v03.vi
  • ! Change of Range when increasing the current at ~4.3A, when decreasing at ~3.4A! Don't get scared by the noise :)
• Upper Magnet, Connection on window side of cryo. Power-cable are marked red (+) and blue (-).
• Persistent current switch:
  • Upper magnet - BOX VII, X9:1/4 ,R_Heater(4K)=135${\Omega }$.
  • I_Heater=55mA. The TVL-10 is used as current supply.
• The region of the experimental platform between the first nuclear stage and the dilution refrigerator is compensated to 5mT when both magnets are at their full field.

Magnetisation and Demagnetisation Procedure

• After ramping the magnet the first nuclear stage must be precooled again. The temperature dependence varies as T~t^-1/3.
• The first nuclear stage was demagnetized by reducing the field in steps by a factor of 2 to a final field of few mT.
• Sweep Rate B>0.5T : R=2T/h.
• Sweep Rate B<0.5T : decrease by a factor of 2 proportional to the field.

Upper Magnet UMM

• B_max = 8T, diameter 100mm.
• I/B-Conversion: B(I) = 0.099 T/A * I[A] , ( 80.68 A = 8 T )
• Sweep Rate: 1 T/h = 10 A/h = 0.167 A/min

Lower Magnet LMM

• B_max = 9T, diameter 50mm.
• I/B-Conversion: B(I) = 0.115 T/A * I[A] , ( 78.4 A = 9 T )
• Sweep Rate: 1 T/h = 8.7 A/h = 0.145 A/min

Connection

• To Power supply: M6 (#13 box wrench, #6 Allen key).
• To Upper Magnet: Connection on window side.
• To lower magnet: Connection on door side of the cryostat.
• AMP-Plug (connected witch BOX VII): Control of persistent current switch, read-out of two Pt-100, heater

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  Connection to upper magnet.

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  Connection to lower magnet.

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  Black AMP-Plug.

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  Installing the magnet with three supporting rods.

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  Connection of the current wiring at the rear panel of the power supply.