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MPMS SQUID
Model MPMS-5, Quantum Design Ltd.
Specification
- Magnetization measurements
- Temperature : 1.8 < T < 400 K
- Field : 0 < B < 5 T
Operation
- Temperature control
- 4.5 < T 400 K
- 1.8 < T < 3 K : Stabilize at 5 K, then set 1.8 K (see details below)
- 3 < T < 4.5 K
- Field control
- No overshoot mode
- Oscillating mode
- Hysterisis mode
Temperature control :
- Normal procedure for the 4.45 (set T; actual T=4.4 K) - 400 K range: simple minded operation works.
- Normal procedure for the 1.8 - 4.5 K range:
- Set 1.8 K, then it takes 40 min to 1.8 K, after collecting liquid at 4.1 K.
- After reaching 1.8 K the temperature can be controlled up to for 1 hour.
- To avoid make sequence as follows (template for this is available in the folder)
- Set 1.8 K, wait for 300 sec to stabilize
- Increase temperature in 0.05 K steps, 120 sec waiting time at each.
- If you wish to control the temperature in the range 2.95 - 4.45 K: If one cools down in 0.1 K step slowly starting from 4.45, one can continuously work in this temperature range, manually.
Maintenance
- Helium transfer : twice / week
- Good to keep He level above 40%.
- Manual for Helium transfer can be found here : https://wiki.epfl.ch/lqm/documents/quantum_design_he_filling.pdf
Field restrictions dependng on He level :
- 50-100% - full field up to 50 kOe can be used.
- 30-50% - field up to 10 kOe (recall level 50 is top of the magnet, 30 the bottom).
- 0-30% - Please do not change the field!
- Before transfer set H=0
Trouble shooting
If the green light doesn't turn on when purging
- Check if your temperature is in ‘stable’ status in which case the green light does not turn on.
- Put some ‘Vacuum Grease’ (white-colored Silicone, in a green-white tube) on the movable rod to enhance the vacuum seal.
If the sample straw is detached from the probe inside the SQUID
- Prepare with the empty stick at the end putting kapton tape in an oval or conical shape, set the VTI temperature to 300 K (otherwise the frozen straw may break while touching), then do a gentle "fishing".
References
D:\QdMpms\Refs\MPMS Guidance 2016 1109.docx
D:\QdMpms\Refs\MPMS Troubleshoot 2016 1109.docx
More useful stuff in D:\QdMpms\Refs\