Operations

To Ramp Up

1. Confirm that the shim PS is powered ON (if you can go in the hall).
2. Press "To Zero".
3. Turn on the main and shim switch heaters.
4. Confirm that the two LEDs on the shim PS are ON (if you can go into the hall).
5. Set "2 A/m" and "45 A".
6. Press "To Set".
7. Wait until the current becomes the SP (23 minutes).
8. Set "1 A/m" and "63 A".
9. Press "To Set".
10. Wait until the current becomes the SP (18 minutes).
11. Set "0.5 A/m" and "74.78 A".
12. Press "To Set".
13. Wait until the current becomes the SP (24 minutes).
14. Switch to the persistent mode, if you want.

Reference: UVA elog 154

To Switch to Persistent Mode

1. Turn off the main and shim switch heaters.
2. Press "To Zero".
3. Wait until the current becomes 0 A (4 minutes).   The ramp rate is slow at the beginning.

To Switch from Persistent Mode

1. Confirm that the shim PS is powered ON.  If not, turn it on and check why it was off.
2. Confirm that the main and shim switch heaters are OFF.  If not, something is wrong.
3. Set 74.78 A.  Step-by-step??

4. Confirm that "Clamped Rate Limit Quench" is not red.

5. Confirm that the PS attains HOLD, once the output current reached at the SP.

To Ramp Down

1. Switch back from the persistent mode, if necessary.
2. Wait for 20 seconds then turn on the "Heater ON".
3. After Set the current at 63.0 Amp and set rate at 0.5 Amp/min then go to Home and then press in the "To Set" this shows "Rate limit" on the home screen.
4. After reached at 63.0 Amp.
5. Set current at 45 Amp and set rate at 1 Amp/min and goto the main screen wait 20 seconds and then press on "To Set".
6. After reached at 45 Amp. 
7. Then set current at 0 Amp and set rate at 2 Amp/min and then go to the home screen wait for 20 seconds and then select "To Set".
8. Once it reached at 0 Amp this will goes to "Hold" automatically.
9. Wait for 20 seconds and then turn of the "Heater OFF" And Turn off the Shim power Supply. 

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The following procedures suppose that you use the remote control interface (i.e. Cryo Control Panel; CCP).  When you use the front panel of the magnet PS, some button operations are different.

Precautions

• The magnet LHe level is so high (>20%??) that LHe remains even if soft quench happens.
• A time to ramp up/down the magnet should be planned in advance, since it takes at least 1.5 hours.
• You should remember that any deviation from the standard procedure might cause quench.
• You are expected to know what should happen at each step and confirm that it happened.  You had better go through this procedure with another person who has already carried it out.
• You should search for any indication of quench during the operations, such as error messages on the magnet PS, sudden changes of Tank B, Coil T, Coil B, the magnet pressure, etc.
  • You can use this chart preset: https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/magnet_ramp.php

Unlocking Controls

All controls on VI are usually locked, to avoid mis-operation.  When you need controls, you have to click the "All Controls: Locked" button.  It is preferable to apply the lock when you finished controls.

Image Added

Procedures

(A) To Ramp Up

(B) To Switch to Persistent Mode

(C) To Switch from Persistent Mode

(D) To Ramp Down

Documents

• ORC 2049 - ORC of Super conducting magnet electronic connectors (in the target cave)
• oxford_seppo_magnet_cryostat_handbook.pdf
• oxford_seppo_work_notes.pdf

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