Magnet Energization Procedure
From Hall A Wiki
Ramping the magnet is to be done only by target experts
Ramp Up Procedure
Restrictions:
- DO NOT exceed rate limits listed below − magnet can quench
- DO NOT allow persons with medical implants near magnet − death can occur
- AVOID the need for a fill during ramping - warm gas can cause quench
- Ensure safety prerequisites for magnet ramping are met.
Procedure: Instructions from Counting House which assumes: The magnet power supply is on and a sweep for magnetic objects from an area within 4m of the magnet has already been done
- Put PDP in "Monitor," if necessary, to allow updates from users
- Push "Unlock Magnet Controls" button in the Polarization Display Panel, PDP
- Verify that there is no current in the leads (Power supply icon, far left)
- Push "Hold" button
- Hit "Heater On" button and confirm this action in the dialog box that presents itself
- Wait until timer counts down to zero (maybe I little more)
- The magnet must be ramped up in steps with the correct current rates, PDP should not allow you to exceed these rates, but be mindful.
For 2.5T Set the Setpoint to 60.9135A and Setrate to 3.0A/min. (Only one step) For 5.0T there are four steps:
- A.) Setpoint: 80A Setrate: 3.0A/min
- B.) Setpoint: 100A Setrate: 2.0A/min
- C.) Setpoint: 115A Setrate: 1.0A/min
- D.) Setpoint: 121.6A Setrate: 0.5A/min
At each step enter the Setpoint and corresponding Setrate then press To SETPOINT when the current has been reached press HOLD and change value to the Setpoint and Setrate for the next step
- After each change of Setppoint and Setrate check the Magnet Control display in PDP to make sure Labview is reading in correctly
- Press "Hold"
- If persistent mode is not desired, stop here
- Wait for 30 seconds
- Press the "Heater Off" button
- Wait until timer counts down to zero
- To ramp down leads, press "To Zero" button
- Hit "Lock Magnet Controls" button
Ramp Down Procedure
- Hit "Unlock Magnet Controls" button in the Polarization Display Panel, PDP
- Verify the Shim Heater is On (indicator in PDP and camera on PS). This must always be On!
- Verify the Switch heater is OFF
- Put PDP in "Monitor," if necessary, to allow update of switch and shim status
- If necessary, Ramp the Power Supply to the Magnet Current
- Type the value of the magnet current (this is in Amps) into the "Setpoint" box
- Press "To Setpoint"
- Wait for the PS current to reach the Magnet current
- Hit "Heater On" button and confirm this action in the dialog box that presents itself
- Ensure the Heater On status with cameras on the PS and the indicator in PDP
- Wait until timer counts down to zero
- If the countdown starts before the indications, wait at least 30 seconds from the time the heater is on, ignoring the count-down
- Set the first Setpoint and Setrate values. PDP should not allow you to exceed these rates, but be mindful.
- Type the value 0.30 (this is in Amps/min) into the "Setrate" box
- Type the value 72.0 (this is in Amps) into the "Setpoint" box
- Hit the "To Setpoint" button
- Monitor the Voltage in the Coil and Leads (camera, PDP)! A high voltage is a sign of a coming quench.
- If it is increasing rapidly or exceeds 7 V, press "Hold"!
- Wait for magnet to reach 72.0 A (20 min)
- Press "Hold"
- Set the Setpoint and Setrate values for the next current step:
- Type the value 0.60 into the "Setrate" box
- Type the value 60.0 into the "Setpoint" box
- Press "To Setpoint"
- Wait for magnet to reach 60.0 A (20 min)
- Press "Hold"
- Set the Setpoint and Setrate values for the last current step:
- Type the value 1.20 into the "Setrate" box
- Type the value 0.0 into the "Setpoint" box
- Wait until magnet current reaches zero (45 min)
- Hit the "Hold" button
- Hit the "Heater Off" button
- Ensure the Heater Off status with cameras on the PS and the indicator in PDP
- Wait until timer counts down to zero
- If the countdown starts before the indications, be sure to wait at least 30 seconds from the time the heater is off, ignoring the count-down
- Hit "Lock Magnet Controls" button