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
- Sweep for magnetic objects from area within 4m of magnet
- Put PDP in "Monitor," if necessary, to allow update of switch and shim status
- Hit "Unlock Magnet Controls" button in the Polarization Display Panel, PDP
- Verify that there is no current in the leads (Power supply icon, far left)
- Verify the Shim Heater is On (indicator in PDP and camera on PS). This must always be On!
- Hit "Hold" button
- 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 1.20 (this is in Amps/min) into the "Setrate" box
- Type the value 60.0 (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 7.5 V, press "Hold"!
- Lower the rate and try again, ensuring the voltage stays low.
- Wait for magnet to reach 60.0 A (45 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 72.0 into the "Setpoint" box
- Press "To Setpoint"
- Wait for magnet to reach 72.0 A (20 min)
- Press "Hold"
- Set the Setpoint and Setrate values for the last current step:
- Type the value 0.30 into the "Setrate" box
- Type the desired magnet current into the "Setpoint" box
- Currents for full−field and for baseline measurements are on whiteboard
- Wait until magnet current reaches the requested value (20 min)
- Hit the "Hold" button
- If persistent mode is not desired, stop here
- Wait for 30 seconds
- 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
- If we are going to be ramping down the leads, hit "To Zero" button to ramp leads down
- 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