Instructions for the Luminosity HV

If in doubt, please page the on-call expert at 630-314-7701.
If you have trouble reaching the on-call, try the secondary pager 630-218-4471 or you can contact Michelle Prewitt 409-656-2832.
Questions, comments, and requests can also be sent to d0luminosity@fnal.gov.

Normal Procedures

• If the solenoid is energized and we are in store, the HV should be at 100%.   The luminosity HV is ramped up automatically with the Begin Store command. Please Lock the HV after it has reached the green 'Holding' position.
• When we are out of store, the luminosity HV is normally set to 70%. The luminosity HV is ramped down automatically with the End Store command.
• During a cosmic run, the luminosity HV should remain at 70% or below. (The HV may be set lower due to the solenoid condition or by the experts during long periods of down time.)
• Please note any deviation from normal in the control room log book.
• Note: The luminosity HV percentage can be easily checked in the lower right-hand corner of the lmCaptain gui or at the bottom of the luminosity HVChannel gui on the luminosity computer.

Manually Ramping the Luminosity HV

• Go to the HVC GUI on luminosity console (d0ol100)
• Unlock the channels
• If there has been a trip, Reset
• From the menu bar at the top of the gui, Set to the correct %
• Ramp the voltages
• If any channels are in a 'Paused' state, Resume
• Lock after all channels are in a holding state
• If the HVC (High Voltage Control) GUI is not open, then please start a new one.
• open a new xterm on d0ol100
• setup d0online
• cd /mnt/online/config/lum/hv
• lum.hvc &

Solenoid & Lumi HV

• If the solenoid is off, the luminosity HV should never be above 70%. This is to protect the luminosity system since the gain of the PMTs is affected by the solenoid magnetic field.
• If the solenoid current is changing, the luminosity HV should automatically ramp down to 0%. Please check that the luminosity HV is at 0%. If it is not, ramp it down.
• When the solenoid has reached a stable state (absolute value range of [4553A, 4547A] when on and [-3A, 3A] when off) the luminosity HV can be raised.
• If the solenoid is off and stable,
• and we are in store, ramp the HV to 70% and page the luminosity on-call expert.
• and we are not in store, ramp to 50%.
• If the solenoid is on and stable,
• and we are in store, ramp the HV to 100%.
• and we are not in store, ramp the HV to 70%.
• When the HV is ramped to 0% some channels may enter a 'Paused' state. This is ok. Remember to hit the Resume button after the Ramp button.
• If a store is started with the solenoid off, you must ramp the luminosity HV back down to 70% after the Begin Store command is issued.
• Note that the captain will have to ramp the luminosity HV after the solenoid is turned off or on (no matter if we are in or out of store).
• If the solenoid ramps during a store, please page the luminosity on call expert.

Special Circumstances

• If the AD request the luminosity system to be up and displaying correct information during beam studies, then the HV can be raised to 100% IF the solenoid is energized. Please remember to lower the HV to 70% after the AD studies are completed. Also, please note this request in the elog.
• For periods of long down time, the HV might be set to a lower standby value or even turned off. If beam is not expected within 24 hours, do not change the HV setting without consulting with a luminosity expert first.

Trips

• If a luminosity HV channel trips, paste a picture of the HVC GUI and the Short Term Lum Graph into the log book.
• If you know why the trip occurred (ex. large halo spike), ramp the channel to the correct value and state the reason in the log book.
• If you do not know why the channel tripped . . .
• And you are in store:
• Ramp if less than 8 channels tripped, and then page the luminosity expert
• Page the luminosity expert if more than 8 channels trip and do not reset
• And you are out of store:
• Page the luminosity expert before proceeding.
• To ramp after a trip, Unlock (if necessary), Reset, Set the correct HV percentage from the drop down menu at the top of the GUI, and Ramp. After all channels are ramped Lock.