Instructions for the Luminosity HV

Contact: Gregor Geurkov

Updated:  August 23, 2001

 

When the solenoid magnet is ON the gain of the PMTs is affected, therefore one has to change the HV to 70% of the max value on the Luminosity HV screen. There is no effect by the Toroid magnet.

When the solenoid is OFF the gain of the PMTs is increased and to reduce damage done by HV supplies in operating over the optimum value voltage should be set to 50% of the max value.

If a channel trips then try to reset it a couple of times. If it doesn’t work then leave it OFF. If more than 5 channels trip then contact Gregor Geurkov or another Luminosity Expert. Record trips in the Luminosity Log book and in the Luminosity e-log.

 

Steps to change HV

Setting Voltage

all PMTs at once.

If the high voltage is already on click on the top of the HV screen on the “Set HV” button and by holding on it drag to the desired value (in % relative of the max)

DO NOT turn OFF HV without ramping down to zero first. There is no STANDBY on Luminosity System.

 

Ramping

all PMTs at once.

Click on the bottom of the panel on the “Ramp” button. Observe how voltages change. If there are trips or it fails the first time check if voltage was selected properly. First click on “Reset” on the top of the panel then try to “Ramp” once again. If the problem remains then contact Luminosity Experts (see below). If individual channels trip then see the next section below.

 

Paused-If the HV value gets paused during ramping then click on the channel under Status column and pick Ramping

Locked-To change the HV if everything is locked simply click on unlock button on the bottom of the GUI

Frozen-If the channel is oscillating or stops ramping above a certain value try to restart the luminosity HV GUI (see below). If problem remains contact Experts.

 

If the Luminosity HV panel dies/freezes (click on “Quit” then) or was “accidentally” closed then to start it again follow these steps. From d0lum xterm window type

cd ~d0lum/operations/config;  ./show_hv &

Click on the top of the screen to “ON” HV on PMTs on. Then follow instructions above on how to select voltages.

 

Luminosity Experts:

Gregor Geurkov (8am-8pm)   Michael Begel               or             Richard Partridge (Th/Fr)

Office: x2638                                                                         Office: x8702

Pager: 630-314-7701                     Pager: 630-218-4836             Pager: 401-751-3869

Cell: 401- 527-4497