Difference between revisions of "Barrel Calorimeter Expert"

From Hall D Ops Wiki
Jump to: navigation, search
(LED Pulsing Sequence for Production)
(LED Pulsing Sequence for Production)
Line 31: Line 31:
  
 
===LED Pulsing Sequence for Production===
 
===LED Pulsing Sequence for Production===
4/8/2016. We are currently taking BCAL LED triggers during production, but the pulsing sequence is asynchronous to starting and stopping runs. The LEDs are being pulsed using a stand-alone script, which can be run by
+
4/8/2016. We are currently taking BCAL LED triggers during production, but the pulsing sequence is asynchronous to starting and stopping runs. The script that controls the pulsing sequence can be started and stopped from the BCAL LED pulser GUI. The script can be accesed directly by
 
* Open a terminal and login to hdops@gluon02-05
 
* Open a terminal and login to hdops@gluon02-05
 
* cd $DAQ_HOME/tools/bcal_column_pulsing
 
* cd $DAQ_HOME/tools/bcal_column_pulsing

Revision as of 14:53, 8 April 2016

The Barrel Calorimeter

The barrel calorimeter (BCAL) is a lead-scintillating fiber matrix readout with 3840 S12045 Hamamatsu multi-pixel photon counters (MPPCs). The MPPC light sensors operate a bias voltage less than 76 V. Liquid coolant is circulated through the readout assemblies to set and maintain the temperature of the sensors at their operating temperature between 5 and 25 degrees C.

Routine operation

Instructions for shift personnel are available in the Barrel Calorimeter instructions for shift personnel.

Voltage Setting for Specific Overvoltage and Temperature

Fig. 1. Graphical interface for setting the voltages on the BCAL. Indicated are the pulldown menus for retrieving saved voltages from a file and the menus for turning the voltages on and off.

Changes to the voltage settings are only allowed by an expert, or under his/her guidance. The bias voltages for the MPPC sensors can be set using the GUI show in Fig. 1. The bias settings must be set separately for upstream and downstream. For upstream, use the "ALL U Bias" button to select the menu and choose "BCAL U: Set Bias Parameters." Set the "ramp up/down"= 5A/s, "Set Voltage Offset" (overbias) to the desired value (nominal=1.2 V), then the "Temperature for Voltage Settings" to the desired value (nominal=18 deg C). A <carriage return> must be entered for the value to register. Once complete, click on the "Set Voltage" button. Wait for the rainbow "disk" to finish turning (patience, it takes time to load all values). If the voltages are already on, you are done, otherwise you need to use the "BCAL U: Turn ON Bias Channels" menu item to turn them on. The voltage read back and the current draw of each channel are histogramed and plotted at the bottom of the GUI. When all voltages are on at their set values, the display turns green.

Saving and Comparing Save/Restore Files

Specific voltage settings can be saved (from electronics to file) or restored (from file to electronics). This is done via the "Save/Restore" button on the top right of the GUI. The files are automatically saved with the date/time to /gluex/data/burt/voltages/BCAL_BIAS/. We have renamed the files incorporating the date/time temperature and 10 times the overvoltage (to avoid an additional "." in the name). A soft link is created in that directory to point to the nominal file for the current run. The voltages from different files can be compared using the script compare_snap_voltages.C which is located in /gluex/Subsystems/BCAL/scripts.

Chiller Operation

The chiller temperature should be set to 2 degC less than the desired SiPM temperature. The chillers are normally in 'remote' mode. (You can still change the temperature manually). To change the 'set' temperature, use the up/down arrows on the front key pad to the desired temperature. The values are in deg F. Wait for the 'readback' temperature to settle to the 'set' value, as it may overshoot at first. At startup it may be necessary to pull the reset (green) switch forward that is accessed through the hole on the side of the chiller closest to the front.

LED Runs for BCAL Checklist

LED Pulsing Sequence for Production

4/8/2016. We are currently taking BCAL LED triggers during production, but the pulsing sequence is asynchronous to starting and stopping runs. The script that controls the pulsing sequence can be started and stopped from the BCAL LED pulser GUI. The script can be accesed directly by

  • Open a terminal and login to hdops@gluon02-05
  • cd $DAQ_HOME/tools/bcal_column_pulsing
  • BCAL_pulsing.py >& /dev/null & # start program in the background

This command will start an infinite loop cycling through preset configurations of the LED pulser, which are specified in the file 'config'. This file specifies the pulsing frequency, width of LED trigger pulse, number of pulses per cycle and the list of LED bias voltages used for each configuration. A configuration is specified by the LED column number (4) and the upstream/downstream LED (2) and the LED bias setting. The file contents is currently as follows:

HDOPS gluon05:bcal_column_pulsing> more config
freq          1 #Hz
width         200 #ns
npulses       60
led_bias_list 6.2,6.7 #V

To terminate the looping sequence, one may exit using <cntrl>-C at the terminal if it is running in the foreground. The script starts and stops looping depending on the EPICS variable BCAL:pulser:auto_pulsing_stat. The variable can be set or read from the command line as

  • caput BCAL:pulser:auto_pulsing_stat 1
  • caget BCAL:pulser:auto_pulsing_stat

LED Occupancy Runs

Up to now, the DAQ runs are taken independently using the local master trigger interface (TI) for north and south, but should be consolidated by feeding the LED triggers to the trigger supervisor (TS).

  • The checklist entries for the 2016 spring production run are record in Log Entry 3373213.
  • The checklist entries for the 2015 spring commissioning run are recorded in Log Entries 3322823 and 3322905.
  • The checklist entry for the fall 2014 commissioning run is recorded in Log Entry 3297440.

Data were first taken with all LEDs on so that the timing could be checked. Once offsets were adjusted, data were taken using Orlando's script (BCAL_test.py) to pulse the LED. (More information can be found at BCAL DAQ Instructions). The following procedure was followed.

  1. Make sure that SiPM and LED voltages are off
    • Turn off SiPM bias voltage
    • Turn off LED bias voltage
    • Make sure no triggers are enabled or running.
  2. Start DAQ system.
    • Complete prestart/start sequence, leaving system ready and waiting for triggers
  3. Open a terminal and login to hdops@gluon02-05
    • cd $DAQ_HOME/tools/bcal_pulse_sequence
    • BCAL_test.py -s U -q 2,3 -n 10 -b 7 // Run the upstream LED pulser, quadrants 2 and 3 (south side), 10 pulses per setting and (large) bias of 7 V.
    • BCAL_test.py -s D -q 1,4 -n 10 -b 7 // Run the downstream LED pulser, quadrants 1 and 4 (north side), 10 pulses per setting and (large) bias of 7 V.
    • BCAL_test.py –h // Help option
  4. The script with the above arguments should loop through a total of 320 triggers (10 pulses x 4 voltages x 4 columns x 2 quadrants).
    • End run

Status Occupancy Plots

After the raw data were taken, the following procedure was used to generate root files starting from the /gluex/Subsystems/BCAL/data/ directory:

  1. generate root file to dump wave forms
    • hd_root -PPLUGINS=DAQTree /gluonraid2/rawdata/active/RunPeriod-2015-01/rawdata/Run002514/hd_rawdata_002514_000.evio -o /gluex/Subsystems/BCAL/rootfiles/hd_rawdata_002514_000.root
    • display waveforms
    • root [0] .L /gluex/Subsystems/BCAL/scripts/dump_tree_waveform_dalton.C+
    • root [0] dump_tree_waveform_dalton("/gluex/Subsystems/BCAL/rootfiles/hd_rawdata_002514_000.root");
  2. generate root file to create occupancy plots
    • hd_root -PPLUGINS=DAQTreeBCAL /gluonraid2/rawdata/active/RunPeriod-2015-01/rawdata/Run002514/hd_rawdata_002514_000.evio -o /gluex/Subsystems/BCAL/rootfiles/hd_rawdata_002514_000_status.root
    • create occupancy plot for FADCs
    • root [0] .L /gluex/Subsystems/BCAL/scripts/SiPM_Test_fADC.C+
    • root [0] SiPM_Test_fADC("/gluex/Subsystems/BCAL/rootfiles/hd_rawdata_002514_000_status.root");
    • root [0] c1->SaveAs("/gluex/Subsystems/BCAL/plots/LED_status/hd_bcal_n-led_up_mode8-ADC_R2514.pdf");
  3. create occupancy plot for TDCs
    • root [0] .L /gluex/Subsystems/BCAL/scripts/SiPM_Test_TDC.C+
    • root [0] SiPM_Test_TDC("/gluex/Subsystems/BCAL/rootfiles/hd_rawdata_002514_000_status.root");
    • root [0] c1->SaveAs("/gluex/Subsystems/BCAL/plots/LED_status/hd_bcal_n-led_up_mode8-TDC_R2514.pdf");

Remote Control PDU

Fig. 2. Screen shot of the PDU web interface.


The bias (ISEG) and low voltage (MPOD) supplies providing power to the SiPMs are plugged into remotely controllable power distribution units (PDUs). This allows us to recycle the power to the crates via a web interface. Each of the four ISEG/MPOD crates is plugged into its own PDU. At the present time, only the first output of the distribution strip is used. The following PDUs are being used, given by the name of the rack followed by -pdu.

  • n1-1-pdu
  • n1-6-pdu
  • s1-1-pdu
  • s1-6-pdu

The remote access to the crate is via a web browser in the Counting House pointing to the name of the PDU (e.g. type s1-1-pdu into browser and confirm with user/pass=admin/admin). See the screen shot of the web interface. To cycle the power

  • Click on the Actions, then Loads button.
  • Highlight the first line (Load 1). The On/Off/Cycle buttons should become enabled
  • Click on the Off and confirm preference. It will take about half a minute to complete the command (patience!). After "Output Current Changed" message appears under Alarm Status, the status should turn from 'On' to 'Off', then message disappears.
  • Repeat reverse action to turn PDU input back on.

Restarting memory for discriminator scalers

These are the instructions from Paul (2/8/2016): If the discriminator scalers are showing zero, reboot the procServ's on these crates. There's no way to do this through the GUIs. In the meantime, you can ssh to the ROC in question, and do:

  • telnet localhost 25061 (connect to procServ)
  • ctrl + X (reboot procServ)
  • ctrl + ]
  • quit (exit the telnet connection)

External Cosmic-Ray Trigger

The external cosmic-ray trigger was setup using some scintillation counters located above and below the magnet yoke to signal the passing of cosmic rays through the central detectors. Log Entry 3275972 and Log Entry 3285969 contain detailed information about the setup. To control the high voltage using the CAEN power supply use the following procedure starting from a terminal on the local network:

  • telnet u1-9-top 1527
  • login: user/user
  • Use 'tab' to move from one column menu heading to another.
  • Use keypad 'up' and 'down' arrows to select submenus under the header. Select Main/Channels to view voltages.
  • Use 'tab' to move back to Main menu, 'down' key to 'Log Out' and exit

Expert personnel

The individuals responsible for checking that the BCAL is ready to take data and setting its operating parameters are shown in following table. Problems with normal operation of the BCAL should be referred to those individuals and any changes to their settings must be approved by them. Additional experts may be trained by the system owner and their name and date added to this table.

Table: Expert personnel for the BCAL system
Name Extension Date of qualification
Elton Smith 269-7625 May 20, 2014