Difference between revisions of "Tagging Spectrometer Shift"
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== Routine operation== | == Routine operation== | ||
| − | The shift crew will be monitoring the detector performance parameters such as the counter rate per channel and detector occupancies | + | The shift crew will be monitoring the detector performance parameters such as the counter rate per channel and detector occupancies. |
Any hot or dead channels have to be recorded in the log file. If the average counter rate significantly deviates (the range will be specified for each shift) from | Any hot or dead channels have to be recorded in the log file. If the average counter rate significantly deviates (the range will be specified for each shift) from | ||
| − | the expected rate, | + | the expected rate, an expert should be called. In the case an alarm system detects the PMT current trip, the PMT high-voltage will be shutoff. The crew should |
| − | + | restore the voltage on the PMT using the GUI interface (see instructions below). If the problem persists the expert should be called. | |
Control and monitoring of the system is accomplished using the Hall D graphical user interfaces (GUI) to EPICS [http://www.epics.org] [http://www.aps.anl.gov/epics]. A description of how to | Control and monitoring of the system is accomplished using the Hall D graphical user interfaces (GUI) to EPICS [http://www.epics.org] [http://www.aps.anl.gov/epics]. A description of how to | ||
Revision as of 14:45, 3 July 2014
Contents
Tagger Hodoscope
The tagger hodoscope consists of 218 scintillator counters which are installed behind the focal plane of the tagger magnet. The light produced in each counter is detected using Hamamatsu R9800 PMTs which are instrumented with JLab's custom designed dividers and divider-based amplifiers. The PMTs are operated at around 950 V. The hodoscope will be used for tuning the orientation of the radiator crystal by measuring the photon beam energy spectrum. This procedure will require involvement of experts and will not be performed by shift crew members. During data taking, the hodoscope will be used to monitor the beam stability.
Routine operation
The shift crew will be monitoring the detector performance parameters such as the counter rate per channel and detector occupancies. Any hot or dead channels have to be recorded in the log file. If the average counter rate significantly deviates (the range will be specified for each shift) from the expected rate, an expert should be called. In the case an alarm system detects the PMT current trip, the PMT high-voltage will be shutoff. The crew should restore the voltage on the PMT using the GUI interface (see instructions below). If the problem persists the expert should be called.
Control and monitoring of the system is accomplished using the Hall D graphical user interfaces (GUI) to EPICS [1] [2]. A description of how to bring up the GUI screens can be found in Section Slow Controls.
Voltage Settings and Control
All PMT voltages and trip currents will be preset by the detector experts. The HV will be switched on by the shift crew by clicking on 'All HV' button on the GUI interface. If any of the bases fail to set their high voltage a non-expert will first retry clicking 'All HV'. If the problem persists the expert should be called.
Interlocks
Expert personnel
The individuals responsible for checking that the Hodoscope is ready to take data and setting its operating parameters are shown in following table. Problems with normal operation of the hodoscope 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.
| Name | Number | Date of qualification |
|---|---|---|
| Alexander Somov | (757) 269-5553 | |
| Franz Klein |
Tagger Microscope
The tagger hodoscope consists of an array of 100 x 5 scintillators which are installed on the tagger magnet focal plane and will be used to monitor the photon beam energy spectrum in the 'coherent peak' region.
Routine operation
The shift crew will be monitoring the detector performance parameters such as the counter rate per channel and detector occupancies
Control and monitoring of the system is accomplished using the Hall D graphical user interfaces (GUI) to EPICS [3] [4]. A description of how to bring up the GUI screens can be found in Section Slow Controls.
Voltage Settings and Control
Expert personnel
The individuals responsible for checking that the Hodoscope is ready to take data and setting its operating parameters are shown in following table. Problems with normal operation of the hodoscope 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.
| Name | Number | Date of qualification |
|---|---|---|
| Alexander Somov | (757) 269-5553 | |
| Richard Jones |
