Difference between revisions of "Switching Modes"
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== Counting to Integrating == | == Counting to Integrating == | ||
== Integrating to Counting == | == Integrating to Counting == | ||
| + | # Preliminaries. to do long before switching | ||
| + | #* Make sure spectrometer DAQ works (might need reboots). Use the CODA guide if necessary. | ||
| + | #* Check cavities in integration mode and counting mode at high current. Run analysis macros. Do they work ? | ||
| + | #* Check with spot++ that rastered size is approx 4 x 3 mm (whatever is our present norm.) | ||
| + | #* Check the beam position ("centered" to within 0.3 mm, using the production criterea, see white board). | ||
| + | # Switching to Low-Current Counting Mode | ||
| + | #* Septum off | ||
| + | #* Take access. | ||
| + | #* Expert to do the switch of the detector signals to counting mode | ||
| + | #* Switch cavities to have amplifiers. Take out attenuator on BCM. Note: Cannot exceed 2 uA with amplifiers in place. | ||
| + | #* Set up cavities pre-gain and phase using established values. | ||
| + | #* Septum on | ||
| + | # Set Up Beam | ||
| + | #* Do the beam recovery procedure. | ||
| + | #* Establish 50 nA on Pb target (or whatever current on another target). Normally with laser attenuator = 65 and slit = 13, and then some adjustment to get rates low. | ||
| + | # Setting HV | ||
| + | #* Do NOT turn on scint or VDC HV yet ! Must establish rates first. | ||
| + | #* Info about detector HV | ||
| + | #* Turn on the HV for upper scint and S0 (if S0 is in place). | ||
| + | #* Adjust Quartz Detector HV for Counting mode. | ||
| + | #* VDC HV on (4 kV) if the T1/T5 rates are below 500 kHz. <b>If above 500 kHz do not turn on HV.</b> | ||
| + | # Take CODA run and analyze it as usual. | ||
Revision as of 11:05, 17 June 2019
In the process of editing and updating this page. Please contact Juliette Mammei crowder@jlab.org with questions or suggestions.
PREX Main<< HOW TOs
This page details the checklists for switching between counting and integrating modes. For reference, here are the instructions from PREX I
Counting to Integrating
Integrating to Counting
- Preliminaries. to do long before switching
- Make sure spectrometer DAQ works (might need reboots). Use the CODA guide if necessary.
- Check cavities in integration mode and counting mode at high current. Run analysis macros. Do they work ?
- Check with spot++ that rastered size is approx 4 x 3 mm (whatever is our present norm.)
- Check the beam position ("centered" to within 0.3 mm, using the production criterea, see white board).
- Switching to Low-Current Counting Mode
- Septum off
- Take access.
- Expert to do the switch of the detector signals to counting mode
- Switch cavities to have amplifiers. Take out attenuator on BCM. Note: Cannot exceed 2 uA with amplifiers in place.
- Set up cavities pre-gain and phase using established values.
- Septum on
- Set Up Beam
- Do the beam recovery procedure.
- Establish 50 nA on Pb target (or whatever current on another target). Normally with laser attenuator = 65 and slit = 13, and then some adjustment to get rates low.
- Setting HV
- Do NOT turn on scint or VDC HV yet ! Must establish rates first.
- Info about detector HV
- Turn on the HV for upper scint and S0 (if S0 is in place).
- Adjust Quartz Detector HV for Counting mode.
- VDC HV on (4 kV) if the T1/T5 rates are below 500 kHz. If above 500 kHz do not turn on HV.
- Take CODA run and analyze it as usual.
