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The radiation read back PV names are RADM:SYS0:x00:GAMMA_DOSE_RATE, where x is 1 or 2.
About the software
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The decarads are talked to through a DB9 connector connected to a Digi Portserver. The software uses EPICS ASYN and Stream Device to send the commands to set the HV, read back the measurements, etc. The software is part of the RadiationMonitoring slac epics package. The source code can be reached from a development machine (currently afs): cd $EPICS_IOC_TOP/RadiationMonitoring. The database code is in RadiationMonitoringApp/Db/common in three files: decaradChannel.template, decaradCommon.template, decarad.substitutions. The startup files are in iocBoot/sioc-sys0-rm01. The ioc status & control can be seen from LCLShome, SC gun, Network/Global under RadiationMonitoring sioc-sys0-rm01. The IP addresses are ts-sys0-nw01 and -nw02.
The database files have the PVs divided by per-head and per-system
We have two decarad systems. Each consists of 10 small Geiger-Mueller (GM) radiation detecting heads that are connected (signal & high voltage (HV)) to a central unit which has some brains to control the HV level and read out the measured dose rates. The plan is to mount these to two frames that will be positioned near cryomodules during RF commissioning to measure radiation. The systems will be moved every day or two as we commission all cavities. The systems were designed and built at JLab and used for many years. The decarads are talked to through a DB9 connector connected to a Digi Portserver. The software uses EPICS ASYN and Stream Device to send the commands to set the HV, read back the measurements, etc. The software is part of the RadiationMonitoring slac epics package. The proposed software is currently in afs:
~jnelson/sandbox/RadiationMonitoring/RadiationMonitoring-git/RadiationMonitoringApp/Db/common:
decaradChannel.template - records associated with each GM head
decaradCommon.template - records associated with the system
decarad.substitutions - substitution file for templates
The proposed ioc name is sioc-sys0-rm01.
In ~jnelson/sandbox/RadiationMonitoring/RadiationMonitoring-git/iocBoot/sioc-sys0-rm01 is the st.cmd file.
For archiving I made:
- records associated with the system
decarad.substitutions - substitution file for templates
For archiving:
...sandbox...RadiationMonitoringApp/srcArchive/common/decaradChannel.tpl-arch and decaradCommon.tpl-arch
...sandbox...RadiationMonitoringApp/srcArchive/lcls/sioc-sys0-rm01.sub-arch
Below is a description of the PVs with proposed names
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PV names:
| PV Name | Purpose | Save/restore | Archive |
|---|---|---|---|
| $(P):DEV_FW | read firmware number | ||
| $(P):HEARTBEAT | read heartbeat | 10s | |
| $(P):HVSTATUS | read status of high voltage | 10s | |
| $(P):CHAS_TEMP | read temperature of chassis | 10s | |
| $(P):HVMON | high voltage reading (V) | 10s | |
| $(P):HVCTRL | high voltage on/off 0 = on, 1 =off | yes | 10s |
| $(P):LOCATION | String to hold a description of the rack position | yes | |
| $(P):nn:GAMMA_DOSE_RATE | read back of dose from GM tube nn (01-10) in mR/hr (close enough, saturation curve starts to roll over about 10R/hr - see plot below) | 1s | |
| $(P):nn:POSN | string to hold a description of the position of GM tube number nn | yes | |
| $(P):SEQ | sequence to readout the PVs at 1 Hz. The SEQ record has a delay of 0.06 seconds between sending 1 to each PV's PROC field so commands don't collide in the cable |
There are two sets of decarads (10 heads + central unit) so the PVs listed above are doubled and differentiated by $(P).
Suggested $(P) = RADM:SYS0:100 or RADM:SYS0:200 for the two systems.< End section for Naming Czars - thank you for your help! >
How to set the HV
From: Larry King <king@jlab.org>
Sent: Wednesday, March 9, 2022 12:49
To: Nelson, Janice L. <jnelson@slac.stanford.edu>
Subject: RE: decarad hv settings
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