For Naming Czars:
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 or read back the measurements
Introduction
The Decarad system was developed at JLab - it consists of 10 radiation detecting heads (geiger-mueller (GM) tubes) that connect (signal & HV cables) to a central box. That box has a board inside for changing the HV level and reading out the GM tube signals. The center box is connected to a digi port server via DB9 at box to RJ50 at the digi, which is then connected to the outside world via ethernet. The software uses the epics tool Stream with an asyn connection to the digi to send commands to the center box to read and write. 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
In ~jnelson/sandbox/RadiationMonitoring/RadiationMonitoring-git/iocBoot/sioc-sys0-rm01 is the st.cmd file.
Below is a description of the PVs with proposed names
Proposed PV names:
| PV Name | Purpose | Save/restore | Archive |
|---|---|---|---|
| $(P):FIRM | read firmware number | ||
| $(P):HRTBT | read heartbeat | 60s | |
| $(P):HVSTAT | read status of high voltage | 60s | |
| $(P):TEMP | read temperature of chassis | 60s | |
| $(P):HVMON | high voltage reading (V) | 60s | |
| $(P):HVSETPT | high voltage setting (V) | yes | 60s |
| $(P):RACK:Position | String to hold a description of the rack position | yes | |
| $(P):nn:DoseRate | readback read back of dose from GM tube nn (01-10) in mR/hr (close enough, it saturates at xxx) | 60s | |
| $(P):nn:Position | 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.
Introduction
The Decarad system was developed at JLab - it consists of 10 radiation detecting heads (geiger-mueller (GM) tubes) that connect (signal & HV cables) to a central box. That box has a board inside for changing the HV level and reading out the GM tube signals. The center box is connected to a digi port server via DB9 at box to RJ50 at the digi, which is then connected to the outside world via ethernet. The software uses the epics tool Stream with an asyn connection to the digi to send commands to the center box to read and write. The software is part of the RadiationMonitoring slac epics package.
Cable Connection
Notes on cable connection (from email 8/12/21)
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