[Dsg-rtpc] RTPC Gas Controls Meeting Minutes

Thu Feb 14 13:21:24 EST 2019

Item #2 is 100% NEW. The current gas supply system was designed to privide a constant gas flow and a constant differential pressure with respect to ambient or atmospheric pressure. It was not designed to maintain a pressure setpoint. The gas exhaust bubbler maintains a differential pressure according to the oil level set. The absolute pressure in the detector will vary with atmospheric pressure.

What is the pressure setpoint and normal pressure operating range you now require? Depending on your requirements, it may require a PID loop to operate an exhaust valve to control pressure. If a PID loop is required, it will add an additional cost for the valve, valve controller, and valve power supply.

Cheers,

George

--
George Jacobs
Jefferson Lab (TJNAF)
STE 12
12000 Jefferson Ave.
Newport News, VA 23606
(office) 757-269-7021
(cell)   757-876-0480
(email) jacobsg at jlab.org

________________________________
From: Dsg-rtpc <dsg-rtpc-bounces at jlab.org> on behalf of Narbe Kalantarians <narbe at jlab.org>
Sent: Thursday, February 14, 2019 11:12 AM
To: Marc Mcmullen
Cc: dsg-rtpc at jlab.org
Subject: Re: [Dsg-rtpc] RTPC Gas Controls Meeting Minutes

Guess it got collapsed somehow.

I know that item 1 is already going to be take care of.

1) Obviously we need to log all of the monitored quantities (temperatures, pressures and gas flows) in the CLAS12 data stream.

2) There should be a feedback loop that regulates the gas flow to keep the pressure inside the RTPC at a fixed value (set by the operator from an EPICS screen)

3) There should be programmable alarm levels (both hi and lo) on all pressures and the gas flow, including the supply pressure (e.g. when the bottle gets close to being empty)

4) Drift gas should ONLY be shut off if there is a sudden increase in gas flow indicating a rupture somewhere

5) In the case of 4) or if the gas flow / pressure sink BELOW an adjustable level, the HV should be shut down (not the gas flow). This is to prevent sparks if ambient air can enter due to a rupture or due to empty supply bottles

Narbe Kalantarians, Ph. D.
Assistant Professor of Physics
Virginia Union University, Dept. of Natural Sciences
+1-804-257-5617 (VUU)
+1-757-269-5566 (JLab)

On Feb 14, 2019, at 11:10 AM, Marc Mcmullen <mcmullen at jlab.org<mailto:mcmullen at jlab.org>> wrote:

Hi Narbe,

There was no attachment or information on your email.

Marc
________________________________
From: Narbe Kalantarians
Sent: Thursday, February 14, 2019 11:06 AM
To: Marc Mcmullen
Cc: dsg-rtpc at jlab.org<mailto:dsg-rtpc at jlab.org>
Subject: Fwd: RTPC Gas Controls Meeting Minutes

Hi Marc,

Please see below for input for alarms/interlocks re: drift gas system. The ODU group will give (further) input on alarm need for the drift monitoring system.

Also; if Nathan Baltzell isn’t no this mailing list, can you add him?

Thank you.

Narbe Kalantarians, Ph. D.
Assistant Professor of Physics
Virginia Union University, Dept. of Natural Sciences
+1-804-257-5617 (VUU)
+1-757-269-5566 (JLab)

Begin forwarded message:

From: "Kuhn, Sebastian E." <skuhn at odu.edu<mailto:skuhn at odu.edu>>
Subject: Re: RTPC Gas Controls Meeting Minutes
Date: February 13, 2019 at 2:00:41 PM EST
To: Narbe Kalantarians <narbe at jlab.org<mailto:narbe at jlab.org>>
Cc: "christy at jlab.org<mailto:christy at jlab.org>" <christy at jlab.org<mailto:christy at jlab.org>>, "Hattawy, Mohammad" <mhattawy at odu.edu<mailto:mhattawy at odu.edu>>, Carlos Ayerbe Gayoso <gayoso at jlab.org<mailto:gayoso at jlab.org>>, "Bueltmann, Stephen L." <SBueltma at odu.edu<mailto:SBueltma at odu.edu>>

Here are my 5 cents on these questions:

1) Obviously we need to log all of the monitored quantities (temperatures, pressures and gas flows) in the CLAS12 data stream.

2) There should be a feedback loop that regulates the gas flow to keep the pressure inside the RTPC at a fixed value (set by the operator from an EPICS screen)

3) There should be programmable alarm levels (both hi and lo) on all pressures and the gas flow, including the supply pressure (e.g. when the bottle gets close to being empty)

4) Drift gas should ONLY be shut off if there is a sudden increase in gas flow indicating a rupture somewhere

5) In the case of 4) or if the gas flow / pressure sink BELOW an adjustable level, the HV should be shut down (not the gas flow). This is to prevent sparks if ambient air can enter due to a rupture or due to empty supply bottles

Anything else anyone can think of? - Sebastian

On Feb 13, 2019, at 1:06 PM, Narbe Kalantarians <narbe at jlab.org<mailto:narbe at jlab.org>> wrote:

Are there any particular details needed for the drift gas system, re: HV/LV failures, other than to shut off the drift gas system?

From: Dsg-rtpc <dsg-rtpc-bounces at jlab.org<mailto:dsg-rtpc-bounces at jlab.org>> on behalf of Marc Mcmullen <mcmullen at jlab.org<mailto:mcmullen at jlab.org>>
Sent: Thursday, February 7, 2019 4:58 PM
To: dsg-rtpc at jlab.org<mailto:dsg-rtpc at jlab.org>; Mohammad Hattawy
Subject: [Dsg-rtpc] RTPC Gas Controls Meeting Minutes

Hi,

Attached are the minutes/notes from the meeting with the RTPC/BONuS12 group. The information provided during the meeting has been added to the agenda is in italics.

Thanks
Marc
<RTPC Gas Controls Meeting_020719.docx>_______________________________________________
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