[Dsg-halla_gas] [EXTERNAL] Re: GEM gas distribution test setup

[Anuruddha Rathnayake]

Hello Marc and Chuck,

I was in communication with Kondo and he said that the usual operational
flow rate of a GEM module that we have will be 225 cc/min whereas the max
flow rate we will go would be 300 cc/min.  (The 75 cc/min flow rate is for
the "idling" state where we just flow Nitrogen to prevent any humidity
getting in to the cambers/modules)
 Therefore, the flow meters we use should give us the opportunity to go
slightly higher than 300 cc/min but probably it doesn't need to go as high
as 500 cc/min as the ones we have right now in the gas panel.
However, like Chuck said the main issue with the current flow meters have
been their high sensitivity to the turning knob making it difficult to set
the flow meters to small values like 75 cc/min.

I'd be happy to participate in a bluejeans meeting to discuss the
situation. However, I think Kondo will not be available as he's going to be
on vacation.

Best
Anu



On Mon, Jan 4, 2021 at 9:26 AM Marc Mcmullen <mcmullen at jlab.org> wrote:

> Hi Chuck,
>
> Thanks for the update. I will set up a bluejeans meeting this week so we
> can all discuss the situation concerning the panel. I have added this email
> thread to the mailing list (I added you before the holiday break), at this
> stage it is very important to that the DSG stay informed on the leak
> checking of this prototype to be able to make any changes necessary for the
> operational gas panels.
>
> Please let us know what the testing plans are as you proceed. This
> information will be informative to the group.
>
> Regards,
> Marc
>
>
>
>
> ------------------------------
> *From:* Chuck Long <mlong at jlab.org>
> *Sent:* Monday, January 4, 2021 9:07 AM
> *To:* Marc Mcmullen <mcmullen at jlab.org>
> *Cc:* Rathnayake, Anuruddha (adr4zs) <adr4zs at virginia.edu>
> *Subject:* Re: [Dsg-halla_gas] [EXTERNAL] Re: GEM gas distribution test
> setup
>
>  Hi Marc,
>
>  We have assembled an independent 4-way manifold in order to flow gas over
> the holiday, we are still using the panel flowmeters.
>
>  Gas flow set at 75 cc/min results in the flowmeters being barely on and
> at the bottom of the scale. We can find out from Anu what the typical flow
> will be and specify the flowmeters with one that puts the setting in the
> middle of the range. (maybe higher quality ones with glass vials?)
>
>  We will plan to leak check the rack this week, still seems to be leaking.
> We have a method of using air with a trace amount of hydrogen that the leak
> testers are sensitive to. (Cylinder is actually there and available from
> the GRINCH leak testing).
>
>
> -Chuck
>
>
>
> ------------------------------
> *From:* Dsg-halla_gas <dsg-halla_gas-bounces at jlab.org> on behalf of Marc
> Mcmullen <mcmullen at jlab.org>
> *Sent:* Wednesday, December 23, 2020 1:54 PM
> *To:* Anuruddha Rathnayake <adr4zs at virginia.edu>
> *Cc:* dsg-halla_gas at jlab.org <dsg-halla_gas at jlab.org>
> *Subject:* Re: [Dsg-halla_gas] [EXTERNAL] Re: GEM gas distribution test
> setup
>
> Hi Anu and Chuck,
>
> When we get back from break, I'll discuss changing out the flow meter
> valves for a more sensitive range (maybe 0 to 100 sccm) with George and see
> what he advises.
>
> During your leak checking, can you make note of what tubing was changed
> out. We are keeping a record of issues with the system. I have provided a
> spread sheet with the two connection for each length of tubing. If you
> could put a yes or no in the indicated cell it would help us understand
> where the leaks are.
>
> If there are other leaks please feel free to expand the chart. Also
> pictures of the new tubing would help.
>
>   Manifold to Flow Meter Panel Flow Meter Panel to Gas Flow Sensor chassis
> Ch1
> Ch2
> Ch3
> Ch4
> Ch5
> Ch6
> Ch7
> Ch8
> Regards,
> Marc
> ------------------------------
> *From:* Anuruddha Rathnayake <adr4zs at virginia.edu>
> *Sent:* Wednesday, December 23, 2020 12:35 PM
> *To:* Marc Mcmullen <mcmullen at jlab.org>
> *Cc:* dsg-halla_gas at jlab.org <dsg-halla_gas at jlab.org>
> *Subject:* [EXTERNAL] Re: [Dsg-halla_gas] GEM gas distribution test setup
>
> Hi Marc,
>
> There has been several leaks in the gas pannel and Chuck replaced all the
> Nylon tubing with Poly Ethylene tubging today morning. Now we are flushing
> the system and planning to connect the GEMs in the afternoon, if there are
> no more issues.
>
> Best
> Anu
>
> On Wed, 23 Dec 2020, 11:24 Marc Mcmullen, <mcmullen at jlab.org> wrote:
>
> Hi Kondo,
>
> I was just checking to see if there was an update on the test setup and if
> there are plans to flow gas during the holiday break.
>
> Regards,
> Marc
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