[Dsg-mvt] MVT Gas System

[Brian Eng]

Flow was nice and flat with no issues at 200 sccm total for mix 2. I'm going to drop it to close to the minimum flows the MFC can do to see how it performs there, since last time we had issues at the lower flow values.

The spike in the C4H10 ~8 AM was when Bob was checking for liquid, so that is expected.



> On Feb 27, 2018, at 9:15 AM, Bob Miller <rmiller at jlab.org> wrote:
> 
> Hi Francesco and Guillaume.
> 
> We tested the mixing system last night for mix 2 and the mass flow controllers worked properly.
> 
> I would like to meet today to determine what other tests we need to qualify the mixing system so it can be used for the detectors instead of the premix bottles.
> 
> I am available most of the day.  Let me know when you can meet at the gas pad.
> 
> Thanks,
> 
> Bob
> 
> 
> On 2/23/2018 6:21 PM, mdefurne wrote:
>> Hi Bob,
>> 
>> I will not be at the lab from Monday to Thursday. So if you need anything during these days, please contact Francesco and Guillaume (in c.c.).
>> We went to see your setup and it is nice.
>> I agree we should do it when the accelerator is down. Is it on both days, monday and tuesday? We will turn off the gas flow  and the Hv the morning you want. Once you have plugged the bottles on the lines, we will flush a bit the new lines with the detectors bypassed. To do so, we plan to use about 20psi of premix gas. (it should be quick and enough for the lines only, GUillaume or Francesco will be there to do it).
>> 
>> It might seem a waste of premix gas but each time we used argon, we lost a micromegas tile. Today, three of them are not working anymore. It might just be a weird coincidence, but can you please check that argon is not contaminated by some other coumpound? This is why we will avoid to put anything than premix in lines and detectors until we open the dead one and figure out what happened.
>> 
>> Can you do the swapping of lines early in the morning? Monday or tuesday? So that we will have all the day to flush, bypass and then not bypass the detectors (valves are in the hall), and then flush the detectors with premix before turning them back on.
>> 
>> Have a good week end,
>> 
>> Kind regards,
>> 
>> Maxime
>> 
>> Le 23/02/2018 à 15:50, Bob Miller a écrit :
>>> All,
>>> 
>>> Morgan and I have the gas system ready to change over to the parallel mode where we can run premix to the detector while testing the mixing system.
>>> 
>>> I would like to install this system Monday or Tuesday, whenever the accelerator is down.  The detectors will be without gas for less than an hour.
>>> 
>>> As soon as the system is installed I would like to start the mixing system.  The low temperature is 41F on Tuesday morning, so that will be a good test.
>>> 
>>> Please prepare for the changeover and testing and let me know if there are any issues.
>>> 
>>> Thanks,
>>> 
>>> 
>> 
> 
> -- 
> Bob Miller
> Hall B Lead Engineer
> Jefferson Lab
> 757 269-7867
> 
> 

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