[Esr-users] ESR status and recovery of Halls

[JLab]

Hi,

Dave Kashy and I just had a chat. I understand that Halls B and C are empty (mostly) while Hall A is trying to fill their magnets without much success - I think I saw LQ3 been put on cold return recently.  If the above statement is correct, could this this be due to a problem (or problems) like insulating vacuum (I think that I saw a question from Dave to the esr-users list asking about this but never saw an answer) or something else?

Thanks in advance for any help you guys can give me to understand what is going on - Javier

  
> On Mar 7, 2018, at 10:41 AM, Dave Kashy <kashy at jlab.org> wrote:
> 
> Hello All,
> The attached file shows the current status of all of the magnets in the ESR complex.
> It shows that we have not made significant progress in recovering from the trip two days ago.
> 
> It appears that shutting off Hall B completely was not enough to make the recovery simple.
> Yesterday we prioritized Hall A first and Hall C second in our meeting after the 08:00 meeting at MCC.
> Apparently this did not go so well.
> 
> Cryo started the transferline yesterday afternoon and we still have not made significant progress. 
> 
> This morning I met with the cryo group to discuss the possible causes.
> 1) we may additional loads - So each Hall A and C as well as cryo should check the VJ pressure or temperatures to look for additional heat loads.
> 2) We may have lost capacity of the ESR refrigerator so Cryo will check to see if flows and temperature ratios are normal
> 3) We may have magnets on the wrong type of return 
> 4) we may be trying to cool too much at the same time
> 
> 
> We decided that we must start to make progress and we will follow the priority guidance that was agreed to yesterday.
> 
> Recover A, then recover C then recover B
> 
> As such:
> 
> 1) Hall C should prioritize their system to take only 5 g/s until all Hall A magnets are full and stable
> 2) Cryo and Hall A should put all magnets on warm return and cool only a few at a time until those can be put on cold return while giving those on warm return just enough to keep them from warming significantly.
> 3) Hall B will wait until all other magnets are on cold return. 
> 4) After all the Halls are recovered, the 10,000 liter dewar at ESR will be topped off.
> 
> 
> If Hall C needs more or can take less flow please let me know.
> 
> Thanks
> Dave Kashy
> <Status of Halls 3_7_2018 10 am.pdf>_______________________________________________
> Esr-users mailing list
> Esr-users at jlab.org
> https://mailman.jlab.org/mailman/listinfo/esr-users