[Esr-users] ESR Data and Test Scheduling

[Dave Kashy]

Hi All,
The measurement that David Schleeper performed gives us a data point.
During the testing:
* The ESTL was not providing a 4K boost to the ESR.
* All magnets cold, but no magnets powered
* No cold 15K targets in Halls A and C 
* No cryotarget load in Hall B

I estimate we have 7% spare capacity on the cold box. With this amount of spare capacity we seem to be able to keep all magnets full and stable. I calculate that we could convert that 7% to about 250W of 15K coolant for cryotargets. This would barely cover the static heat load w/o any beam heating. As we power the magnets the lead flows will increase. 

If all magnets are powered at full field the  total lead flow for all Halls will increase by ~2.1g/s, and it is not clear if the refrigeration load will increase also, but I suspect it may. 
For simplicity and robustness, I assume that we can't eat into the 7% spare capacity of the cold box.
Basing the analysis on the increased lead flow of 2.1g/s, 0.3g/s for Hall B cyrotarget, and Target loads of 700W @15K for Hall C and 100W at 15K for Hall A,  and 200 W of static heat load at 15K for the distribution system, I estimate that we will need an effective boost of 5.6g/s to be supplied by the CHL through ESTL. This does not take into account losses in that line. 

Hopefully CHL can provide this boost!

Thanks
Dave



----- Original Message -----
From: "David Schleeper" <davids at jlab.org>
To: "esr-users" <esr-users at jlab.org>
Sent: Tuesday, November 14, 2017 10:13:32 AM
Subject: [Esr-users] ESR Data and Test Scheduling

All,
With the existing loads on ESR and the plant at full discharge pressure, the dewar was filled ~0.23%/hr, or less than 1g/s of additional capacity.
The test was performed between 10pm 11/13 through 10am 11/14.


Regarding a full-load ESR test:
The CHL plants are stable and cryo would like to begin the process of scheduling a test that will include all expected loads for the Fall 2017 run.  This would require that all magnets be cold, energized, elevated lead flows, and a cold Hall C target with additional load to supplement the missing Hall A target loads.

Can this be scheduled for the end of this week or beginning of next?

-- 
Thank You,

David Schleeper, PE
Mechanical Engineer, Cryogenics Engineering
Thomas Jefferson National Accelerator Facility
757-269-6532
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