[Esr-users] follow-up: Hall Cryo Status?

[Joe D. Wilson, Jr]

Hello,

During the South LINAC pumpdown to 2K then refilling of cryomodules, there
will be a disruption of CHL1 assistance to ESR for about 1.5 days. Based
upon the current schedule for the CHL1 transformer replacement efforts, the
South LINAC pumpdown is expected to start on Sunday morning 18Mar18. Before
the pumpdown, the plan is increase ESR dewar level to an abnormally high
level. Therefore, the temporary unavailability of the CHL1 assistance will
be replaced by the consummation of the stored refrigeration capacity by
allowing the ESR dewar level to deplete.

For planning the cooldown of 15K targets, the schedule is driven by CEBAF
beam restoration status and staffing of Halls A and C. Of course, the ESR
support of any 15K target should only occur after all 4.5K loads are full of
LHe and on cold return.

Thanks!

-----------------
Joe D. Wilson, Jr.
Cryogenic Operations Engineer

Jefferson Lab
www.jlab.org
757-269-7722
jwilson at jlab.org


-----Original Message-----
From: Esr-users [mailto:esr-users-bounces at jlab.org] On Behalf Of Dave Kashy
Sent: Tuesday, March 13, 2018 10:54 AM
To: Steve Suhring <suhring at jlab.org>
Cc: esr-users <esr-users at jlab.org>
Subject: Re: [Esr-users] Hall Cryo Status?

Hi Steve etal,

Below is the current plan that we should all baseline to. It was discussed
at the Physics Division Senior Staff meeting today. If anyone has issues
with this please let me know. 
Thanks 
Dave


Hall A,
All magnets full and ready to run

Hall B
Torus at 63K and Solenoid at 57K, buffer dewar empty

Hall C
All magnets full and on cold return.

Recent problems
Hall C had a 300K helium line leaking into the 4K circuit. This was
discovered and resolved.
Hall C had a valve fail on one magnet in the full open position. This was
discovered and manually resolved, and it the group is working on more
permanent solutions.
Hall B ESMTL (End Station Magnet TL = transfer line to the Hall B vacuum
spoiled upon warming and has been pumped back down.

Plan
Today: Perform an ESR/Halls A/C load and capacity test with Hall B off line
This afternoon: Start 4K supply to Hall B to cool the TL's
Wednesday and Thursday : Cool and Fill Hall B magnets and dewar
Friday and Saturday: - contingency
Sunday 3/18 : - shut off CHL flow to ESR and Pump the South Linac with CHL1
to 2K
Monday 3/19 : Cool the TL and recover Hall Magnets if needed
Tuesday/Wednesday 3/20-21 : Cool the cryotargets in Halls A/B/C to assure
all is ready for beam when it arrives

----- Original Message -----
From: "Steve Suhring" <suhring at jlab.org>
To: "kashy" <kashy at jlab.org>
Sent: Tuesday, March 13, 2018 9:03:31 AM
Subject: Hall Cryo Status?

Hi, Dave, 

Would you please provide simple statements on the cryo status for each Hall.
We are interested in getting this important step understood. If recovery
goes well, we'd like to be ready all around. 

Steve 

Something like: 

Hall A - Rt. arm magnets ready for operations. L arm Q2 warm due to a vacuum
problem. Anticipated cooldown Friday with full operational status by
Tuesday. Target cooldown remains. Needs to start 3 days before 1st beam into
the Hall. 

Hall B - etc.
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