[Hallb-engineering] [New Logentry] Follow-up Re: Follow-up Re: Follow-up Re: Hall B Status

kashy at jlab.org kashy at jlab.org
Wed Nov 11 07:00:01 EST 2020

Logentry Text:
Update this morning:
The Dewar is almost empty (5% liquid indicated so by Thursday it could be fully empty. We will know when the return temperature in the DBX gets above 275K (TD8522DR). Then we can move it to Level 1. It would be much better if we can do so without removing the U-tubes. If needed I can assist with the relocation. The dewar empty weight is ~255kg (prior to additional hardware and U-tubes added see attachment) so count on less than 1000 lbs total. 

After the dewar is moved and when pumps are available, we should check the vacuum and pump on the Dewar Utube vacuums.

The solenoid is at 44K and rising at 0.18K/hr
The torus is at 82K and rising at 0.06K/hr and flowing 1.6g/s of 80K helium

TL vacuum is still being pumped by cryo at ESR and Hall B techs in the Hall. Daily vacuum checks continuing. 
Yesterday the vacuum level was ~2.6E-3torr and Monday it was ~4E-3 torr

Torus vacuum is excellent 
CG8103 is 7.4E-5torr
Solenoid vacuum is even better 1.9E-6 torr


This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3857388
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