[Halla_running] [New Logentry] RC daily update (Saturday day/swing shift shift workers needed!)

[shujie at jlab.org]

Logentry Text:
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We had some smooth running on Friday and early Saturday ( ABU>70%) except a slightly large span on beam y position (https://logbooks.jlab.org/entry/3627120) and a ROC31 crash (https://logbooks.jlab.org/entry/3627199). On Friday JP (target expert on call) warned us that the target heat leak is getting worse every time we change target. He opened JT valve to  calm the ladder temperature down.  We didn't plan to move target at all over the weekend. But on the Saturday afternoon the right arm Q2 tripped. We had to run target home to allow Heidi and Jack work on it ( https://logbooks.jlab.org/entry/3627944 ). After that we moved target back to Tritium but the ladder temperature wouldn't go below 50K despite we increased the 15k cryo flow. So we took some data with the higher than usual but stable ladder temperature. Late in the swing shift Meekins went to the hall and found that the 15k transfer line failed. He decided to warm up the target and replace it.  (https://logbooks.jlab.org/entr
 y/3628012)

Hall:
In restrict access since Sunday to allow multiple people work on the repair.

Plan:
Cool down the target on Tuesday. This run period is extended from Wednesday to Sunday morning. Extended shift schedule was opened and get filled quickly ( many thanks!). Now we only need a Saturday day SL and swing SL, TO. 



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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/3628449
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