[Hallc_running] [New Logentry] RC daily update

billlee at jlab.org billlee at jlab.org
Thu Aug 20 12:00:13 EDT 2020

Logentry Text:
Dear Collaborators,

Around 6pm yesterday afternoon, the NMR result on the target polarization show only 7%. A decision was made to run 6 hours of Reference cell production filled with He3. Thanks to Tods (with escorted access by MCC operator) was able to refile the reference cell with He3. During reference cell data taking the polarized target was being pumped.

At 2:30am, NMR result shown 29.8% polarization, and we decided to performed positron running on the SHMS. The SHMS polarity change (From -7.5 to +7.5) was complicated by current and mas flow interlocks.  The polarity change and ramping procedure was  completed with expert instruction (slow ramping method) and at 6:30. We took 1.5 hour positron run at SHMS = 11 degrees, P=+7.5 GeV.

The moller started as planned at 8:30 this morning, we requested one IHWP change during the moller measurement. However the latest news shown the Moller IOC (froze) and  need to be rebooted. Escorted access is required (Moller solenoid is now being ramped down). In parallel Bill H is attempting reverse polarity back to -7.5 to perform a NMR measurement. We will post the result very soon.

The target change will proceed as planned starting tomorrow 8 am lasting appropriately 3 days. The news target is expected to be back around Sunday Swing. Appropriate plan has been made .


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/3831567
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