[clas_members] [EXTERNAL] RC Meeting and Summary for May 19th

[Lamiaa El Fassi]

Dear Colleagues,

This is a friendly reminder of our RC meeting this morning at CH Room 200C
and online in ZOOM; please see its connection info below.

The RC summary of the last 48 hours is enclosed below and can be accessed
at https://logbooks.jlab.org/entry/4377310 .

Best,

Lamiaa

RC Summary for May 17th - 19th <https://logbooks.jlab.org/entry/4377310 >
This is the RC Summary of the last 48 hours starting from the day shift of
Sat., May 17th, 2025

===========================* Daily RC Meeting Info *
===========================
Time: *11:30 AM EDT *
Location: *CH Room 200C and online via ZOOM *
ZOOM URL link <https://urldefense.proofpoint.com/v2/url?u=https-3A__jlab-2Dorg.zoomgov.com_j_1605705819-23success&d=DwIFaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=nhU86tu_xVxwkH2JyhlcQb1jyw6CUjquEwQhqpV3cJI&m=ejhZoDRLQWFG2LIziaDoBpBHtdH23VjxfTnv3xHUaqpT9nfWHgnXWzktsuv_IePR&s=DKf_r7uL4h2n5OGIx19efeB72Sh8DDpTkWvEuuUU7JM&e= >
(including passcode)
ZOOM meeting ID: *160 570 5819 *
===========================* May 17th Day Shift
<https://logbooks.jlab.org/entry/4377085 > *=============================
- The shift started with beam off based on the high-level decision to
suspend Hall-B beam operation due to the inability to keep our beam halos
happy due to the 80s beam oscillations, beamline scrapping, bleedthrough,
etc., as discussed in yesterday's RC summary
<https://logbooks.jlab.org/entry/4377255 >. Then, based on the 9 AM RC/PD
meeting's discussion, they decided to dedicate ~ 3 hours of beam tuning to
debug the Hall B issue by altering the vertical separator. Expected update
by noon EDT.

- Around 11:30 a.m., the crew chief called, stating the work was done, and
they were ready to start tuning low beam current to our FCup starting from
5 nA while watching FSDs. Starting at 5 nA was OK, but as soon as ramping
up the beam current to 50 nA, FSDs started tripping again and drawing high
rates, even when a beam is OFF due to a bleedthrough or scrapping something
upstream our beamline; see, e.g., this BEAM Overview Scalers at 50 nA
<https://logbooks.jlab.org/entry/4377217 >. As a result, the MCC decided to
cease tuning us beam and focus on other halls, at least until tomorrow's
PD/RC meeting. For that reason, all shifts have been canceled until the
Sunday day shift, whose shift takers are on standby!

==================* May 17th Swing Shift thru May 20th Owl Shift *
=================
- * All shifts are canceled! *

===========================* May 20th Day Shift *
=============================
- * A shift is on standby *since MCC plans to investigate our beam quality
issues, as announced today, Monday, May 19th, in their morning meetings!

===========================* Game Plan *===========================
- Updated Short Term Schedule
<https://wiki.jlab.org/clas12-run/index.php/Run_Group_L#tab=Short_Term_Schedule >

=============================* BTA *=============================
- ABU: 342.8 → 342.8 / (68.5 × 24) = 20.85%, * as of 05/16 due to beam
delivery issues! *
- Day 43 of 137 scheduled: 43 / 137 = 31.4 %
- BANU: none; no beam!

========================* Outstanding Major Tasks * ========================
- 80s beam oscillations, beamline scrapping, and bleedthrough!
- Faraday Cup vacuum remains elevated — to be addressed after run ends

=============================* Run Summary *=============================
- None; no beam!
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