Aggregator
Crew Chief Timesheet Summary: 16 May 2026 SWING
Scan of harp_2H00A
"xD resumes 25nA"
Scan of harp_2H00A
"xD BNR for orientation change"
Scan of harp_2H00A
Scan of harp_2H00A
OOC Update
Quick update, read previous elogs for details.
Tuned via viewers.
First, we looked at 2C24 for scraping by slow steering at a few upstream correctors vertically and horizontally. Did the same at 2C21 viewer. No scraping nearby the original beam locations.
Crew chief recalled an earlier elog entry by Benesch referring to 2C03 quad having some leverage.
Started there and adjusted. Viewer at 2C21 didn't change much, though it blooms more and it hard to see. On 2C24, it lessened the horizontal tail.
Scan of harp_2H00A
QuickPic - Hall B Tagger degaussed and turned off
TAGGERB has been disabled in alarm handler
Scan of harp_tagger
Scan of harp_2c21
B beam live optics tuning on 2C21/24 viewers
Figure 1: C beam 7 uA bleedthrough, slit 16.4. The rest of tuning was done with only B beam (C and D off).
Iterated 2C03 and 2C23 quads to squeeze down beam size and cut off (visible) tails. Figure 7 and 8 are beam spots after cycling quads twice to ensure reproducibility. Beam visibly appears sufficiently round and converging from 2C21 to 2C24
Status Update
After a visit from Hall B Experiment Spokesperson expressing displeasure with current status, we've contacted Optics on call who has arrived onsite, secondary also came onsite for something else but the timing was impeccable.
Spoke to Optics SME, tried a few things:
1. Hall B removed the empty target cavity and the Midstream counts went away. Harp scans were taken and signs of scraping or tail is still there; so this is not a Halo issue. This is a beam shape issue.
2. Tried adding compression using 0L04 gangphase; no joy.
3.
QuickPic - Tagger powered on for live 2C24 viewer tuning
Tried 0L04 compression
Adjusted 0L04 gangphase by +4.0 degrees and had Hall B scan at 2C21.
Fig. 1 Shows my initial increment value of 0.1. (Later I changed it to 0.5)
Fig. 2 Shows original 0L04 settings
Fig. 3 Shows +4 degrees in 0L04 gangphase.
Fig. 4 Shows 2C21 harp scan with +4 degrees in 0L04 gangphase (no change from before).
Fig. 5 Shows 0L04 back to it's original settings.










