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User name X. Zheng

Log entry time 00:08:38 on December 10,2004

Entry number 92685

Followups:

keyword=swing shift summary

16:20-16:45 rotate both HMS and SOS to 25 degrees, floor mark shows 24.95 for the SOS and 25.01 for the HMS (spokesperson said that's good enough);
16:45 start sweeping the hall; taking cosmic data, run #52187;
17:40 hall closed, we are ready for beam, but MCC is in the middle of some tests;
18:10 just when the MCC is about to send pulsed beam, we have a HMS dipole trip. see entries #92660 and #92661.
When we ramped up the magnet, it got stuck at B2->B3 (TV monitor shows B_true=B2 for 10 minutes ); we tried writing the B_set again, didn't work (get stuck at 0->B1 this time); we discharged the magnet, reboot the dipole PSU, reset the interlock and started all over again.
19:00 HMS dipole fully recovered, start commissioning!

th_HMS=25.01 degrees; th_SOS=24.95 degrees;
p_HMS=p_SOS=-1.3 GeV/c;

The following runs have 3% carbon target, 10uA with raster off:

#52188, junk because scintillator triggers were set to 1 instead of 3 for both spectrometers, and it had an end-of-run fail;

#52189 short run to check tracks/efficiencies, 10uA, 3% Carbon, raster off;
(was actually not so short)
we checked all histograms (tracking) and efficiencies with Ben and Dave, the conclusion is "everything is decent (besides some possible bad calibrations)";

#52190 long run for calibration (>400K on SOS and HMS);

Then we asked MCC to do a harp scan but was informed 5 minutes later that both harps are broken. We decided to skip the harp scan and proceed to beam position checks.

#52191 beam position check, sieve slits in for SOS and HMS, elreal for SOS and HMS; beam positions for this run were within +/-0.1mm of the expected values;
"beam_offset.kumac" tells us we need to shift the beam y-position by +0.75mm and the x-position is good.
#52192 beam position check, we have BPM y (both 00A and 00B) shifted by +0.75mm from their nominal positions; changed HMS to elclean since last run did not have enough electron statistics for the fitting; The kumac tells as the beam positions are okay in both x and y;

During run #52192 VMEC19 (the sos control) was rebooted (we need to logout from VMEC19 first, then log back in after the reboot)

#52193; LH2 target, triggers are HMS=3/4 Scin and SOS=elreal;

Start of run did not have the "sanity check" (pink sheet) for runs #52189-xxxxx, elog comments are wrong for these runs; rebooting CODA and VMEC18 did not help. Steve rebooted VMEC19.

21:10- changing configurations, prepare for LH2 production run.

This time, the HMS dipole was the first one which reached the set point (around 22:15) among all magnets.

We had some problem with HMS Q2 power supply, see entries #92681 and 92682;

Around 22:00-22:30, some harp experts went down to the hall (controlled access) to check the harps, but did not manage to fix them.

There was a minor problem with the BTA, see entry #92684;

24:00 at the end of shift, hall is in controlled access for the HMS Q2.
It tripped again (at 680A) after the power supply was reset from the Hall. The hope now is we will set it only to 620A (instead of 900A, the new number is from Paul), which should be enough for further running (the set current is around 500A for production).

Everything but the Q2 is ready for LH2 production.