Recent Log Entries

Instablity with 2L24-1

Log Number: 3533899Logbook(s): Entry Makers: staphanyBody: 

2L24-1 has had instablity issues and has arc faulted twice in the last hour. The previous shift had commented on this specific cavity as a potential issue. EES-RF on-call has been contacted and they are investigating the cavity.

FSD summary

Log Number: 3533892Logbook(s): Entry Makers: beneschBody: 

Why isn't there a "post elog" button on this screen?

BPMs at end of C line

Log Number: 3533886Logbook(s): Entry Makers: beneschBody: 

Since the CW viewer camera looking at the C dump has failed, I looked at the horizontal signals from the last three BPMs in the line, 3H07C (standard), 3H08 (big), 3H09. I think the latter two overstate position by a factor of two or so but will have to be run to determine that.

Figure 1 shows one week, periodicity in 3H08 (small) and 3H09 (large). Figure 2 shows one day. In figure 3 I added the other four SHMS magnets to figure 2. No periodicity at this coarse current scale.

Operator SIGN IN

Log Number: 3533871Logbook(s): Body:  ACCELERATOR OPERATOR SIGN IN FORM OPERATOR:    Echeverria
DATE:             02/18/2018
SHIFT:               Day

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Autolog restore

Log Number: 3533868Logbook(s): Tags: Body: restore Log Entrysaver ran from opsl04
Data from: /usr/opdata/burt/allsnap/02-17-18_18:26:01
Restored file: /tmp/02-18-18_08:09:28.snap

Autolog save

Log Number: 3533867Logbook(s): Tags: Body: save Log Entrysaver ran from opsl04

Saved: moser 02-18-18 08:09:22 {A:5 B:5 C:5 E:1050 A=CW B=CW C=CW 0R08=42.60 No dumps in. Autosave prior to restore.

Operator SIGN IN

Log Number: 3533866Logbook(s): Body:  ACCELERATOR OPERATOR SIGN IN FORM OPERATOR:    Anthony
DATE:             02/18/2018
SHIFT:               Day

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3C12A Trips Versus Overall CEBAF Current

Log Number: 3533855Logbook(s): Entry Makers: moserBody: 

Figure 1, top plot, shows total CEBAF current in blue (0R08), Hall A current in gold and Hall C in green, all on the same axis. The bottom plot in pink shows BLM 3C12A trips, green is NL RF, purple SL RF, and blue-gray Inj RF. A spike in pink without an associated spike in the other three indicates a 3C12A BLM beam trip alone, no accompanying RF cuplrit.

Around 0400, when only 52uA of beam were in the machine, we saw next to no 3C12A-exclusive beam trips. More than this, however, and the frequency of 3C12A-exclusive trips goes up dramatically, like between 0700 and 0800.

Autolog save

Log Number: 3533852Logbook(s): Tags: Body: save Log Entrysaver ran from opsl04

Saved: moser 02-18-18 07:48:30 {A:5 B:5 C:5 E:1050 A=CW B=CW C=CW 0R08=46.86 No dumps in.

RAT plots

Log Number: 3533850Logbook(s): Entry Makers: beneschBody: 

1L05-4 needs to be tuned or turned down. 2L12-3 and 2L14-4 seem to have regulation or phase issues. I don't know what to say about the other dozen.

RF fault rate

Log Number: 3533848Logbook(s): Entry Makers: beneschBody: 

Figures 1 and 2 show the fault rates I model. Ops has been turning down 2L25-1, the biggest offender. 2L20 is the lock zone; it's been pushed up. Figure 3 shows lem predictions including many small ODVH changes I just made to redistribute gradient upon next lem. Figure 4 shows that dropping the current used by lem from 600 uA to 540 uA, still 50% above the 360 uA we've been running in the linacs, would decrease trips one/hour. If we can get up to 410 uA in linac, 82*5, we'd still have ~30% margin for input Q, gradient calibration and tube power errors.


Log Number: 3533845Logbook(s): Body: 

Date : 02-18-18
Time : 07:24:28
Day : Sunday
Shift : Day

Crew Chief : Carlino
Program Deputy: Bickley
Team : X
Arm : Anthony
LERF Operator: NA
Operators : Anthony

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