Aggregator

Log Number: 4496318Logbook(s): 

• ELOG
• LERFLOG

Body: 
THOMAS JEFFERSON NATIONAL ACCELERATOR FACILITY
ACCELERATOR OPERATIONS CREW CHIEF SIGN IN FORM

Date : 05-07-26
Time : 23:29:49
Day : Thursday
Shift : Owl

Crew Chief : Price
Program Deputy: Drury
Team : A
Arm : Samari
Designated SSO: Smith
LERF Operator:
Operators : Samari, Smith

This stamp certifies that the above Crew Chief has read/reviewed/received the following:

Log Number: 4496316Logbook(s): 

• BTLOG
• ELOG

Entry Makers: alexsBody: 

Based on the knowledge that the recent drift in the injector orbit begins at the 1I07 BPM, that narrows down the list of most likely suspects based on the injector beamline reference to the magnets MBH1I05, MQW1I05, MQW1I06, the Horizontal Wien, the Pre-buncher, and potentially the spin flipper solenoids. Looking at the available PVs, nothing stands out. No answers, but worth checking.

Log Number: 4496315Logbook(s): 

• ELOG

Entry Makers: kernsBody: 

Cavity 1 was most likely the klystron that dropped HV after it blew the klystron resistor that Alex replaced along with cavity three. Cavity 3 must have been bypassed on 05/02/26 because the operator logged it as a driveline problem when it was a klystron with only .5a output vice 1.2a normal. No KCCU/GMES on cavity 3 since 05/02/26. Alex replaced both cavity 1 and 3's 50 ohm resistors and cavity 3 should remain bypassed due to this low klystron KCCU when it was bypassed.

Log Number: 4496314Logbook(s): 

• ELOG
• RFLOG

Tags: 

• Autolog

Body: 

The following cavity histories have been updated:
2L11-3
Username: kerns
Date/Time: 05-07-26_23:22:31
RF Status: Bad
Tuner Status: Good
Comment: .5a KCCU on 05/02/26 when GMES wouldn't recover and it was bypassed. Needs klystron recovered to 1.2a KCCU. Resistor replaced 05/07/26 by Alex S.
Special Instructions:

Maintenance Tag: Component: Tube

Log Number: 4496313Logbook(s): 

• ELOG

Tags: 

• ShiftSummary

Body:  CEBAF SHIFT LOG Shift Summary

Start of shift: Beam to Halls B & D; Hall C down in CA for target ladder issues.

Log Number: 4496312Logbook(s): 

• ELOG

Tags: 

• BeamAccounting

Body:  Accelerator PHYSICS STUDIES RESTORE ACC DOWN OFF (SAM) Planned 8 0 0

Log Number: 4496311Logbook(s): 

• ELOG
• RFLOG

Tags: 

• Autolog

Body: 

The following cavity histories have been updated:
2L11-1
Username: kerns
Date/Time: 05-07-26_23:19:04
RF Status: Good
Tuner Status: Good
Comment: HV dropped in zone after klystron resistor blew apart. Alex S. replaced and recovered.
Special Instructions:

Maintenance Tag: Component: 50 Ohm Resistor

Log Number: 4496307Logbook(s): 

• ELOG

Body: Calibration ParametersHall:DTarget: 1.1x10-3 Al 100umPass: 5.5Note: Calibrated On:2026-May-02 07:48Calibrated By: msmithFile:D-2026-05-02_0748_1.1x10-3_Al_100um_Pass-5.5.hcdIon ChamberExisting Setpoing (rads/hr)New Setpoint (rads/hr)East Wa

Log Number: 4496306Logbook(s): 

• ELOG

Entry Makers: anthonyBody: 

Log Number: 4496303Logbook(s): 

• ELOG

Body: IDDescriptionPeriodCause 16879Title:
Lost Hall B Beam after shift in injector orbit

Summary:
When sending back after a trip, noticed that Hall B's current lock wasn't engaging because their BCMs weren't detecting current.

Log Number: 4496302Logbook(s): 

• ELOG

Entry Makers: ywangBody: 

2157-2207
The injector front-end orbit drifted, which affected beam delivery, especially Hall B beam.
Correected the drift and all is well.

Log Number: 4496301Logbook(s): 

• HBLOG
• ELOG

Entry Makers: shrinerBody: 

Log Number: 4496299Logbook(s): 

• ELOG

Body: IDDescriptionPeriodCause 16880Title:
Inj. Adjustment.

Summary:
Injector drifted to the point Hall B CW was not making it out of the INJ.

Log Number: 4496298Logbook(s): 

• ELOG

Body: IDDescriptionPeriodCause 16880Title:
Inj. Adjustment.

Summary:
Injector drifted to the point Hall B CW was not making it out of the INJ.

Log Number: 4496297Logbook(s): 

• ELOG

Tags: 

• Autolog

Body: saver ran from opsl06

Saved: ywang 05-07-26 22:11:27 {A:i B:5 C:2 E:345 A=BS B=CW C=Tune D=CW 0R08=3.06 C dump(s) in.

Log Number: 4496296Logbook(s): 

• BTLOG
• ELOG

Entry Makers: alexsBody: 

Searching through the BPM values just before losing B beam, it looks like the orbit in the injector suddenly shifted starting at the 1I07 horizontal BPM shifting ~1 mm to the left, and everything downstream went with it. The Injector SME is on-site and investigating now.

Log Number: 4496295Logbook(s): 

• ELOG

Body: IDDescriptionPeriodCause 16879Title:
Lost Hall B Beam after shift in injector orbit

Summary:
When sending back after a trip, noticed that Hall B's current lock wasn't engaging because their BCMs weren't detecting current.

Log Number: 4496293Logbook(s): 

• ELOG

Tags: 

• Autolog

Body: System UN-Masking for: BeamLossMonitor
User: lrichard
Areas: All

BeamLossMonitor Devices:
ILM0I07
ILM0L01A
ILM0L01B
ILM0L02
ILM2D00A
ILM2D00B
ILM0L04A
ILM0L04B
ILM0L05
ILM0L06A
ILM0L08
ILM0R01
ILM4D00
ILM0R03
ILM0R04
ILM0R06
ILM0R08
ILM0R09
ILM1L01
ILM1L02
ILM6R08
ILM3S00
ILM7S00
ILM9S00
ILM5S10
ILM5E03
ILM7S01
ILM9A01
ILM3E02
ILM5A01
ILM1A04
ILM1A06
ILM1A09
ILM5A10
ILM1A16
ILM1A19
ILM3R10
ILM9R07
ILM1R09
ILM2L03
ILM5R10
ILM5R05
ILM2L01
ILM2T09
IL

Log Number: 4496291Logbook(s): 

• ELOG

Tags: 

• Autolog

Body: System Masking for: BeamLossMonitor
User: lrichard
Areas: All

BeamLossMonitor Devices:
ILM0I07
ILM0L01A
ILM0L01B
ILM0L02
ILM2D00A
ILM2D00B
ILM0L04A
ILM0L04B
ILM0L05
ILM0L06A
ILM0L08
ILM0R01
ILM4D00
ILM0R03
ILM0R04
ILM0R06
ILM0R08
ILM0R09
ILM1L01
ILM1L02
ILM6R08
ILM3S00
ILM7S00
ILM9S00
ILM5S10
ILM5E03
ILM7S01
ILM9A01
ILM3E02
ILM5A01
ILM1A04
ILM1A06
ILM1A09
ILM5A10
ILM1A16
ILM1A19
ILM3R10
ILM9R07
ILM1R09
ILM2L03
ILM5R10
ILM5R05
ILM2L01
ILM2T09
ILM8T

Log Number: 4496281Logbook(s): 

• ELOG

Body: 

Replaced load resistors for cavities 1 and 3. Cavity 3 was already bypassed for RF drive issues, so pulled the jumper for it to reduce the risk of another unnecessary drop. Will leave the PTW on issue until end of day tomorrow just in case there are any emergent issues with the cavity 1 replacement resistor.