Aggregator

Log Number: 4543820Logbook(s): 

• ELOG
• LERFLOG

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

Date : 08-20-26
Time : 08:21:50
Day : Thursday
Shift : Day

Crew Chief : Blackshaw
Program Deputy: Park
Team : E
Arm : RadCon
Designated SSO: Janak
LERF Operator:
Operators : Thomas, Janak

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

Log Number: 4543819Logbook(s): 

• ELOG

Tags: 

• MCC8am

Body:  CEBAF SHIFT LOG Shift Summary

Start of shift: Recovered control of CC cell phone.

Log Number: 4543818Logbook(s): 

• ELOG
• LERFLOG

Body:  ACCELERATOR OPERATOR SIGN IN FORM OPERATOR:    Thomas
DATE:             08/20/2026
SHIFT:               Day

The operator has read the following:

• ELOG
• PD Shift Plan
• Radiation Surveys for PSS Segments in Controlled Access
• PSS Log

Log Number: 4543817Logbook(s): 

• ELOG
• LERFLOG

Body:  ACCELERATOR OPERATOR SIGN IN FORM OPERATOR:    Janak
DATE:             08/20/2026
SHIFT:               Day

The operator has read the following:

• ELOG
• PD Shift Plan
• Radiation Surveys for PSS Segments in Controlled Access
• PSS Log

Log Number: 4543814Logbook(s): 

• ELOG

Tags: 

• ShiftSummary

Body:  CEBAF SHIFT LOG Shift Summary

Start of shift: DecaRads moved into SL and HV checked.

Log Number: 4543813Logbook(s): 

• POLOG
• ELOG

Entry Makers: suleimanBody: 

We have VL beam from Hall C to FC1. We will be changing the VL settings in SCAM and also will try the User Mode.

Log Number: 4543812Logbook(s): 

• ELOG

Tags: 

• BeamAccounting

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

Log Number: 4543811Logbook(s): 

• ELOG

Tags: 

• BeamAccounting

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

Log Number: 4543810Logbook(s): 

• POLOG
• ELOG

Entry Makers: suleimanBody: 

Preparing for Helicity Decoder Board beam study.

With Tsettle = 100 us.

Log Number: 4543809Logbook(s): 

• ELOG

Entry Makers: jhowardBody: 

CW inhibited. Masking set to 1D.

Log Number: 4543807Logbook(s): 

• ELOG
• SRFLOG

Body: 

Field Emission Measurements

2L24 - https://logbooks.jlab.org/entry/4543806
2L23 - https://logbooks.jlab.org/entry/4543782
2L05 - https://logbooks.jlab.org/entry/4543776

2L03 - omitted due to HV body current faults
2L03 - https://logbooks.jlab.org/entry/4543775

Log Number: 4543806Logbook(s): 

• SRFLOG
• ELOG
• RFLOG

Entry Makers: dchriBody: 

Scroll to last image for Vacuum & CWWT overview plot

Cavity 1
Limited by max single DecaRad 01 head < 10,000
* I had not realized DecaRad 9 exceeded 10,000 mR/hr until cavity 2 testing concluded
Start GLOS = 2.69
Start GMES = 17.7
Ramp up GLOS = 3.44
Ramp up GMES = 22.3
DecaRad 01 = ~9360
DecaRad 09 = ~12,224 (highest)

Cavity 2
Limited by Admin Limit GMES < 24 MV/m
* I had not realized DecaRad 10 exceeded 10,000 mR/hr until the test began
* Levels reduced quickly once the test began, my hope is that the DecaRad did not become saturated
* DecaRad 10 < 10,000 once cavity 2 = 18.2 MV/m
Start GL

Log Number: 4543805Logbook(s): 

• ELOG

Entry Makers: dchri

Log Number: 4543804Logbook(s): 

• ELOG
• SLOG

Tags: 

• Autolog

Body: restorelib 3.0.1 Target restore date was 2026-08-20 02:28:06 The output from the myRestore execution was as follows: iocsoftw4spce systemEnum@2026-08-20 02:28 2(2) restored Execute: /usr/csite/certified/bin/ced2Epics -ced ced -A -i iocsoftw4spce (success) PVs modified: 0 PVs modified: 0 PVs modified: 0 PVs modified: 0 PVs modified: 0 PVs modified: 0 PVs modified: 0 Procedure return status: Success

Log Number: 4543803Logbook(s): 

• SRFLOG
• CLOG
• ELOG
• RFLOG

Entry Makers: dchriBody: 

Parasitically logging 2L24 Flow Meter data during Field Emission testing
I am not ramping heaters or adjusting JT valves
This is for data logging purposes only

Future ATLis:
https://tasklists.jlab.org/atlis/tasks/121136

Log Number: 4543786Logbook(s): 

• ELOG
• RFLOG
• SRFLOG

Entry Makers: dchriBody: 

Fig. 1 - 2L24 GOOD in Hot checkout
Fig. 2 - JAM south RF authorized

Fig. 3 - Field Emission ATLis status is 'OK'
ATLis 118604
https://tasklists.jlab.org/atlis/tasks/118604
DecaRad is verified connected to zone 2L24 - per ATLis comment

Fig. 4 - Rates with RF Off determined to be < 10 mR/hr
Fig. 5 - Vacuum nominal

Log Number: 4543783Logbook(s): 

• ELOG

Entry Makers: dchriBody: 

Log Number: 4543782Logbook(s): 

• ELOG

Entry Makers: eformanBody: 

Cavity 1: Started at 21 MV/m without quenching. Missed the "config decarad" step...aborted and started again at 21 MV/m.
Cavity 2: Quench >18.9.
Cavity 3: Started at 21 MV/m without quenching.
Cavity 4: Quench >12.7
Cavity 5: Started at 21 MV/m without quenching.
Cavity 6: Quenches above 20.6 MV/m.
Cavity 7: unable to raise gradient much above 20 despite increasing GLOS. Starting at 20 MV/m.
Cavity 8: Started at 24 MV/m

Log Number: 4543780Logbook(s): 

• ELOG
• LERFLOG

Body:  ACCELERATOR OPERATOR SIGN IN FORM OPERATOR:    Christian
DATE:             08/20/2026
SHIFT:               Owl

The operator has read the following:

• ELOG
• PD Shift Plan
• Radiation Surveys for PSS Segments in Controlled Access
• PSS Log

Log Number: 4543776Logbook(s): 

• ELOG

Entry Makers: eformanBody: 

Cavity 1: Started at 21 MV/m without quenching.
Cavity 2: Started at 21 MV/m without quenching.
Cavity 3: Cavity quenches above 19.7 MV/m (GLOS=3.75)
Cavity 4: Started at 21 MV/m without quenching. Field emission < 10 mRem/h
Cavity 5: Started at 21 MV/m without quenching.
Cavity 6: Started at 21 MV/m without quenching. Field emission < 10 mRem/h
Cavity 7: Started at 21 MV/m without quenching. Downstream vacuum valves closed. Restarted at 20.5 MV/m to completion
Cavity 8: Started at 21 MV/m without quenching.