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COMPLETED 1L06 Heat load / Qo assessment

7 hours 24 minutes ago
Log Number: 4471773Logbook(s): Body: 

With JT valve & Cryo Heater Parameters set to those found in this procedure...
JT seemed to settle between 75% and 82%
JT with all RF cavities on settled between 78% and 80%

Cavity 5 stood out the most to me
Turn cav 5 off --> JT reduced ~ 2 to 4 % from all cavities on baseline
Turn cav 5 on --> JT increased ~2 to 4% from all cavities on baseline

More details with plot images & timestamps
https://logbooks.jlab.org/entry/4471763

With a HIGH baseline heat (200W), JT settles at a high setpoint, and thus takes less steps when maintaining helium.
The JT already has +/- ~ 1% movement with no chan

dchri

QE Measurement

7 hours 43 minutes ago
Log Number: 4471769Logbook(s): Body: Spot Location: (13250,19250), Charge: 1.998958

Laser Wavelength Atten Setting Laser Power Current HV PS Current QE PV Updated? Update Time/Reason Not Updated (nm) (W) (uA) </
kprice

Tuned, adjusted attenuator for 1L14-5

8 hours 14 minutes ago
Log Number: 4471765Logbook(s): Entry Makers: kpriceBody: 

GASK was high enough to cause SOSing. Tried open-loop tuning but ultimately had to open up the attenuator considerably (9.3 -> 2) to get GASK into a reasonable range. This cavity is really touchy when it comes to tuner movement - no change for a long time, then huge swings with very few steps.

kprice

OLT 1L06-4

11 hours 2 minutes ago
Log Number: 4471762Logbook(s): Entry Makers: dchriBody: 

Cavity had trouble coming up. OLT and letting it rest at 11.5 MV/m (drive high 12 MV/m)

dchri

OLT 1L06-5

11 hours 15 minutes ago
Log Number: 4471761Logbook(s): Entry Makers: dchriBody: 

Spikes in VIP1L0640 while bringing up cavity 5

Initially, Forward power was way too high. open loop tune, walked cavity up...

Going to let it sit at 7.5 MV/m

Anything above that causes a Vac fault

dchri

Operator SIGN IN

13 hours 51 minutes ago
Log Number: 4471760Logbook(s): Body:  ACCELERATOR OPERATOR SIGN IN FORM OPERATOR:    Christian
DATE:             02/17/2026
SHIFT:               Owl

The operator has read the following:
  • ELOG
  • PD Shift Plan
  • Radiation Surveys for PSS Segments in Controlled Access
  • PSS Log
dchri

COMMENT ON Startup of Two Additional Central Chilled Water System Chillers and Associated Primary and Secondary Pumps and Final Commissioning

14 hours 19 minutes ago
Log Number: 4471758Logbook(s): Body: 

Subcontractor is tentatively scheduled to loaded revised Central Chiller System software on Thursday 2-19-26 which will require Building 60 chillers, primary pumps, secondary pumps, cooling tower pumps, and cooling tower fans to be switched to manual operation. The existing remote differential pressure sensor located at Test Lab TLA Air Handling Unit 58-AHU-2 will need to be replaced and revised control software loaded. Loading the revised control software will require a brief shutdown of 58-AHU-2 which conditions the TLA R&D Chem Room.

jonesc

CREW CHIEF SIGN IN

15 hours 3 minutes ago
Log Number: 4471757Logbook(s): Body: 
THOMAS JEFFERSON NATIONAL ACCELERATOR FACILITY
ACCELERATOR OPERATIONS CREW CHIEF SIGN IN FORM

Date : 02-17-26
Time : 23:15:06
Day : Tuesday
Shift : Owl

Crew Chief : Price
Program Deputy: Buttles
Team : D
Designated SSO: Christian
LERF Operator:
Operators : Christian

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

Shift Information

Shift Day
CEBAF Program
MCC Crew Chief Blackshaw
MCC Operators Janak
Program Deputy Buttles
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