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Started ramping up the gun and set the new HV limit at 140 kV
After swapping the damaged Gun HVPS cable with a spare one this morning, we started ramping up the gun and set the new HV limit at 140 kV.
Plan for today's ramp rate at different HV ranges are as follows:
0-25 kV (at 5 kV/min rate), wait few minutes
0-50 kV (at 5 kV/min rate), wait few minutes
0-75 kV (at 2.5 kV/min rate), wait few minutes
0-100 kV (at 2.5 kV/min rate), wait few minutes
0-125 kV (at 1 kV/min rate), wait few minutes
0-140 kV (at 1 kV/min rate), wait few minutes
Hand it over to ops to soak the gun at 140 kV for the weekend.
Injector in Power Permit
Please do not ramp/apply voltage to the gun
We're recovering from a failure of the gun HVPS cable to vacuum chamber ceramic. Repair and restore working is going well so far. For the remainder of the weekend we'll be only be applying lower voltage to the gun. Hopefully our weekend tests will help us have a path forward by Monday day shift.
In the meantime...
...please do not initiate any gun HV ramps and work with CIS for any changes to the gun high voltage controls. We'll leave further instructions, but wanted to get this message in the logbook.
Damaged gun high voltage cable staged for rad survey
The damaged high voltage cable from HVPS to gun (350 to R30) has been tagged and staged for rad survey at the bottom of the INJ stairwell. Not urgent, when convenient.
A photo of the damaged R30 plug end with the securing fixture flange removed is shown in Fig. 1.
COMMENT ON Jumper gun HVPS interlocks (gun valve/15 deg dipole/SF6 interlocks) for HV testing
Applied jumper to J6 input on gun HVPS interface chassis. ABIL #9449 is made.
For details of adding jumper see - https://logbooks.jlab.org/entry/4474959
Gun HVPS J6 jumper added to clear global interlock
Applied a jumper to the gun HVPS J6 input to clear the global/vac interlock.
Fig. 1 shows the rear of the 1U chassis in IN01B02 with jumper installed and usual interlock cable disconnected in-hand.
Fig. 2 shows the face of the 1U chassis prior to applying the jumper (Global Interlock = faulted = unlit)
Fig. 3 shows the same now with J6 jumper added (Global Interlock = okay = lit)
ABIL Tag #9449 added to HVPS MPS interlock (valve, dipole, SF6).
APPROVED Jumper gun HVPS interlocks (gun valve/15 deg dipole/SF6 interlocks) for HV testing
QuickPic - Lock Processes Operational (Energy, Orbit, Generic)
QuickPic - 2L10-4 OLT
All magnets in eDT are set to 345 MeV/linac design values
For all magnets up to xBCD dumplettes.
I went through and double checked that all Box supplies and Quads are set to design values. There were a handful of quads set to zero but have now been set (made sure we were good to go in SRM first).
The only magnets not set to design are:
MXM3S03 shunt (see linked Ops PR). Design is setting current over limit.
MARC7A shunts as the box supply is turned off due to YBBS06 issues.
MXM3S03 shunt out of range at design setpoint
Noticed this shunt 3.67% off design in eDT.
When setting to design setpoint, the control system is requesting 9.057 Amps but shunt throws a current limited alarm and limited to 5.266 Amps.
Put setpoint back where it was to not stress/damage shunt module.
Not sure if eDT is incorrect or the current limiting setpoint is incorrect.










