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Box Supplies Turned on and Cycled Once

5 hours 12 minutes ago
Log Number: 4474773Logbook(s): Tags: Body: 

The following box supplies were TURNED ON AND CYCLED ONCE by version 2-16 of the Box Supply Cycling Script:
ARC1A Ramp Rate = 7.400 A/s
ARC2A Ramp Rate = 6.712 A/s
ARC3A Ramp Rate = 2.329 A/s
ARC4A Ramp Rate = 10.144 A/s
ARC5A Ramp Rate = 9.307 A/s
ARC6A Ramp Rate = 9.326 A/s
ARC8A Ramp Rate = 11.455 A/s
ARC9A Ramp Rate = 8.864 A/s
ARCAA Ramp Rate = 11.756 A/s
RSEP8A Ramp Rate = 10.544 A/s
RSEP9A Ramp Rate = 4.774 A/s

alarms

Box Supplies Turned on and Cycled Once

5 hours 18 minutes ago
Log Number: 4474770Logbook(s): Tags: Body: 

The following box supplies were TURNED ON AND CYCLED ONCE by version 2-16 of the Box Supply Cycling Script:
ARC1A Ramp Rate = 7.400 A/s
ARC2A Ramp Rate = 6.712 A/s
ARC3A Ramp Rate = 9.294 A/s
ARC4A Ramp Rate = 10.144 A/s
ARC5A Ramp Rate = 9.307 A/s
ARC6A Ramp Rate = 9.326 A/s
ARC9A Ramp Rate = 9.356 A/s
ARCAA Ramp Rate = 11.756 A/s
RSEP8A Ramp Rate = 10.544 A/s
RSEP9A Ramp Rate = 4.865 A/s

alarms

gun rga analysis

5 hours 26 minutes ago
Log Number: 4474769Logbook(s): Entry Makers: marcyBody: 

checked RGA in prep chamber. All looks fine.
opened prep valve, minor changes to rga trace as expected. Noble gasses a touch higher than with the prep valve closed.
Neither chamber showed any hint of a leak with helium leak checking (just spraying, no bags).

Closed valve. RGA off for puck movement, can turn back on easily if needed after HV cable investigation

marcy

COMMENT ON Investigate and Troubleshoot YBBS06 ARC7 Shunt failure

5 hours 32 minutes ago
Log Number: 4474767Logbook(s): Body: 

DC power locked out the ARC7 box supply and removed one lead from the box supply, along with the in question YBBS06 shunt module from its slot. We then performed a resistance measurement of the magnet string, expecting to get a resistance reading of 3.2Ohms as done during the PM of the supply. We instead got a measurement of 2.014M Ohms, leading us to believe that the magnet is reading as an open. We then went into the tunnel and disconnected the magnet from the string to isolate it and reperform the measurement to further prove this theory.

kevino

ABIL tag #7509 on VBVAA03 has been removed

5 hours 39 minutes ago
Log Number: 4474765Logbook(s): Body: The following entry was removed from the Accelerator Bypassed-Interlocks Log (ABIL) Tag # 7509 Device: VBVAA03 Function: Beamline Valve Location: West Arc (W1) Purpose: Bypass Downstream Interlock to valve from VIPAA04 Removed By: <a href='mailto:moser@jla
webrun

Investigating the HVPS interlock inputs ...

6 hours 4 minutes ago
Log Number: 4474762Logbook(s): Entry Makers: gramescovertBody: 

There are 6 hardware interlocks than can fault the gun HVPS off via the HVPS interface chassis. Here is a summary of our checks...

1. PSS A chain - unable to check, a clue would be the INJ drops out of state

2. PSS B chain - unable to check, a clue would be the INJ drops out of state

3. SF6 pressure ">50 psi" - we have EPICS readback of signal + rolling average; occassionally there is an EPIC value caught <~50 psi with HVPS staying on, so we should recheck the trip limit; Figs 1-3 show random sampling; Fig. 4 shows I think a lower value ~45 around time of a gun trip, e.g.

grames

investigation of gun trip yesterday

7 hours 24 minutes ago
Log Number: 4474744Logbook(s): Entry Makers: marcyBody: 

Gun HV tripped last night. Checking ion pump behavior at the time.
Fig 1,2: The vacuum faults seem to have started first in the gun, then travelled downstream.

Figure 3 shows that, to the resolution of the epics time, the vacuum ok signal may have been the first to go bad triggering the valve to close then the gun voltage to drop.

marcy

VIP2I00 current voltage plot

7 hours 36 minutes ago
Log Number: 4474742Logbook(s): Entry Makers: marcyBody: 

Gun ion pump has known field emission. We haven't hipotted to avoid affecting the high voltage electrode. We've been running it at 3400V.

Figures 1 & 2: Measured current vs voltage today for voltages from 3 kV to 4.8 kV.

Field emission onset clearly turns on after 4 kV. Slight change in current during soak at 4.8 kV, and recovering to a slightly better value than prior to this once dropped to 3200V after changes.

During October when we calibrated voltage for ion pumps, we intentionally didn't vary VIP2I00V much.

marcy

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