about 20 min ago

H1 ISI ETMX trips again on actuators.

Got up to:
Level 2 isolation on both stages,
TCrappy blends on both stages,
ST1-ST2 sensor correction on

Went back to what I was doing, then ~5 minutes later, both ST1 and ST2 actuators trip.

What is the difference between when visiting commissioners design all of these improvements vs. when they trip? Day time vs. night time? Weekends vs. During the week? There's something systematically wrong with our commissioning process.

For the records. GPS time 1078083583. Tripped on Actuators. 

Level 2 isolation on both stages, no ST1-ST2 sensor correction on. Had been running on "Start" blends on both stages for quite some time, T240s were pleasantly green. Tried moving ST1 from "Start" to "TCrappy", tripped halfway through on actuators. First glitch in captured screen show is start of switching third spike killed it.

Since glitch appears much larger in horizontal, we'll try switching vertical first (Z, RX, RY), then horizontal (X, Y, RZ).

• Longitudinal: +0.5 mm
  • Tolerance: ±3.0 mm
• Lateral: +0.2 mm
  • Tolerance: ±1.0 mm
• Vertical: -0.1 mm
  • Tolerance: ±1.0 mm
• Yaw: 20 µrad CW
  • Target: 0 µrad
  • Tolerance: ±50 µrad

All is within spec, we are ready to move forward with HEPI actuator attachment; IAS will take another look afterwards to ensure we are still within spec.

Has been for about 20 min.

Per work permit 4479.

Sometime between leaving the cartridge test stand and yesterday inside of BSC10, the optics in the suspension got really dirty.  The barrels of the ETM test mass, ERM optic, and PUM have accumulated alot of particulate.  I wiped these clean just prior to welding in Jan and recall them looking much better than they do in the pictures below when they were hanging on the test stand.  So, between the last bit of cartridge work, the cartridge flight and the in-chamber work over the last week lots of particulate has swirled around the in-vac hardware (about a 2 week duration).  Here's the sequence of cleaning in case Calum wants to know:

On test stand, just prior to flight:

- I wiped and vacuumed SUS, bagged both SUS and TMS

- Hugh wiped all of the ISI above, then bagged ISI

Cartridge flight Feb 24th

~2 days after in-chamber I wiped entire floor and viewport surfaces of BSC10 chamber, I did NOT inspect optics

- cabling, TMS payloading, SEI float/balance

- yesterday, I see this gross particulate accumulation, some on the suspension structure too, harder to see since it's metal surfaces though

- I wipe the entire floor of chamber again

More cleaning to follow, obviously.

Started ETMY TF at gps 1077929299 on opsws0 for M0 and R0 in undamped and damped config. The measurement will be running for ~15 hours. This is to assess for rubbing after installation in chamber, and before tomorrow's alignment check.