J. Kissel, for D. Barker

Here is be the timing sequence (assuming the excitation of the suspension is continuous) implemented on H1 SUS/SEI ETMY IOP Software Watchdog (SWWD) and Hardware Watchdog (HWWD):

1. T=0, SUS detects an excitation of the suspension, starts its IOP SWWD WD countdown timer. HWWD also starts its countdown.

2. T=5 mins, the SUS WD countdown expires. The IPC to the SEI IOP SWWD goes to zero.
2.1 the SEI SWWD WD countdown timer starts
2.2 the SUS SWWD DK countdown timer starts

3.0 T=9mins, the ISI and HEPI models see only one minute left on the SEI IOP WD countdown, nicely zero out the DAC drives in preparation for DACKILL

4.0 T=10mins, the SEI IOP SWWD times out and DAC KILLS the ISI and HEPI DACS

5.0 T=20mins, the SUS IOP SWWD times out and DAC KILLS the SUS DACS. Also the HWWD powers down the ISI coil driver chassis and HEPI valve driver chassis

6.0 T=40mins the HWWD opens the relay contacts disabling the SUS coil drive signals.

Yesterday, with Mark's help I took videos of a walk round at EndX and EndY at LHO. The purpose was to record where various pumps, instruments etc are located to aid Systems in updating drawings. In particular we noted the positions of the trillium seismometers, taking measurements from fixed references. Videos, stills etc are saved on the DCC at T1400438.

Summary of the problem:

We have been struggling for several months with what we believe are direct (magnetic) couplings between the BSC-ISI actuators and seismometers . We have tried to measure and subtract the main coupling (Z to RZ). We have obtained substantial improvement in the T240 response, but no improvement in the optics low frequency motion as seen by the optical levers. Our conclusion at his point are, that we need to identify and subtract the couplings in other directions and/or there is noise injection somewhere between Stage 1 and the bottom mass of the quad.

Low frequency couplings analysis:

The two BSC-ISI units locked at LHO (ITMX, ITMY) give us a great opportunity to study the low frequency direct coupling from the actuators to the sensors. This document compares transfer functions of the BSC-ISI when the two stages are floating (unlocked/free) and  when the two stages are locked. We use two series of measurements performed on ITMY. The goal is to figure out whether the low frequency features in the inertial sensors response are due to motion (translation or tilt coupling) or due to direct pickup (magnetic fields).

Comments are embedded in the document.

The last slide carries the most important information.

No change anticipated to corner station laser hazard configuration today.

Matt H/Corey - Continuing ISS prep work

HAM3 - ongoing work with 532 nm fiber-coupled laser (Kiwamu/Sheila)

ITMX - alignment looks ok...need to check Arnaud's TFs from last night

Jason may need to review ITMX alignment

EX - TCS will transition to laser hazard, finish populating the HWS section of ISCTEX and do some alignment work with the ALS laser

Richard M investigating heat concerns with racks at end stations

Calum presentation on contamination control

       -MEMO regarding particle counters T1400024

       -Tree showing where to start with contamination control knowledge E1400029

[Sheila, Kiwamu]

We spent some time trying to align the simulated beam to the POP QPD sled today in HAM3. Since we got confused by ghost beams for a while, we were not able to finish aligning the beam.

We are aiming to get this whole mission done by the end of tomorrow.

We have set up a fiber-coupled green laser to simulate the red POP path. The output coupler of the fiber is set up on the in-chamber table with a clean base plate underneath it to prevent from contamination. The laser is collimated with a small collimator directly attached on the coupler. The laser beam is then steered by a temporary mirror such that we can perform a fine alignment by touching this mirror. We let the beam go through the scraper baffle and PR2 and all the way to the POP sled. However, in the course of the alignment, we think we got confused by a combination of a ghost beam and extremely dim main beam reflected by a BS in front of QPD_A. This actually had been known to be an issue (see alog 5774 and alog 5924), but we simply forgot this issue and went ahead without paying much attention. We then noticed, at some point, that we had screwed up the alignment by ourself. Sad.

In the tomorrow morning, we will resume the alignment work. Once it is done, we are going to move on to installation of the 90/10 BS and subsequent alignment recovery.

I just noticed (or just realized) that the Laser Room lights were on with the Laser Area Enclosure in "Science Mode," i.e. HEPA fans off and HVAC units switched OFF.

Although the lights in the room are LEDs, this is way too much heat load for the room when the HVAC units are off.

In the future, we should always check the video displays in the control room to ensure that the lights are off when we are in "Science Mode" for the Laser Area Enclosure.

Particle counts taken in HAM 2 during the day

Start of the morning work day reading taken in cleanroom:

0.3um........90 counts

0.5um.....40 counts

0.7um...20 counts

1.0 um....10 counts

Remainder...zero

Start of morning work day reading taken in chamber

0.3um.....20 counts

Remainder...zero

End of morning session reading taken in chamber

0.3um...180 counts

0.5um.....100 counts

0.7um....70 counts

1.0um....40 counts

2.0um.....40 counts

5.0 um...20 counts

Start of afternoon session, readings taken in cleanroom

Everything....zero counts

Start of afternoon session reading taken in chamber

0.3um....50 counts

0.5um....10 counts

End of afternoon session, reading taken in chamber

0.3um...70 counts

0.5um....50 counts

0.7um.....30 counts

1.0um...20 counts

Remainder.....zero

J. Kissel, D. Barker

In the spirit of LHO aLOG 9204, we've shaken H1 SUS ETMY using H1 HPI ETMY in order to test the sanity of thresholds set for both the IOP Software WD (IOP SWWD) and the newly implemented Hardware Watchdog (HWWD). These values are currently set at 110 [mV] output of the RMS circuit (which is identical both in the HWWD and IOP SWWD), which via this test, is determined to be roughly 10 +/- 5 [um] or [urad] peak-to-peak (as reported by ISI ST1 CPS, SUS M0 OSEMs, and SUS L3 OPLEVs). See attached overall time-series of the entire test, whose timeline is below. This mount of motion has been blessed by my spider sense of "Wow, that's a *lot* of motion; it's giving me the willies. We should cut off SEI excitation after 10-20 minutes of this." Note that, gauging by the motion of speed-dials, this amount of motion is still *less* than what occurs if, say, Betsy and Travis are mechanically aligning the suspension, so it's still a conservative threshold (because, of course, when at vacuum, and the chamber is fully isolated no such motion should ever occur).

Things we've learned:
- The IOP SWWD and HWWD now have their threshold set to 110 [mV], equivalent to ~10 [um] or ~10 [urad] of motion, pk to pk.
- The RMS output of both the IOP SWWD and HWWD track each other quite well -- as long as the signal is above ~30 [mV] or ~3 [um] or [urad] -- only the IOP SWWD readout is more the accurate below these amplitudes.
- Driving a 0.1-to-10-[Hz]-band-limited, white noise excitation at he maximum amplitude of HEPI's DACs does not trip the IOP or HW WDs. One must focus the power at a given frequency to really ring up the RMS.
- The calibration from counts to mV for the HWWD RMS OUT channel -- for now, randomly stuck in H1:IOP-ISC_EY_MADC0_EPICS_CH30 -- is roughly 0.1 [mV/ct].

Why the HWWD user interface is icky, but it'll still work:
- (As mentioned above) the RMS output of the HWWD does not report any change unless there is a significant amount of motion already present.
- The RMS output of the HWWD is choppy -- performing a sample and hold on the RMS value, and jumps around by 10s of [ct], or a few [mV] under constant excitations.
- The three HWWD analog trip flag channels -- for now, stuck in H1:IOP-ISC_EY_MADC0_EPICS_CH27 through 29 -- are railed when not tripped, and low when tripped.
- The after entering value in the requested RMS voltage trip point, H1:SUS-ETMY_HWWD_RMS_REQ, the readback, H1:SUS-ETMY_HWWD_RMS_RD only returns a value *close* to what's been requested. Similarly the two readbacks, H1:SUS-ETMY_HWWD_TIME_RD and H1:SUS-ETMY_HWWD_TTF_SEI for the time until trip report values only *close* to the requested value, H1:SUS-ETMY_HWWD_TIME_REQ.

There's still a significant amount of hardware that needs installing / replacing before we can hook the HWWD up to actually kill ISI coil drivers and HEPI valve drivers, but we will now propogate these thresholds and this infrastructure to the remaining QUAD suspensions over the next week or so. We will also perform a similar test on HAM chambers once they become available, to set those SUS' IOP SWWD thresholds (or at least confirm that they should be the same.)

 Detailed Time Line
GPS Time    Amplitude    Notes
1087849965    100000     WN; Y, RX, RZ
1087850060    200000     WN; Y, RX, RZ
1087850199    250000     WN; Y, RX, RZ
1087850287    400000     WN; Y, RX, RZ
1087850326       HPI USER WD Trip
1087850348          start over
1087850484    300000     WN; Y, RX, RZ
1087850742    300000     WN RZ RX; 100000 ct 0.5 [Hz] Sine Y                       
1087850995     done
1087854054    Full bandwidth HEPI TF

where WN = white noise excitation, between 0.1 and 10 [Hz], and 0.5 [Hz] Sine = single frequency sine wave at 0.5 [Hz].

As in the original test, I turned OFF all control on the ISI and SUS, and turned OFF isolation control on HEPI. When ramping up the test, I began driving HEPI without turning off the ISI -- the ISI isolation loops survived through 20000 [ct] of HEPI excitation.