This is a late entry from last Friday.  We have removed the relay tube between HAM5 and HAM7 and replaced it with the adapter/viewport assembly on the HAM5 side.  The assembly is being pumped down independently by a small turbo/aux cart.  The GV should not be opened until the pressure in the viewport assembly is approximately the same as the corner pressure and the aux cart is valved out.

Ryan S, Rahul, Fil, Camilla 

This morning when checking what our ranges are on ZM4 and ZM5 PSAMS, we noticed that ZM5 wasn't working, plot,  strain gauge was reading ~ -1 to -1.3V in the whole 0V to 200V range. The issue looks like electronics and started Saturday afternoon when no one was working on it, plot attached. 

Ryan and I went to the chassis and checked the calibration box Daniel modifed was securely attached 91106, holding it tight to the chassis made no difference. We then pulled it and took it to Fil. 

TITLE: 07/20 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 3mph Gusts, 1mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.09 μm/s 
QUICK SUMMARY:

VAC Status: HAM1 pressure is currently at 8.45xe-7 Torr. and everywhere else around  1e-6 torr. 

I'm resetting the tripped ETMY HEPI & ISI  watchdogs that tripped in the last earthquake.

LVEA Is still Laser Hazard.

Trello schedule: 
Unlock all HEPI (see where VAC is going to need access)
DRMI Locking work!
PSL incursion to swap SPI shutter cable to perm one
Early Mornings - Cleanroom Maint work (needs lift) Randy
Leak checking all over the LVEA
Remove NEG pumps off Output Tube, LVEA?

Starting at 23:47 Sun-19Jul2026-PDT the ETMY test mass was rung up by an earthquake. Both SEI and SUS had both tripped at 00:02 Mon-20Jul2026-PDT. The ETMY HWWD counted down to 7 mins before resetting.

At 06:45 I untripped the SWWDs. The user model WDs remain tripped.

(Travis, Gerardo)

I chose the wrong viewport to start leak checking. 

Travis and I decided to use the XBM turbo station to leak check the new joints affected by the vent.  At the turbo station we substituted the helium leak detector in place of the nominal local scroll pump at the the exhaust of the XBM turbo, and then the Vertex and YBM turbo stations were valved-out of the main vacuum envelope.  Once the setup was established the leak detector reported a background of 1.0x10-10 Torr*l/sec.  I started spraying the first viewport, but I picked the new CHETA viewport.  Anyways, in short, I manage to saturate the leak detector, why? Because the CHETA vp is an O-ring viewport, and helium can permeate thru O-rings with ease, and I was spraying for regular CF joints, like if I was using a garden hose, in time the leak detector signal went up to 2.4x10-09 Torr*l/s, we stopped leak checking and valved in the other two turbos, and valved out the leak detector from the XBM turbo station via an O-ring valve, and restored its scroll pumping.  We'll try again Monday.

The corner isi sensor correction was turned on at 20:45 PT and will be running overnight in order to evaluate the possible improvements from the new HAM3 CPS. It had been left off to avoid noise reinjection from people working in the LVEA, but should be ok to have on during the weekend. Having the sensor correction ON for some time will allow to compare the ISI spectra with last year's, before the CPS change, in the same control state.

A quick check of the HAM2-3 (X, Y, Z) was done before / after the change to verify there is no issues (fig 1 - blue is before, red is after). The IMC stayed locked during this transition (control signal in fig 2 - blue is before, red is after).

Something is really wrong but we haven't figured out what exactly that is.

As of now, IMC_LOCK guardian locks IMC automatically if we wait long enough. The problem as of now is that the FSS is hit hard when H1:IMC-REFL_SERVO_COMBOOST is enabled IF the residual low frequency component of the IMC lock error signal  (H1:IMC-I_OUT_DQ) is big. In such a case FSS is unlocked and sometimes FSS autolocker goes into a loop of state 2 to state 3 to state 2. (The problem was made worse by the JAC guardian's behavior to unlock itself whenever FSS is unlocked, and that the JAC auto locker somehow kept trying to lock to the fringe at a very low PZT voltage and immediately unlocked, but these JAC problems were solved now. See alog 91105.)

However, IMC doesn't lock with nominal gains. I had to considerably reduce MC2 gain: Overall gain was reduced by a factor of 0.035 (H1:SUS-MC2_M3_ISCINF_L_GAIN=0.035), and the M3 gain was further reduced by a factor of 0.2 (H1:SUS-MC2_M3_DRIVEALIGN_L2L_GAIN=0.2). M2 and M1 gain are nominal. (Probably the overall gain should be set upstream like   H1:IMC-MCL_GAIN or H1:IMC-L_GAIN, but that's not what I did.)

Once IMC is fully locked, IMC stayed locked unless we started changing gains too much and/or injecting huge signal. Also, fully locked, I can flip the COMBOOST switch OFF and back ON quickly without killing FSS.

We measured the IMC crossovers but they were all very wrong. 

On Monday we should measure the overll OLTF on the floor to see if the fast path is still good. If it is we can focus on diagnozing the MC2 actuation, otherwise there could be a deeper problem.

PSAMS ZM5 strain gauge calibration:

Replaced the 82.5K resistor between pins 12 and 11 with a 61.9K one. 

Readback now ranges from -0.8V to +8.5V for PZT voltages 0 and 200V, respectively.

Keita, Elenna, Ryan,

Keita noticed that the JAC was sometimes finding a resonance at a very low voltage offset on the PZT actuator and running out of range when it tried to lock near as it was near the bottom rail of the PZT voltage. See the photo for an example, the scan just keeps rampign from 0, finding a resonance but not lockign successfully.

They changed this from 0V to 50V to avoid this problem. This is channel H1:JAC-PZT_DRIVER_SCAN_START for reference and is set by the guardian to the correct value of 50V in the 'SCANNING' state.

Jennie Wright, Khanh Vu

Below is a summary of the work we did on the JAC IOT1 table today, July 17th.

For JAC commissioning, we had planned to install a higher-attenuation ND filter on the JAC Trigger PD and turn down the power on the JAC REFL A PD. Our concern was that the power in the Trigger PD path might be too high and cross its trigger threshold. We came in to measure the beam power with and without the ND filter.

With ND filter: 12.51 mW between the ND filter and beam splitter; 2.1 mW in front of the REFL PD.
Without ND filter: 0.39 V on TrPD; 6 mW on REFL PD.

The power on REFL PD is not too high even without the ND filter and with JAC unlocked, so we decided to check our calculations.

Using existing data from when the JAC was locked vs. unlocked (attached below), we found a visibility of 65.9/922.2 = 0.07. This is higher than my previous calculation of 0.056, but since the numbers are so small, the fluctuation is acceptable. A higher visibility also allows a larger error margin, which is preferable for ensuring the power does not get too high during a run.

The calculated power on REFL PD at 65 W locked is 13 mW, and the calculated voltage on TrPD is 0.89 V. These numbers look good even without ND filters, so we don't need to change or install them.

As part of WP 13402 we did some daqd restarts today.  These were to pull in changes to the EDC to reflect the reconfiguration of the DAQD system and the additional channels generated by the safety system update.

In addition on review of the system wiring, we switched the location of two fibers on h1daqdc1 to keep it consistent with the fiber layout on h1daqdc0.   The fibers where the link to the front end data stream, and the live data stream to the NDS2 systems.

This was the first time that we had done a channel list change since updating the daqd config.  This found an error in our puppet configuration.  Normally when the data concentrator machine starts up it grabs the channel list from the main copy, and stores a copy of the channel list that all the other daqd in its leg refer to.  This keeps a stable copy of the channel list that only updates on restarts.  During the puppet reconfiguration, this addition to the startup sequence got lost and was not applied on h1daqdc1.  It didn't show itself until we did the restarts with a new channel list, at this point the frame writers where disagreeing on the channel list.  This has been fixed in our puppet config now.

After some minor cleanups, a fiber re-arrangement, and several restarts and debugging the daqd system is running, the edc is connected to all its channels.

Sheila, Camilla, Ryan S, Cory (Fellow), Rahul

Given below is the summary of beam alignment work we performed in HAM7 today.

After locking the SQZ beam and the OPO we first checked the alignment on the OPO - it looked good and there was no clipping anywhere. Then we checked the beam on ZM4 and ZM5. Camilla measured the incoming beam on ZM4 to be 5.5inches approximately and it looked well centered on the iris in front of it.

On ZM5 the beam was very high on the optic (we had to remove the face baffle to be able to see the beam on the PSAMS mirror). At first we tried using  ZM4 sliders to center the beam on ZM5, but ran out of range. Hence, we mechanically adjusted ZM4 in pitch (using the pitch adjuster) to bring the beam down on ZM5 and center it (Camilla took pictures for reference). 

The beam from ZM5 to the beam divertor was off in both pitch (beam too low) and yaw (too wide as well, almost missing). We first adjusted ZM5 in yaw (mechanically) to center it on the beam divertor - we also had to push it slightly (less than 3mm) side ways for this purpose. With Yaw looking good on the beam divertor, we tried using sliders for Pitch but quickly ran out of range. I then used the mechanical pitch adjuster, but even that was not enough (ran out of range here too). Hence, I added 50grams of weight to the rear side of ZM5 intermediate mass to pitch it up (by 0.5inch) on the beam divertor. This worked and the beam looked good both in pitch and yaw on the beam divertor. 

Finally Ryan S checked the beam on the periscope and the two irises on SQZT7 table. It was off in Yaw - so I applied a negative yaw (clockwise rotation) on ZM5 mechanically (again the sliders were not enough for this big move) using dog clamps and round end screws (for better yaw control). While I rotated ZM5 in Yaw, Ryan S held an IR card on the periscope (SQZT7 table) and Camilla kept an eye on the beam, telling us when to stop. Once we were satisfied in both pitch/yaw on the periscope, Ryan S looked at the two iris in SQZT7, and he was happy with it as well.

I dogged down ZM5 and also re-attached the face baffle before closing the curtains on HAM7 chamber. Camilla started using sliders to fine tune the alignment.

Tomorrow morning I will take health checks on both ZM4 and ZM5 suspensions. 

Per FRS 38164, the unused viewport located at A1F1 and A2F1 on HAM7 have been removed and blanked off.  These viewports are being moved to HAM3, so serial number, etc. will be recorded in a separate aLog.

Camilla Sheila