TITLE: 02/25 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 9mph Gusts, 6mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.19 μm/s 
QUICK SUMMARY:

More JAC work today

The annulus ion pump body for the BSC1 annulus system was replaced.  We then hooked up and started the turbo/aux. cart.  Pressure at the cart was dropping nicely as pumping commenced.  

There will be a pump cart running on the south side of the Y-arm beamtube, near the TCSY table, until the ion pump transition pressure.

S. Muusse, C. Compton, G. Vajente

We are still in the process of testing the CHETA electronics integration and have began fixing the optical setup on the ITMY Table to test the sensor in situ.
The optical system was realigned with the lenses, waveplate and polariser repositioned to ensure lower 4.65um intensity on the pickoff to prevent burning after the issues in post. All core optics for the 4.65um beam have been placed and we are in the process of adding the sensor paths and laser dumps. 

Electronics:
We tested all the laser diode and TEC controller ports on the chassis which were working. It is worth noting when connected to the Laser Enable control the diode will not turn on unless this is enabled and can be used to shut off the laser power.
The thermal power meter input was also working and power changes can be seen on ndscope
I've put in a table the status of all the CDS I/O we've tested so far:

Some notes are that:
PD_C is the thermal powermeter 
PD_A and PD_B are the PDs

We aim to installl the PD setup tomorrow and test its electronics. 

Medm
Adjacently, there was continued progress on the medm, a flipper control was installed using SQZT7 code, the slow PD was added using LSC_CUST_DCPD.adl and QPD using QPD.adl. Both will be tested in the coming days on the actual system and the rest of the controls added.

J. Freed (with help from Marc and Fil)

I tested the real wiring chain described in D2400111 from PD through the 3 variants of the TIA and it does follow exactly what is described in the link. There were 4 things of note that were found during this test. 

1. All the whitening filters were switched "on" inside the TIA, however our final design document states that only the QPDs need whitening. As such the SPD boards S2500647 and S2500645 whitening switches were set to bypass. I logged this change in the E-Traveler.

2. The D1700116 silicone circuit board for the FFD-200 causes shorts. The main issue is the GAP 5000 pinholes on the PD side of the board. If the PD is flush with the board those pins touch the case of the FFD. Since the GAP pins are also connected to the cathode and anode, this causes the circuit to short. This is simple enough to test without taking out any PDs from the case. If there is "no" resistance between the case (ground) pin and the anode/cathode pins on the DB9 connector coming from the PD, then it is shorting and the system should not be turned on. There are 2 options suggested to fix this, either put insolation between the GAP pins and the FFD case or cut the GAP pins connection to the FFD anode/cathode. For this specific test, the issue was bypassed by putting in a tissue between the FFD and the silicone board.

3. I tried to take transfer functions from all the PDs through the TIA, however the laser I used (the MIT ISC AM Laser) AM modulation was designed for 5 - 200 MHz, not the 4096Hz we are trying to use. As such, I suspect the harsh attenuation (~70dB at 4096Hz AOM_Attinuation.png) I measured was caused by the laser. So I decided it would be better to put off the transfer functions through the TIA until after SPI is built, then use our own laser AOM system to run the test. The laser was just left at DC and was used as the light source to see if signals on the PDs follow the correct wiring chain.

4. I used the laser to check that the signals on the PDs follow the expected wiring chain through the output of the TIA. Ex. Laser on Quadrent 1 of the QPD outputs a voltage on the expected pin on the output of the TIA. All pins were found to be correct.

Jason, Jennie, Betsy

After working for a bit to try to beam dump the second Septum refl beam dump which also is coming off the IMC septum window, we finally came to a solution.  It involved stealing one of the SPI D1800140-07 smallest beam dump panels and also putting it into the same mount as the first panel.  These 2 beams are pretty close to the main beam at this location, but with the beams otherwise hitting the internal metal of the output periscope we could not come up with anything better.  It took us quite a few small adjustments and many pictures to convince ourselves we are not clipping, but the attached picture is the best visual of the situation.  Commissioners agree that this is what we will live with.

TITLE: 02/25 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: N/A
SHIFT SUMMARY: Another productive day working towards closing out HAM1.
LOG:

Alignment into HAM2

Locked JAC with RF at 1W. IMC WFS was centered in IOT2L and IMC started working. As we steered JM3 MC2 TRANS responded as expected (i.e. JM3 PIT -> MC2 YAW and vice versa though there's a significant cross coupling). Sheila had to recenter the WFS once again at some point as the WFS started to get off-centered as we turned JM3, but as far as the WFSs were centered, things worked.

In the end, MC2 TRANS was centered reasonably well (right before the cursor in the attached), JM3 DAC output was O(1e7) while a 28 bit DAC's range is +-134e6.

Apparently we made the last step of JM3 PIT adjustment in the wrong direction at the time (we didn't notice because the WFS is very slow) and overshot. I steered it back later, now H1:SUS-JM3_M1_OPTICALIGN_P_OFFSET is -39 instead of -19 (second screen shot).

Anyway, this means that the alignment into HAM2 is good with more than a comfortable range left for JM3. No need to further refine.

One caveat is that the IM4 trans is totally off in PIT. But that's a downstream problem which we'll have to deal with later in HAM2. That should not prevent us from moving forward to close down the chamber.

The tasks listed below are described in different alogs.

JAC TRANS PD calibration

Last beam dump (alog 89249)

ALS beam path check

It seems that whitening gains of some corner station QPDs were somehow set to zero on Friday Feb/20 17:22 UTC (09:22 PST).

Not sure why this happened, this seems to be earlier than the failed effort to update h1imcasc model (alog 89208). ALS QPDs, end station QPDs and all WFS RFs are good. Was something done to Beckhoff that day? 

I first noticed this for MC2 trans yesterday because it was interfering with IMC locking and WFS triggering. I checked all QPDs and WFS today and found that the following channels were affected. I restored them all to the value right before it was set to zero. 

Tue Feb 24 10:14:58 2026 INFO: Fill completed in 14min 54secs

Bypass will expire:
Tue Feb 24 11:57:58 AM PST 2026
For channel(s):
    H0:FMC-CS_FIRE_PUMP_1
    H0:FMC-CS_FIRE_PUMP_2
 

TITLE: 02/24 Day Shift: 1530-0030 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: 0.03 μm/s
    Secondary useism: 0.29 μm/s 
QUICK SUMMARY: In the homestretch on HAM1 alignment activities and JAC commissioning, which continues on this rainy morning.

Workstations were updated and rebooted.  This was an OS packages update.  Conda packages were not updated.

02/23 S. Muusse, C. Compton, G. Vajente, S.Goswami, B. Wu 

The electronics chassis was brought into the lab today (thanks Phil and Dave) and we began testing the integration of the optomechanics with the CDS. An ethernet cable was run into the JOAT CHETA lab to connect to the server.  A variable power supply was brought into the lab to power the chassis at the required 24V along with a linear power supply required for the rotation stage and translation stages. 
The flipper I/O input and output had to be configured for Beckhoff communications using this guide.
The current status of our testing is as follows:
Working:

• Flipper
• PD
• Power meter

Not working:

• Rotation mount 

Untested:

• Translation stage

We have realised during this process that the flipper isn't powered by the SMA connectors and requires a seperate power source. This was not considered in the initial panel design and is not currently supplied by the chassis. There is a spare blank connector input/output slot which can be used. 

We have begun making the medm display for the CHETA system based on the current CO2 medm which shares many optomechanical systems. CHETA isn't currently on the TCS screen so to run the medm display currently the following command must be run to access the work in progress. 

medm -x -macro 'USERAPPS=/opt/rtcds/userapps/release/,SITE=LHO,site=lho,IFO=H1,ifo=h1,OPTIC=X,OPTICF=ITMX,name=AWCITMX,RT_MEDM=/opt/rtcds/lho/h1/medm' TCS_CHETA.adl 

To open the medm in a configurable format:
 medm TCS_CHETA.adl 
Alternatively to edit the code files:
code medm TCS_CHETA.adl 

Further alignment on the ITMY table was completed with almost all optics now mounted on the table. 

We installed JM1, balanced it and aligned it. A beam dump was placed behind it though we could not see the transmission with 1W input.

After this, JAC locked with RF without any problem though the input was wobbly when the purge was up.

We searched for unexpected ghost beams (also with 1W input) and didn't find any.

We uninstalled many (but not all) temporary dog clamps and irises.

We revisited the IMC alignment because it's been off in PIT since Thursday or Friday. We locked JAC using dither (because we wanted to turn down the purge air). We enabled the IMC WFS just for MC optics and steered JM3, but weren't able to center the MC2 trans. Steering JM3 just made the IMC transmission worse while making not much impact on the desired degree of freedon (JM3 PIT -> MC2 trans YAW, JAM3 YAW -> MC2 trans PIT).

Tomorrow, we'll revisit the IMC alignment. We'll also measure the power coming into JAC TRANS PD as well as the actual transmission of JAC while locking it with RF so we can use JAC trans PD as the measure of the power into HAM1.

Today, Gerardo replaced the annulus ion pump body for the GV6 annulus system.  He then handed off to me to hook up the turbo/aux. cart.  The pressure at the cart was ~3e-5 after 4 hours of pumping.  

There will be a pump cart running at GV6, at the Y-arm termination slab, until the ion pump transition pressure.