Updated SRC output filters

Jennie W, Jim W,

 

We swapped out the cdsOutput blocks SPI-H23_LO_SRC_CLKMON, SPI-H23_LO_SRC_SINMON, SPI-H23_LO_SRC_COSMON for cdsfilt clocks so we can put in some gains and readout fast channels in medm at this point in the model.

I made these changes in the HJK library part for SPI.

These filters banks are switched on with a gain of 1 but I still need to update the medm screen with the new channels and filter banks.

I also added the channels SPI-H23_LO_SRC_CLK_IN1, SPI-H23_LO_SRC_SIN_IN1, SPI-H23_LO_SRC_COS_IN1 to the DAQ channel list for the spi model.

Wed DAY Ops Summary

TITLE: 08/12 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:

Today there was closeout work for HAM7 (with the plan of closing up HAM7 tomorrow).  Masayuki continued with overall detector work locking PRMI and working on JAC.  CDS team carried out a list of activities activiites in the afternoon (they were done in under an hour).  CRS work continued.  Jenne & Mike led a tour for small group from the Dept of Energy.

Smoke worsened rapidly around noon PDT with AQI dropping from GOOD to MODERATE  to UNHEALTHY by the end of the day. (could no longer see Rattlesnake)

LOG:

• 1520-1600 technical cleaning @lvea (kim)
  • 1635-1654 finishing off lvea
  • 1801-1849 technical cleaning at MX
• 1615 quick trip (dropping off item) to CER (ryanC)
• 1649-1749 Analog video removal in MSR (jackie,fil)
• 1720 Finishing HAM7 (sheila.ryanS.camilla)
• 1736-1755 REFL pd alignment at IOT1 (masayuki)
• 1806-1815 CRS temperature control adjustment near HAM3 (michael,shoshonna,huyen)
• 1821 HAM8 taken to ISOLATED (noticed it was in the READY state at 1614
• 1821-1838 Returning equipment in/from LVEA (gerardo)
• 1830-1847 More CRS temperature tuning (michael,jim)
• 1845-2050Hanging ladders in LVEA continued from yesterday (chris)
• 1900 Smoke worsened suddenly around noon with AQI dropping from GOOD to MODERATE (could no longer see Rattlesnake :( after being totally clear this morning)
• 1932-1950 Walthrough LVEA (betsy)
• 1941-1946 Another CER trip (RyanC)
• 1951-2027 Major CDS Afternoon activities related to frame writer + model updates + DAQ restart (jonathan,dave,eric,patrick)
• 2014-2021 grounding pins at CRS chassis/rack (michaelR,jim)
  • 2039 back to do this again (MichaelR.shoshonna)
  • 2130-2135 removing ground from pins (shoshonna)
  • 2140 & 2143 (out@2220) Return trips to the rack (shoshonna.michaelR)
• 2026 HAM7 SUS measurements (rahul)
• 2040-2123 Transitioning LVEA to SAFE (local laser hazard for HAM7 remains in effect) [corey]
• 2123-2152 inventory check (betsy.randy)
• 2126-2150 FCES CER accelerometer & cable checks (dave.miranda)
• 2131 HAM7 needs to continue close-out (sheila.camilla.ryanS)
  • 2254 sheila out & Ryan & Camilla continuing on with power measurements, taking beam into HAM6, and then removing tooling from the chamber.
• 2146-2221 measuring cables (carlos)
• 2159 BSC8 vacuum gauge (PD180) prep to replace dead guage (gerardo)
• 2208-2247 DOE tour entering LVEA (mike.jenne.richard.DOEteam)
• 2211-2301 accelerometer+cable checks @EY (dave.miranda)
• 2245-2254 Checking CER rack (richard)
• 2258 Analog video work/checks in MSR (jackie)
• 2329 taking photos of a vacuum gauge (gerardo)

PRMI locked

Summary

PRMI locked!!
The MICH loop was reworked, the PRCL gain was raised, and the REFLAIR demodulation phases were tuned. The guardian has been updated to the new nominal.

---

Loop adjustment

After aligning BS and PRM using PRX and MICH, I first tried to lock with ISC_DRMI as it was, changing nothing. It never caught after about 20 minutes of waiting in total, split between yesterday and today.

So I went back to the MICH loop. With PRM misaligned and MICH locked, I measured the open loop gain. The UGF was at 5 Hz and the phase margin sat around 20 deg across 5–10 Hz. So, I decided to modify the MICH loop and push UGF up to 10 Hz with reasonable phase margine.

The largest phase eater was the ELP35 in FM2 of BS_M3_LOCK. I loaded an ELP200 into FM3, which was free, and used it in place of the ELP35 in FM2. That loosened the phase roll-off enough to give about 40 deg of margin at 10 Hz.

Back to PRMI. MICH1 and MICH2 also carried several low-pass filters, so I switched all of them off, and it locked within a few minutes. Once locked, all of the low-passes could be switched back on without losing lock.
Repeating this, it locked within a few minutes every time.

With the lock holding I measured the MICH and PRCL loop gains. MICH showed gain bump above 10 Hz, and the PRCL UGF turned out to be only 20 Hz. Doubling the PRCL loop gain brought its UGF up to 55 Hz, and the MICH gain bump went away. This was the most stable state I found, and the time to reacquire came down to 1–2 minutes, so I took it as the nominal and edited the guardian at this point.

---

Servo change summary

Filter changes

Filter bank	Module	Change
MICH1	FM5 (LP80)	off for acquisition, on after lock
MICH2	FM2 (LP50)	off for acquisition, on after lock
BS M3 LOCK	FM2 (ELP35) → FM3 (ELP200)	permanent; ELP200 newly loaded into the empty FM3
REFLAIR_A_RF9 input matrix	—	set to 3.5, doubling the PRCL loop gain

Guardian edits

What	File	Line
MICH1 FM5	lscparams.py	530
MICH2 FM2	ISC_DRMI.py	219
BS M3 LOCK, ELP35 → ELP200	ISC_DRMI.py	298, 523, 585
REFLAIR_A_RF9 input matrix	lscparams.py	718
Engage the low-passes after lock	ISC_DRMI.py	628–630

---

REFLAIR demodulation phase

Last, I tuned the REFLAIR demodulation phases. A 50 Hz excitation of amplitude 3 was injected into PRCL1 ERR, and the phases were adjusted to minimise the peak in RF9_Q and RF45_Q. The I peak heights did not change much.

	demod phase [deg]	Q peak height
RF45	-176 → -171	0.1 → barely visible
RF9	-29 → -34	0.1 → barely visible

---

OLG

A final open loop gain measurement gave:

Loop	UGF	Phase margin
MICH	10 Hz	50 deg
PRCL	50 Hz	50 deg

Both open loop TFs are attached.

HAM7 close-out measurements - Suspensions look healthy!

Ryan C, Rahul

We have taken the pre-door close transfer function measurements on ZM1-5, FC1 and OPO and they all look healthy. I am attaching screenshots of ZM1-5 below (ZM4 results was posted by Ryan C yesterday - see alog 91486).

Ryan will post screenshots of FC1 and OPO in the comments section. 

HAM7 doors can close once seismic is happy as well.

WP 13472 - new frame writer software on h1daqfw1 + OS upgrade

Per WP 13472 the new frame writer software is deployed on h1daqfw1 and is writing frames.

We will need to do a daqd restart later to change the set of channels we are monitoring from the frame writers.  That will be scheduled with the control room.

It was done the same was as h1daqfw0.

 * Upgrade the OS in place to Debian 12

 * Apply the puppet policy

 * Restart to make sure everything loads

We will leave the nds1 redirect in place until the end of the day.

REFL AIR PD alignment check

I checked the REFL AIR PD centering at ISCT1. The centering was good from before I made move.

For the future reference, the PMC single bounce power is 2.64 at H1:LSC-REFLAIR_A_LF_OUT, and 5.5 at H1:LSC-REFLAIR_B_LF_OUT

WP 13472 - redirected queries to h1daqnds1 towards h1daqnds0

Per WP 13472 we will be upgrading the software on h1daqfw1.  In preparation for that we are redirecting all requests to h1daqnds1 onto h1daqnds0 (whose frame writer will be running through this).

 

CRS Commissioning Update Cont and Noise Hunting

8/11/26

[Huyen, Jim, Michael, Shoshana]

CRS Commissioning (from list in G2601523):

• Looked at the IMC pitch and length measurements with and without CRS in loop (picture 1, reference w/o CRS in loop)
  • Configuration: used 30mHz blend in RY, 250mHz blend in X
  • See pitch improvement (as expected), don't see much improvement in length
  • Next Steps: Will try again but next time pushing the X blend down from 250mHz to 100mHz to see if that reduces the length noise.

Noise Hunting:

• Switched CRS laser for NRS laser
  • Didn't see improvement, the NRS laser is about half the power of the CRS one, so we didn't expect a huge improvement, but we saw none at all and worse noise
• Insulated NRS laser with a large thermal mass (copper blocks) and wrapped in bubble wrap
• Tried wiggle test, turns out it was very sensitive to motion near the laser
  • The fiber makes a sharp-ish turn near the laser output due to the cover, we taped down the fiber in a way that will hopefully lessen the strain on it and take more data 

Wed DAY Ops Transition

TITLE: 08/12 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: CALM
    Wind: 2mph Gusts, 0mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.06 μm/s 
QUICK SUMMARY:

Went to EQ Mode twice overnight.  On the docket for today:  HAM7 close-out begins, Input Alignment work will continue, CDS w/ DAQ restarts in afternoon, HAM8 Annulus Ion Pump activity, & DOE tour in the afternoon.

Absolute angular calibration of the JAC steering actuators from the second harmonic of the cavity transmission.

Summary

We have calibrated the two JAC steering actuators the PZT (IO_MB_M4) and the JM1, in μrad per drive count at DC. The scale comes from the second harmonic of the cavity transmission under a dithered drive, which is insensitive to DC misalignment and so needs no external angle reference. 

---

Method

By expanding the injected field in the cavity's own eigenmode basis, we can describe the misaligned as,

Ein(t) = E0 + δ(t) E1

with E0 the cavity's TEM00 mode and E1 the TEM10 (pitch) or TEM01 (yaw) mode, orthonormal. As long as the misalignment is small enough comparing to the beam size, the single complex coefficient δ carries the whole misalignment on that axis: its real part is a transverse displacement in units of the waist size, its imaginary part an angle in units of the divergence angle. Only the TEM00 is resonant, so the transmitted power follows the fraction of the input that sits in E0, i.e. 1 − |δ|2 for |δ|2 « 1.

Dithering a steering actuator makes δ oscillate about whatever value it already had:

δ(t) = δofs + δa cos(2πft)

where δofs is the static misalignment already present, and δa is the dither we deliberately applied, which is exactly the quantity we want in order to calibrate the actuator. TRANS signal (1 − |δ|2) can devided into three components with its frequecies:

frequency	value	contains the unknown δofs?
DC	|δofs|2 + |δa|2/2	yes
f	2 Re(δofs*δa)	yes — magnitude and relative phase
2f	|δa|2/2	no

The static offset drops out of the second harmonic algebraically. 2f therefore delivers |δa| with no reference to the alignment state we happened to be sitting at, and with no external angle standard. The DC and f terms, the two one would reach for first, are both contaminated by it.

This is the whole point of the method, and it is directly visible in the plot. adding a static offset grows the 1f line by +528 % while the 2f line moves by +8 %, its own measurement noise.

---

Measurement

I proceeded 4+1 measurement in total with the JAC locked. For each measurement, one actuator axis was dithered at 11 Hz, with the excitation injected on the channels below and the drive read back on the corresponding _OUT. I excited JM1/PZT PIT/YAW per one measurement, and the other one is the PZT_PIT excitation with static offset (30 cnts) to demonstrate that the 2f peak is not affected by the offset. Transmission was read on H1:JAC-TRANS_A_LF_OUT.

record	excitation channel	drive read back on	amplitude at 11 Hz [cnt]	drive offset [cnt]	TRANS DC [cnt]
PZT_PIT	H1:JAC-PZT_PIT_EXC	H1:JAC-PZT_PIT_OUT	20.0	0	6451.2
PZT_PIT_ofs	H1:JAC-PZT_PIT_EXC	H1:JAC-PZT_PIT_OUT	20.0	30	6442.5
PZT_YAW	H1:JAC-PZT_YAW_EXC	H1:JAC-PZT_YAW_OUT	20.0	0	6442.6
JM1_PIT	H1:SUS-JM1_M1_TEST_P_EXC	H1:SUS-JM1_M1_TEST_P_OUT	40.0	0	6445.5
JM1_YAW	H1:SUS-JM1_M1_TEST_Y_EXC	H1:SUS-JM1_M1_TEST_Y_OUT	40.0	0	6440.2

|δa| is calculated from peak heights of the transmission at 22 Hz, converted to a mirror tilt using the local beam radius at each actuator from the current JAC reflected-path layout model (alog91472 comment), and calibrated into DC responce using each actuator's frequency response as measured (described below).

---

Results

actuator	axis	excitation channel	|δa|2	efficiency [μrad/cnt]
				at 11 Hz (as measured)	at DC
PZT	PIT	JAC-PZT_PIT_EXC	1.09e-5	0.0093	0.083
PZT	YAW	JAC-PZT_YAW_EXC	6.47e-6	0.0093	0.079
JM1	PIT	SUS-JM1_M1_TEST_P_EXC	1.01e-5	0.0216	0.89
JM1	YAW	SUS-JM1_M1_TEST_Y_EXC	1.67e-5	0.0254	0.92

The 11 Hz column is what the dither actually produced; the DC column is that value divided by the actuator's own response at 11 Hz, and is the number to use for a DC gain. 

---

Appendix

Actuator frequency response

The frequency response itself comes from a separate set of four broadband actuator-to-wavefront-sensor records (300 s each, one actuator per record, see atatched plots), from which the JM1 suspension resonance and the PZT drive pole are fitted. Only the shape of those transfer functions is used; their absolute scale plays no role in the calibration.

The fitted frequency responses are:

• JM1 — complex pole pair, f0 = 2.00 Hz, Q = 7.7 (PIT) and 1.80 Hz, Q = 5.4 (YAW)
• PZT — single real pole at fp = 1.24 Hz (PIT) and 1.30 Hz (YAW)

AOI compensation

Both actuators sit at a design AOI of 45°, and the rows above include the geometric correction that follows. A tilt whose rotation axis lies in the mirror surface and in the plane of incidence steers the beam by only 2θ cos(AOI), against the full 2θ for the axis perpendicular to that plane. At the PZT the suppressed axis is YAW in the cavity-referred channel naming (the HAM1 periscope exchanges the transverse planes downstream of it); JM1 sits after that periscope, so for it the suppressed axis is PIT. The assignments follow from each mirror's orientation, and the correction uses the design 45° rather than a value fitted to the measured ratio.

Cross-checks

• JM1 against its own OSEM signal. I compared the numbers above with the OSEM output with a rough single DC-step reading. The difference between the calibration factor are: 1.17× (PIT), 1.02× (YAW). 
• PZT against its design value. The design chain is APZT = 500 μrad/V (T1500342) driven through an 18-bit DAC (±10 V differential, i.e. 20 V over 2¹⁷ counts) and a differential-to-single-ended board (D1100457 v2, unity gain, read off its schematic), giving 0.076 μrad/cnt. No further driver gain applies on top, since the T1500342 figure is referenced at the controller's control input. Our result sits at 1.09× (PIT) and 1.04× (YAW) of this designed value.

PSL 10-Day Trends

FAMIS 63911

PMC REFL has been rising very slightly, but otherwise, no major events of note.

X-Arm Peek, GV8 Open for the Day

(Travis S., Gerardo M.)
Around 11:00 am today we opened GV8 from soft close to allow for commissioners to peek down x-arm.  The gate annulus for GV8 was burped into the annulus ion pump, almost no response.  The 4 turbo pumps were isolated from the main vacuum envelope, the 4 large ion pumps are valved in, along with HAM6 ion pump (500 l/s), and we still have a filter cavity section valved into the main corner volume, the section from FCV-3 to FCV-4, and includes ion pump B-1 (150 l/s).
GV8 remained open for about 5 1/2 hours.
We closed GV8 around 16:30 local time.
Attached is a pressure response from gauges along the X-arm at the corner station.

OPS Tuesday day shift summary

TITLE: 08/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: GV8 was opened and closed today for Xarm alignment commissioning, ZM4 PSAMs adjustment was finished up. We had a small power glitch in the afternoon that tripped off the end station HEPIs.
LOG:                            

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:33	FAC	Kim	LVEA	Y'	Tech clean	15:11
14:59	FAC	Chris	LVEA	Y	FAMIS checks	15:26
15:26	FAC	Chris	All Out BLDs	N	FAMIS checks around site	17:44
16:09	SEI	Carlos	LVEA	Y	Seismometer checks	16:55
16:16	SEI	Jim	LVEA	Y	SPI checks	16:28
16:37	OPS	RyanC	LVEA	Y -> N	LASER hazard transition, hazard to safe	16:47
16:48	EE	Fil	LVEA	N	Check JAC shutter connections	16:52
16:48	EPO	Jenne	LVEA	N	Tour	17:30
16:52	EPO	Camilla	LVEA	N	Tour	17:25
16:54	SQZ	Rahul, RyanS	LVEA	Y/N	HAM7 work, bifurcated laser hazard area	18:15
17:21	EPO	Corey	LVEA	N	Tour, in @ 12:00	17:34
17:46	OPS	RyanC	LVEA	N -> Y	Laser hazard transition, safe bifurcated to hazard	17:58
17:48	VAC	Gerardo, Travis	LVEA	YES	Opening GV8 (XARM)	18:13
18:07	PEM	Michael, Shoshana, Huyen	LVEA	Y	NRS hardware under ITMY, Huyen out 18:21	19:45
18:22	ALS	Jennie, Masayuki	LVEA	Y	ISCT1 table checks	18:45
18:29	SEI	Jim	CER	Y	Quick check SPI, CER maybe LVEA	18:32
19:12	ALS	Sheila, Masayuki	LVEA	Y	ISCT1 alignment checks	19:26
19:15	ISC	Betsy	LVEA	Y	Checks	19:22
19:29	CDS	Dave	CER	Y	Accelerometer checks	00:28
19:43	CDS/SAF	Patrick	MSR	N	Beckhoff safety computer investigation	20:03
20:01	FAC	Randy	LVEA	Y	Clean room checks	20:58
20:02	EE	Fil, Jackie	EndX	N	Reset VFD and remove analog cameras	21:07
20:02	SEI	Jim	EndX	N	Reset VFD recover HEPI	20:33
20:03	SQZ	RyanS	LVEA	Y	Beam profiles at HAM7	21:50
20:23	SQZ	Rahul	LVEA	Y	HAM7 work, ZM4	21:23
20:59	FAC	Randy	EndY then X	N	Clean room checks	21:59
21:08	EE	Fil, Jackie	EndY	N	Remove analog cameras	21:39
21:25	ALS	Sheila, Camilla	LVEA	Y	ISCT1 beatnote adjustment	22:01
21:21	SEI	Jim, Huyen	FCES	N	CPS checks/tests	21:45
21:37	SAF	Richard	Mechanical	N	HEPI pump checks	21:50
21:39	EE	Fil, Jackie	CER	Y	Remove analog camera electronics	23:21
22:11	PEM	Shoshana, Huyen	LVEA	Y	CRS laser	22:24
22:19	ISC	Sheila, Masayuki	LVEA	Y	ISCT1 alignment checks	23:00
22:58	SEI	Michael, Jim	LVEA	Y	Wiggle SPI cable, look at other cabling at TCS rack	23:58
23:10	VAC	Gerardo	LVEA	Y	Close GV8	00:28
23:22	EE	Fil, Jackie	MSR	N	Remove analog camera electronics	00:22

The gate phone microphone doesn't seem to be working well, one instance I heard nothing after answering, the next was garbled and full of static.

• 16:45 UTC transition to Laser Safe bifurcated
• 18:00 UTC transition to Laser Hazard
• 18:06 UTC GV8 is open
• 18:15 UTC started with the baffleAlign scripts
• 19:48 UTC a  power glitch flickered the lights in CR and tripped the End station HEPIs then ISIs
  • Fil&Jackie to EndY, Jim to EndX, to reset VFD plus other work for Fil
• 20:57 UTC BS ST2 ISI tripped
• 21:12 UTC Xarm locked in green with ir flashing
• 22:00 UTC I ran a health check TF on ZM4 after Rahul and RyanS were finished at HAM7
• 23:00 UTC Masayuki requested Aquire_PRMI in ISC_DRMI and there were flashes ~100
• 23:22 UTC GV8 soft closed

arm peak today, COMM beatnote and PRMI flashes.

Camilla, Oli, Caroline, Masayuki, Sheila

• Before starting the arm peak Masayuki and I aligned PRX and MICH based on the alignment that Louis aloged in 91463  We are seeing flashes of up to 150 coutns on LSC POP A, 130 counts on the ASC POP QPDs, and nothing in POPAIR.  (1st screenshot)
• Once the gate was opened we ran the TMS to ITM baffle PD script without issue.  Caroline and Oli searched for the ETM baffle PD using an awg, and found it, then were able to run the baffle PD script for ITMX.  (2nd screenshot)  This ITMX pitch is different by 50urad.  
• We moved PR3 back to it's O4c alignment, Masayuki and Sheila went to ISCT1 to look for single pass green beam.  We saw it but very low in pitch, adjusted PR3 alignment to put it on the ALS X camera and trans PD.
• Camilla, Oli and Caroline tried to align ETMX using the baffle PD script, but this didn't work well. Once the table was aligned the switched to rastering the ETM and watching for flashes in the camera and trans diode.  
• Just as they were starting to see the flashes, the site power glitched and the HEPI pump controllers went down.  Jim went to EX to bring it back.
• Meanwhile, 10W single bounce off ITMX Masayuki moved IM4 to center the beam on POP X, and PR2 to bring the ITMX reflection onto the REFL PDs and refl camera.  After that worked he aligned PRM to get PRX flashes, then aligned BS for mich fgringes. 
• The single bounce beam looked clipped when SR2 was adjusted to center on the AS camera and AS_C, although the power on AS_C seems correct (0.02W into HAM6 with 9W on IM4).  When we moved SR2 to being the beam high on the camera and QPDs it looked like a normal shape.  Masayuki walked BS and SR2 to try to correct this.  
• Once HEPI was recovered we found the arm flashes in green and locked.  We could not engage slow feedback to the ETM but requested LOCKING from the guardian.  
• Camilla and Sheila aligned the COMM beatnote on ISCT1, and slightly adjusted PR3 pointing to avoid clipping on the path to the beatnote BS.  We got a beatnote of 0dBm, but we can see that the beam is slightly clipped on the prism.  
• Masayuki aligned IM4 and PR2 to get IR aliged to the X arm.  He was able to lock it with a normalized power of 0.95 (close to the nomial 1).
• Masayuki aligned PRM using PRX, and BS using MICH. 
• Sheila and Masayuki went to ISCT1, moved the POP top periscope mirror closer to REFL and down.  We should move the whole periscope over towards refl soon, to center on the pop top periscope mirror.  Then we aligned the rest of the path through to the POPAIR B diode, we see 120 counts on RF18.  
• Masayuki double checked the beatnote, it is -1dBm.  (final screenshot)

ZM4 PSAMs Preload Adjusted (Again, Final)

R. Kumar, S. Dwyer, C. Compton, R. Short

Following the work done yesterday adjusting the preload on the ZM4 PSAMs (alog91471), Rahul and I set about adjusting it further today to get our calculated projected beam size on SRM close to where we want it. Using the same procedure as yesterday, I turned off the ZM4/5 PSAM drive chassis, Rahul went into HAM7, locked down ZM4, torqued the preload about 1/8" of a turn (it's hard to quantify a torque spec in this manner), then finally unlocked the suspension. I moved the ZM4 pitch alignment slider about -1400 counts to realign the beam on SQZT7 to our alignment irises as a result of this torque adjustment. I then proceeded to take a couple of beam profiles on the table with the M^2 device to see where we landed. This plot [initial] shows the difference between before and after this adjustment in terms of the projected beam at SRM with a few different PSAM settings on ZM4 and ZM5. The four points I took here informed us that we could stand to torque ZM4 a bit further to hopefully line up with the center of the plot.

Rahul went back into HAM7 and torqued another 1/8" and I took another couple of profiles after (I did not need to move ZM4's alignment sliders after this adjustment). I took a total of nine profile points here, all of which can be seen compared to other measurements today on this plot [full]. Since there are points in the bullseye, we decided to stop here and that this is where the ZM4 preloading will stay. This plot [final] shows just the beam profiles taken at our final preloading position.

Tomorrow we will move on to final closeout checks in HAM7.