Centered the ISS second loop array, using picomotor 1. The QPD signals were zeroed, and in that state all PD powers were high and quite similar. See first attached plot.

For reference, the typical power levels measured before are (18054)

Note that the normalization of the signals might be different, as well as the input power, so only the relative differences are important. The distribution of power levels is comparable with the old measurements.

With the IMC offline, measured and retuned the dark offsets:

H1:PSL-ISS_SECONDLOOP_PD1_INMON 507.360238647
H1:PSL-ISS_SECONDLOOP_PD2_INMON -0.477651876211
H1:PSL-ISS_SECONDLOOP_PD3_INMON -4.05748717785
H1:PSL-ISS_SECONDLOOP_PD4_INMON -4.37042988539
H1:PSL-ISS_SECONDLOOP_PD5_INMON 0.0666494309902
H1:PSL-ISS_SECONDLOOP_PD6_INMON -0.540560656786
H1:PSL-ISS_SECONDLOOP_PD7_INMON -1.43365537077
H1:PSL-ISS_SECONDLOOP_PD8_INMON -0.803998035192

They're all normal, except for PD1 which has a very large offset.

More  preparation for opening up the Y-arm Monday.

Updated the ALS code in the X end station TwinCAT and switched to the new LaserLocking library. The medm screens were updated as well. Seems to work.

TITLE: 06/08 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC

STATE of H1: Planned Engineering

INCOMING OPERATOR: None

SHIFT SUMMARY:

15:00 (8:00) Start of shift

15:05 (8:05) Mark to LVEA -- collect rigging equipment

16:11 (9:11) Marc to EX -- grab timing comparator

16:21 (9:21) Robert to PSL

16:32 (9:32) Fil to LVEA

16:40 (9:40) Marc back from EX

16:48 (9:48) Kyle to EX VEA

18:51 (11:51) Robert to IOT2

19:02 (12:02) Georgia and TVo to LVEA -- look at IMC open loop transfer function

19:08 (12:08) Georgia and TVo back from LVEA

19:24 (12:24) Robert back from IOT2

20:01 (13:01) Mark and Tyler to EX -- mechanical work

20:10 (13:10) Kyle and guest to LVEA -- informal tour

20:32 (13:32) Jeff B to LVEA -- work on ITM cameras

20:34 (13:34) Georgia and Craig to LVEA -- look for router

20:37 (13:37) Ed and Marc to EX -- reinstall chassis

20:48 (13:48) Fil to LVEA

20:53 (13:53) Kyle, guest out of LVEA

20:57 (13:57) Ed and Marc back from EX

21:10 (14:10) Georgia and Craig back from LVEA

21:20 (14:20) Jeff B back from LVEA

21:30 (14:30) Kyle to LVEA -- open valve on pump cart

21:36 (14:36) Ed to LVEA -- look for wireless router

21:46 (14:46) Richard and Fil to LVEA -- look at temporary wiring

21:53 (14:53) Chandra to LVEA -- valve ion pumps

22:07 (15:07) Richard and Fil back from LVEA

22:08 (15:08) Kyle out of LVEA

22:08 (15:08) Kyle to EY

22:15 (15:15) Ed back from LVEA

22:40 (15:40) Chnadra back from LVEA

22:47 (15:47) Kyle back from EY

22:50 (15:50) Sheila and Hang to LVEA -- moving REFL9 phase shift from digital to analog

22:54 (15:54) Marc and Robert to vault

23:00 (16:00) End of shift

Today we set up a method of quickly taking transfer functions of the IMC using an SR785 in the LVEA.
Richard plugged in a GPIB to the CDS network and activated the port at IP 10.22.10.31, GPIB address 10.  
I was then able to quickly take an IMC OLG transfer function using EricQ's netgpibdata scripts, in particularly the SRmeasure script which tells the SR785 what to measure and returns the data.  
This is very useful because the IMC has been unlocking over the past few days, but if we wanted to check the OLG for instability we had to go into the LVEA.

At 11 Watts input power, the IMC OLG is 30 kHz with 58 degrees phase margin.

E. Merilh, M. Pirello

Today we completed the modification to the Timing Comparator chassis at X-END, the following work was completed on each chassis.

E1800008-v1 Replace 5V regulator with separate power supply.

E1200034-v6 & E1700246-v1  Add more frequency counters to unused Timing Comparators channels.

Previous Alog can be seen here ALOG40064

This completes the work on the timing comparators and closes:FRS4910  WP7383

J. Kissel, H. Radkins

Something appears to have gone terribly wrong after Friday Jun 1 with the ISI HAM6 performance below ~0.2 Hz. Given that frequency range, first suspects are CPS and Sensor Correction. More likely to be CPS, given Hugh's battle with them during the vent (see e.g. LHO aLOG 41204). 

I've informed Hugh and will file an FRS ticket.

Attached plots stolen from the summary pages show the performance of the table on Jun 1, Jun 2, and today (Jun 8) 2018.

I valved-in IP2, IP5, IP3 and IP4 and, concurrently, valved-out the YBM, XBM and Vertex turbo pumps.  Additionally, I connected a pump cart to GV5's annulus pump port and removed the pump cart from IP3.  Assuming the IPs stabilize and GV5's AIP can run unassisted, we should be ready to open the Y-arm on Monday,

Fil, Jeff B, Dave:

the Mid-Y weather station is once again operational after the CP4 bake-out hiatus. The AC converter on the Comtrol unit had failed and was replaced. Jeff B noted that the WIKI instructions are specifically to start the code from scratch, and does not cover stopping the currently running code (inside a screen session). This system will be upgraded to Beckhoff, so we will resolve documentation at that point.

This completes WP 7632. No issues encountered. There are now three EtherCAT NIC cards installed with two ports each. These now fill all the available slots.

   Removed End-X VEA2 dust monitor from the check_dust_monitors_are_working script. Have committed the updated script to the SVN repository. The dust monitors added to support the various chamber openings have all been removed as the chambers were closed. The dust monitoring scheme is back to an observation run status.     

With the OMC locked on a singel bounce beam and 10W of input power, I started a slow scan of the IMC VCO using a script that Anamaria sent.  The scan started at 1212469399, or 10:03 local time.  The script is set to run for 12 hours.  

If anyone needs to stop it the matlab session that is open on ZOTWS11 (front corner next to Hugh) is scanning the VCO.  

This is for a comparison to the measurements in LLO log 39247

Gabriele Sheila Georgia

The spectra we took yesterday were taken with the ISS unlocked. We have retaken the IMC-WFS and IMC-IM4_TRANS spectra with the ISS locked and conclude that we are not currently seeing excess jitter as, if it was, we should be able to see it in IM4_TRANS.

The first attachment shows the WFS (pink, green, cyan, brown traces) and IM4_TRANS spectra (blue, red traces), uncalibrated, both measured with the IMC and ISS locked. The coherence between the WFS and IM4_TRANS (bottom plot) is now dramatically reduced compared to alog 42362, i.e. the peaks we see in the WFS are not on the beam entering the interferometer. This plot suggests that the noise is coming from IOT2. The peaks in the IM4_TRANS pit and yaw spectra are also present in the sum output of the PD.

The second attachment shows the beam-widths-calibrated spectra from alog 42373, with the IMC locked at 10 W for the IM4_TRANS (yellow, black), bullseye PD (red, blue), and unlocked for the WFS spectra (pink, green, cyan, brown traces). The low frequency IM4_TRANS spectrum is quieter, and the coherence with the bullseye is no longer high. If the peaks in the IMC-WFS spectra were due to beam jitter they should be visible in IM4_TRANS.

Also note for these plots we have not yet addressed the sqrt(2) error in the bullseye calibration.

Thomas, Sheila, Georgia

Summary

We have calibrated the width, pitch, and yaw outputs of the PSL bullseye PD, accounting for the larger beam size incident on the detector.

We then compared the PSD at the bullseye with the IMC-WFS (on reflection, measured with IMC unlocked) and IMC-IM4_TRANS (with IMC locked) to look for jitter coupling.

The jitter measured by the bullseye PD is 2-3 orders of magnitude below the WFS noise, implying that our jitter does not originate from the 70 W amplifier.

Bullseye PD calibration

Keita reported yesterday on the installation of the bullseye PD, on a pick off directly after the 70 W amplifier stage (alog 42344). TVo and I set about updating the filter banks, which convert the individual segments to width, pitch and yaw, relative to the beam width on the photodiode. We calculated the beam width based on the power on the outer and inner segments, and following Vaishali and Kiwamu's note (DCC-T1700126) calculated the new responses. The new gains are:

g_width = 0.55

g_pit = 0.61

g_yaw = 1.06

Which is only a few percent off the previous gains.

Comparing bullseye PD and IMC spectra

To calibrate the bullseye PD, IMC-WFS, and IMC-IM4_trans such that they can be compared quantitatively, we did a calibration similar to alog 39434 - including the PMC and IMC suppressions, and converting the IMC PDs to units of beam width. The bullseye raw data is multiplied by the PMC and IMC suppressions; the IMC-WFS data is multiplied by the IMC suppression and the factor of sqrt(pi/8) to convert to units relative to beam width, and the IMC-IM4_TRANS data is multiplied by the factor of sqrt(pi/8).

The PMC suppression was calculated from DCC-T0900616, S_PMC = 0.0163. The IMC suppression was calculated from DCC-T060269, and the finesse from DCC-G1400096, giving S_IMC = 0.0039.

The calibrated plot is attached. The bullseye PD spectra are well below the IMC-WFS (showing lots of jitter) and IMC-TRANS traces.