Shift Summary - Day

TITLE: 06/07 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:

14:53 (7:53) Jeff B to LVEA H2 Chiller Room -- look for parts

15:00 (8:00) Start of shift

15:06 (8:06) Ken to EX, EY -- electrical work

15:40 (8:40) Jeff B back from LVEA

15:50 (8:50) Christina to EX, EY -- drop off first aid kits

16:50 (9:50) Jason to PSL enclosure -- investigate temperature spike

16:54 (9:54) Jeff B to EX -- recover contamination control kit

16:57 (9:57) Marc to MX -- testing vault magnetometer

17:03 (10:03) Hugh to EX -- check out HEPI pump

17:31 (10:31) Jeff B back from EX

17:31 (10:31) Jeff B to PSL -- make measurement

17:45 (10:45) Jason to LVEA

17:50 (10:50) Hugh back from EX

18:18 (11:18) Georgia and Craig to EX -- pack up EFM equipment

18:22 (11:22) Ed and Jason to EX -- pack up alignment equipment

18:33 (11:33) Marc back from MX

18:48 (11:48) Craig and Georgia back from EX

19:11 (12:11) Jeff B out of PSL enclosure

19:30 (12:30) Jason and Ed back from EX

19:41 (12:42) Jeff B and Jason to PSL enclosure -- make sure environmental controls are set right

19:50 (12:50) Jeff B and Jason back from PSL enclosure

20:28 (13:28) Fil to LVEA‌ -- Beckhoff upgrade preparation

20:35 (13:35) Gerardo to EX -- purge air skid

20:51 (13:51) Ken to EX -- work on overhead door switches

21:07 (14:07) TVo to LVEA -- Set up barriers around CO2 laser tables, open and start them, inject CO2 into chamber

21:12 (14:12) Marc and Ed to vault

21:40 (14:40) Ken back from EX

22:25 (15:25) Marc and Ed back from vault

22:59 (15:59) TVo back from LVEA

23:00 (16:00) End of shift

Wrong reference cavity resonance

Noticed that the EX ALS laser wouldn't lock. After last Tuesday, the PSL was locked to the wrong reference cavity resonance. Unfortunately, this shifts the frequencies of the ALS and SQZ lasers by ~600MHz.

New ALS Parameters

The new green power transmission coefficients for the test masses are:

	Old	New
ETMX	37%	7.9%
ETMY	32%	7.9%
ITMX	1.1%	0.96%
ITMY	1.1%	1.1%

Assuming 10 mW input power, the expectations for the new arm cavity parameters are:

	Old		New
	X-arm	Y-arm	X-arm	Y-arm
Finesse	13	16	68	67
Cavity Pole	1.4 kHz	1.2 kHz	275 Hz	280 Hz
Intra cavity power	83 mW	99 mW	390 mW	380 mW
Reflected power	9.1 mW	8.9 mW	6.2 mW	5.8 mW
Transmitted power	0.9 mW	1.1 mW	3.8 mW	4.2 mW

The attached plot shows cavity power and PDH signals for fundamental, first-order and second-order modes as function of round-trip wavelength. The left column is for the old cavity parameters.

Weekly PSL Chiller Reservoir Top-Off

Added 50 mL to crystal chiller

Two additional NIC cards added to h1ecat0

Finished WP 7631. The HEPI pump servo appears to have continued to run unaffected.

PSL PMC Beam Alignment Tweaked

E. Merilh, J. Oberling

We tweaked the beam alignment into the PMC this morning (done via picomotors from the control room).  When we started the PMC was transmitting ~19 W, upon finishing the PMC was transmitting ~39.8 W.  This is not quite at the 42 W we were transmitting after Peter and I installed the ISS AOM; this may be due to the temperature being ~10 °F hotter than normal, will monitor the PMC trans once PSL temps return to normal.

After the tweak we turned the ISS ON.  The Reference Signal was set to -1.70V, which gives a 1.5% diffracted power percentage.

PSL Weekly Report - 10 Day Trends FAMIS #6739

70W Laser power anomalies due to Bulls-eye swapping and calibration. All other plots seem nominally ok.

Beam jitter on PSL bullseye PD

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.

MICH_BRIGHT dither alignment, IMC unlocking

This afternoon and this evening the IMC has not been staying locked for long, 10-30 minutes at a time.  Thomas and I checked the OLG, which seems fine at around 40kHz.  The alignment of the IMC also seems fine. 

I don't know what the problem is.  Earlier this afternoon I disabled the ISS since that was railing, Jason is planning to adjust the alignment into the PMC in the morning which will probably help.  We can see if the PMC adjustment tomorrow helps with the problem.  

We were planning to set up a single bounce measurement with the IMC VCO scan, but since it is a long measurement it won't work with the IMC not staying locked.  

Earlier tonight I also started a guardian state for a MICH dither alignment in the ALIGN_IFO guardian.  The plan is to replace the step that operators do by hand in the initial alignment, Craig and I I edited PREP_MICH_BRIGHT_ALIGN to set up the oscillators and demods, and checked that the signals look promising.  This job will also be easier to finish with the IMC staying locked.  

HWS code moved out of USERAPPS folder

I’ve removed the HWS code from the current working copy of the CDS SVN. These changes are in Committed Revision 17358.

We're moving the code to a separate GIT repo so we can get a working copy back up to the sites.

(see LLO aLOG 39308)

ETMY oplev 3rd whitening stage switched on & Laser moved to quieter location.

[Robert S. , Jason O., Suresh D.]

Objective: 

    1) At present the oplev signal is dominated by electronic noise above 1 Hz.  In attempt to see if increasing the whitening helps wished to increase the whitening stages on the signal.

    2) We wished to investigate the EMI emission from the He-Ne laser power supply using the magentometer.

Things we did:

    1) First, Robert investigated the EMI emissions.  During this process we shifted the location of the He-Ne laser and its power supply to a new location that is further away from all other power supplies and electronic devices.   See picture below.  Robert will report on the results of this investigation in a separate alog.

    2) Then Jason switched on the third analog whitening stage and also the digital dewhitening stage on the ETMY oplev QPD segments.  The new dip-switch state on the binary switch card is attached.  

Note:  We also reduced the gain by about 20dB, because at high gain of 39dB, switching  on the third whitening stage probably caused saturation of  an opamp in the chain and the output signal flipped sign.  

We will analyse ETMY oplev signals under this new condition and see if we can get a better signal to noise ratio than before.

Progress on Suspension Health Checks Post-Pump-Down

J. Kissel

I'm slowly working through measuring the standard health-check transfer functions and ASDs for all suspensions now that most chambers are closed and pumped down. I'm seeing a few suspicious things along the way that I'll need to go back and run more tests (see "notes" below), but for now I'm moving on when I see weird things, trying to get all that are "OK to GO" measured and confirmed good. I list the progress below. Where there are suspensions that are "OK to GO" I list the date of the measurement.


Suspension       Measured          Data Processed       Notes
RM1              Not Yet                n/a
RM2              Not Yet                n/a

MC1              Not Yet                n/a
MC3                 |                    |
IM1                 |                    |
IM2                 |                    |
IM3                 |                    |
IM4                 |                    |
PRM                 |                    |
PR3                 V                    V

MC2              Not Yet                n/a
PR2              Not Yet                n/a

BS               Not Yet                n/a

ITMX             M0 done, R0 Not Yet    Not Yet           

ITMY             M0 done, R0 Not Yet    Not Yet

ETMX             Not Yet                n/a
TMSX             Not Yet                n/a

ETMY             Yes                    Not Yet            All good. 2018-06-05_2125, 2018-06-05_2244
TMSY             Somewhat                                  Suspiciously nasty Roll to Roll TFs. Need to investigate further.                    

SR2              M1 done                Not Yet            Icky looking results with currently desired alignment offsets. Took "no offsets" data -- looks good. Need to investigate further

SR3              M1 done                Not Yet            All good. 2018-06-06_2256 
SRM              M1 done                Not Yet            Icky looking results with currently desired alignment offsets. Took "no offsets" data -- looks good. Need to investigate further
OFI              M1 done                Not Yet            All good. 2018-06-06_2308
ZM2              M1 done                Not Yet            All good. 2018-06-06_2323

OM1              Not Yet                n/a
OM2                 |                   n/a
OM3                 |                   n/a
OMC                 |                   n/a
ZM1                 |                   n/a
OPO                 V                   n/a    

X-End MTP Now On Scroll Pump

Switched the configuration from QDP80 to scroll, to be able to do the switch, pump down was interrupted for a bit.