Can we get new MEDM screens for the TMSY (incl. the little DRIVE CAL screens!). Also, maybe we want to update the safe.snap file ...

Attached are plots of dust counts > .5 microns in particles per cubic foot. Also attached is a plot of the mode of the dust monitor in the clean room over HAM3 (H0:PEM-LVEA_DST15_MODE). This shows when the dust monitor was swapped (see earlier entry).

Attached is a spectrum from last night (7 August 2012), starting a ~23:30h.

There seems to be a narrow spike at 700mHz, while the 2.74 Hz peaks are still there. I guess we nudging downwards ...

After syncing up the userapps/release SVN files on h2build I rebuilt most of the H2 models during Tue maintanance and restarted most models.

A problem with the folding mirror sus models was resolved with a new BSFM_MASTER file. We will install new h2susfmy code tomorrow.

New Dolphin and RFM IPC between ISI and SUS was installed today by Vincent, replacing the EPICS comms link.

New slow channels for PEM (DUST monitor) and HWS were added to the H2 frame.

h2iscey model was changed for ISC -> ALS name change. Please see Bram's alog for details.

I have installed the sender part of the new H1 IOP SUS watchdog system, making changes on h1sush2a and h1sush34. I'm also creating the new MEDM screen.

Tomorow I'll work on the h1seih23 receiver part and start testing of this system. This will be the first use of the H1 Dolphin IPC system.

MC2 - got external cables - Filiberto
HEPI models updated - Vincent
Renaming ISC to ALS at EY - Daniel/DaveB
HAM2/HAM3 - update models - Hugo/DaveB
Craning in the LVEA - Kyle and Apollo
EY - misc. work - OATers
EX - Apollo
HAM3 work - Betsy/Travis
Cleanup under H1 input beam tube - LIGOites
H1 PSL work - MichaelR

We have completed the rename of all of the H2 ISC channels to conform to the new standard:

H2:ISC-ALS_  -->  H2:ALS-
H2:ISC-ASC_  -->  H2:ASC-

While we were at it we renamed the _EY_ to be just _Y_.

This involved a couple of steps:

Modify h2iscey model

This was basically just a matter of putting the ALS and ASC library part blocks in top level sub blocks that use top_names, and then giving them the appropriate names ("Y") to ggenerate the correct channels.  The recompiled model then generated the correct names.

We did run into one issue which might be a bug in the RCG.  The auto-generated ADC screens (e.g. H2ISCEY_MONITOR_ADC0.adl) are not being generated with the correct channels. For instance, "ASC_Y_TR_A_SEG1 (adc_0_0)" is pointing to "H2:C-ASC_Y_TR_A_SEG1_INMON". The channel should be "H2:ASC-Y_TR_A_SEG1_INMON". I have no idea what is trying to do there, but we need to file a bug against the RCG

Update MEDM screens

We modified the following adl files:

isc/h2/medm/OAT.adl
isc/common/medm/QPD_OVERVIEW.adl
isc/common/medm/ISC_CUST_ALS_WFS_SETTINGS.adl
isc/common/medm/ALS_CUST_WFSDC_FE.adl

Mostly it was simple sed string replacements:

sed -i -e 's/:ISC-ALS_EY_/:ALS-Y_/' -e 's/:ISC-ASC_EY_/:ASC-Y_/' OAT.adl

There was a little bit of itteration, since we had to fix macro, screen links, channels, etc., but it wasn't bad.

Update filter files

This was also pretty simple:

sed -i -e 's/ALS_EY_/ALS_Y_/' -e 's/ASC_EY_/ASC_Y_/' H2ISCEY.txt

Restore EPICS values

We restored all the EPICS values by taking a burt snapshot file from this morning, and again performing a simple sed replace on the channel names:

sed -i -e 's/H2:ISC-ALS_EY/H2:ALS-Y/' -e 's/H2:ISC-ASC_EY/H2:ASC-Y/' h2isceyepics.snap

The updated snapshot file then burt restored all the new channels to their corresponding values before the change.

All in all, things went pretty smoothly and quickly.  I'll let the on-site guys comment on recovery of the lock after the changes.

Attached are plots of the OLTF of the PLL, taken from 1 to 50kHz, with a 200mV excitation.  The unity gain frequency is 28.7Hz at a phase of 229 degrees.  I've also included plots of a scan from 40-45kHz  where we were seeing a peak in the TF magnitude at 42.5kHz.

Around 2:30 on August 7, 2012 I attached 5 grounding plugs to the "TEST IN" connections at the Y end station.  At this time, all ITMY and ETMY coil driver boxes (for TOP, UIM, and PUM) have grounding plugs connected to each of the TEST IN connections.  I then took some power spectra measurements of the coil driver NoiseMonitor channels to see what effect the grounding plugs have on the coil driver noise.

Starting with ETMY, the UIM driver board didn't exhibit any significant change between COIL IN and TEST IN configurations.  This is because the noise in the coil drivers is dominated by component noise, and selecting the TEST IN state allows one to see the component noise without the added DAC noise.

The ETMY PUM driver board is dominated by DAC noise, since the PUM driver is not filtered as much as the UIM board in the lowest noise mode.  Therefore when we switch to the TEST IN state, the expectation is that the noise in all coil drivers should drop to the component self-noise level.  This is what we are seeing now, as compared to Jeff K's alog #3111 when the noise levels increased and the frequency dependence was different for those channels.

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=3111

For the ITMY, the UIM behavior is generally the same as on ETMY coil drivers.  However, the ITMY PUM driver shows an increase in noise after switching to the TEST INPUT with grounding plug attached.

Due to a calibration error, the dust monitor at location 15 in the LVEA (in the clean room over HAM3) was swapped. It was removed around Aug. 8 17:20 UTC and the new one put in around Aug. 8 18:01 UTC.

This is the transfer function between the phase-frequency discriminator and the FET IQ demodulator while the cavity is locked. The blue trace is "initial" conditions, i.e., with a well-aligned cavity and standard modulation sidebands. The green "sb shift" trace was taken with the RF modulation sideband frequency tuned 200 Hz higher than its initial value. The red "alignment shift" trace was taken with the ITM yaw misaligned. 

The FSR is 37.512 kHz, with a higher-order FSR peak at 75.018 kHz. Given this FSR, the cavity length is 3995.95 m.

The peaks due to the RF modulation sidebands are at 54.432 kHz and 58.098 kHz in the initial trace. These peaks shift 200 Hz in the green trace.

Additional structure is observed at 46.301 kHz, 55.325 kHz, 57.252 kHz, and 66.229 kHz. The peaks at 46.301 kHz and 66.229 kHz increase for the case of yaw misalignment and are thus likely to be (1,0) modes. 

The separations between these peaks are:

75.018 - 66.229 = 8.789 kHz

66.229 - 57.252 = 8.977 kHz

46.301 - 37.512 = 8.784 kHz

55.325 - 46.301 = 9.024 kHz

The mean modal spacing is 8.8935 kHz.

From this modal spacing, the g-factor is 0.540532, corresponding to approximate mirror radius of curvature of 2302.86 m. 

The FWHM of the FSR peak is approximately 94 Hz. Finesse is thus 37512/94 = 399.064. This would occur for a reflectivity of about 99.2%.

There's a follow-up of this in the works for characterizing cavity properties during ring heater use.

I turned on the ETMY RH, requesting 630mA from each ring heater segment. This equates to roughly 30W of power input into the ETM. I'm monitoring the Hartmann sensor signal to check for a response.

The ITMY YAW was set to zero (from 717.81 counts) to keep the cavity from resonating or flashing during this measurement.

The time constant of the ring heater is several hours, so we will run this at least until noon.

I locked the arm and did a dither alignment (>8000 on the REFL diode) and engaged the off laod at 23:10h local time, so good times are from 23:15pm.

With the work on the RefCav I will be keen to see the noise at higher frequencies. Vincent reinstalled the boosts on the ISI isolation, so all should be nice.

Should be good for the night.

Attached are plots of dust counts > .5 microns in particles per cubic foot. The dust monitor in the clean room over HAM 3 (location 15) has a calibration failure. I'm not sure when it started, but I think it was sometime today.

I was only able to test ~20 joints today on the Vertex due to leaks.  Aaaargh!  At this rate, I'll need two or more additional days to finish!  A few of the leaks were on "legacy" joints circa 1998 but most were on new aLIGO joints.  I was able to retorque and get most of these to seal but this wastes time and is "not on the schedule" - better to do it right the first time!

During the reboots I took the opportunity to have another look into the OAT RefCav in the optics lab.

I removed the 50/50 beam pslitter infront of the RF LSC diode, so now ~30 mW of power is incident. In addition in optimised the HWP infront of the PM to reduce the AM, 2f_sb = < -80dB.

The few irises in the beam path are closed down, I looked with the viewer and reduced the iris so it was just not clipping.

I didn't find a low enough ND filter to o the paracitic interfernce hunt.

The cavity locks stable with a UGF ~300kHz, the settings are

The Laser temperature on the controller displays: T+40.991, the slow output (T-ed to the laser slow input and the oscilloscope) is at -620 mV.

Once we get the cavity locked again we can see if we gained anything.

I put the boost filters back in FM10 of the ISO filter bank on BSC6 and BSC8. They switch when crossing zero but I have changed the tolerance (300 to 50 counts) and the time out (2s to 20s).

Jeff K. , Thomas V.

Below are the calibration parameters for the H2 ITMY Optical Lever:
        Slope          Y-intercept
Pitch [ 580.41229822  -11.51774017]
Yaw  [ 689.70532274  -13.3345144 ]


And here are the calibration parameters for the H2 ETMY Optical Lever:
         Slope           Y-intercept 
Pitch [ 1666.80728788   -33.14694715]
Yaw  [ 1727.67131855     23.41350328]

Both sets of calibrations were attained via the same process of moving the QPD along a translation stage and measuring the output signal.  All four sets of slopes are in units of radian*meters.