Turning down the output power to 100 mW.
Install control converter for Lighthouse dust monitors.
Work finished at 9:30 AM PT.
Hugh, Hugo,
Input filters and matrices were implemented on HEPI-ITMX yesterday.
Today we used the TF measured on 01/02/14 to design its symmetrization filters, which we installed and turned on. We also installed the position blends (IPS=0, L4C=1)
We then deisgned most of the position loops for this unit, until we got stuck on a scripting issue that took most of our evening: we cannot plot our position loops for the following DOF: Y,RZ,HP.
Since the scripts we use are generic, we suppose that they are fine. We suspect that the data we use may be corrupted. Indeed, the TF data had to be re-processed after collection, to account for in-field mis-wiring, and it is possible that the re-processing was enough for plotting in the local basis, but caused further problems down the line whith the position loops design scripts.
Loops are designed for every degree of freedom, but could only be looked at along: X,RX,RY,Z,VP
Next step is either to try to arranging the data, or take a new set of TF.
Meanwhile, we reverted all the scripts that we modified locally in our atempt to debug.
I am leaving a transfer function measurement running on BS and PRM overnight. The PRM measurement needs the IMC to stay locked. Please try not to unlock the IMC.
Finished. IMC can be unlocked.
Hugo, Sheila
Having heard that at Livinstgon ISC is seeing about one fringe per second (need to confirm this is for green, not infared) (also see LLO alog 10404), while here we see more like 10 fringes per second with the green, we wanted to investigate the motion of the optics. Laser frequency noise is something that should also be ruled out, although it seems unlikely since the frequency of the motion we see is around (roughly) 0.1Hz. We wanted to compare the SEI/ SUS platform motion between the two sites. To do so, we compared thefollowing:
... Along X (Longitudial) and RY (pitch).
The SUS and SEI plots (which were not calibrated) would suggest that the magnitude of the motion recorded on both SUS and ISI is 10x bigger at LHO along X (longitudinal) while it was recorded within the same range along RY (Pitch).
We thought that differences in ground motion could explain this observation. Ground motion (LLO,LHO) was however comaprable between sites, at the time of the measurement.
Another explanation could have been a difference in matrices/calibrations between sites, but, as far as the ISI are concerned, they seem to match.
We see that we loose lock often because we use up the VCO range. The VCO full range is 2 MHz (awiki) which is equivalent to 14um peak to peak change in the arm length.
Another usefull comparison to make would be to look at the data from the ISIs durring HIFO Y to see if the motion that we had then was comparable to what we have now.
The X arm is left overnight trying to lock, with automation. The channel H1:ALS-X_REFL_LOCK_STATUS will try to report when the cavity is locked, although it should be double checked with either ALS-C_COMM_LF or ALS-C-TRX_A_DC because the threshold probably needs tuning.
We were able to lock the X arm stably (for several minutes with no offloading) the first time we "locked" it. At that time our alingment was far off, and we weren't really locking a real cavity mode (alog 9127). Right now we cannot lock for more than about 30 seconds, more often the locks last only a second or 2. While it seems most likely the lock was stable then because of our terrible alingment, I just wanted to check that we haven't had a change in the motion of the optics since that time. Attached are three screenshots from Jan 7th (the night after that lock, for which data is available) and last night. As expected, the motion is either the same or reduced since then by the work that SEI has been doing.
Livingston people report that they are seeing about 1 fringe per second with the green, that is much less motion than we have (here it is about 10 fringes per second). But the apparent stability from a week ago was not due to less motion, it must be some optical difference due to the bad alingment we had then.
ADC channels were adjusted in accordance to the latest version of the D1000298 system wiring in the following HAM-ISI models:
L4Cs were wired as well.
Models were re-compiled and restarted.
In-field tests were performed by Hugh and Mitch to confirm those changes.
Models were commited to the svn:
Work was performed uner WP#4396, which is now closed.
I updated the h1conlog channel list to use the names in /ligo/lho/data/conlog/h1/pvlist_1389919431. 19742 channels were added. 11118 channels were removed. The total number of channels is now 106321.
There are now approximately 59,019,605 rows in the database.
1. PMC monitor PD was T-ed and connected to PSL spare 7 cable.
Since bogus power reporting of PMC transmission monitor has bothered us more than once (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9300), and since this might be an oscillation of the PD electronics, we T-ed the output of the PD and connected it to "spare 7" cable which goes out to the PSL rack outside.
I connected the cable to Ch.4 of the scope in PSL R2 rack.
When the power (H1:PSL-PWR_PMC_TRANS_OUTPUT) is reported 11.2W, the PD output was measured to be 715mV DC on the scope, with AC RMS of 1.74mV without any noticable oscillation (attached is the scope screen with AC coupling). Next time it is reporting bogus power you should go to the rack and see how it looks.
2. IO Kentec beam dump
We have found two IO Ketek beam dumps, both 0.75" aperture variety (ABD-3/4), in the cabinet in the PSL ante room. We took one that is to be installed in the HAM2 ceiling viewport in preparation of the 10W operation.
This beam dump is to replace a black glass that is in place now. Ultimately Kentek will be replaced by the final solution once it is manufactured.
We will NOT remove Lexan cover for this viewport until approved by John Worden.
A bigger Kentek (2" aperture, ABD-2) was already installed in IOT2L some time ago. This will be left in place as it's considerably bigger than 0.75" one and thus will run cooler. The final solution will come later than the HAM2 ceiling one, but it will come at some stage.
Mitchell & I departed the LVEA ~1650pst
With the model changes Hugo did for the ISI we were able to confirm all the sensors we have installed. Haven't run Spectra but the look reasonable for now. We dressed & secured cables, installed cable brackets and took a stab a preliminary balancing.
To do--Install Table extension (Or should we test w & w/o?)
Fine tune balance, float HEPI & level locked ISI--it already is pretty close, only 27mils tilt across the table. Revisit balance, maybe adjust lockers.
Validate ISI.
IAS
We are investigating startup problems observed with the HWWD units under test. As part of the testing we power cycled the unit in the CER twice this afternoon. This unit is monitoring ITMY only.
Attached below are power spectra of ETMX main chain OSEM and optical lever signals from Monday January 13, 2014 through Thursday January 16, 2014. The magnitude of all signals has decreased by about a factor of 100 since Monday.
On the PUM stage of the ETMX, the upper left OSEM is noisier than its counterparts as can be seen from the ambient noise figures. It's possible that this OSEM signal is not being correctly filtered, or there may be a problem with the OSEM itself (cabling, led, or photodiode, etc). This isn't a huge problem that we have to fix but is worth noting while we are undergoing ER5. Also attached is a coherence plot between L2 stage OSEMs and optical lever pitch and yaw. The sensors are highly coherent near the suspension resonance peaks, but are pretty incoherent after about 2.5 Hz. The problematic upper left OSEM is less coherent with optical lever pitch and yaw, which again suggests that this sensor has some electronic issue.
::: EX is Laser HAZARD ::: LVEA is Laser SAFE ::: EY is Laser SAFE ::
EY: Travis doing Welding clean-up & possible Quad work (probably most of the day)
Dust: Dust #9: Calibrate failure (notified Patrick)
PSL: Went through PSL Checklist. Have a "check diode chiller" WARNING & sent an email to the PSL group email. Doug filled it up around 11:30am
Day's General Activities:
We reattached the ETMy upper structure to the ISI on the cartridge test stand this afternoon. We have a few more dog clamps to attach but can do those anytime. SEI can get to work there tomorrow if they see fit. We'll work elsewhere.
Kiwamu with remote help from Cheryl
As a part of the high power prep, I did three things this morning:
Stray light:
I looked around the inside of the IOT2L and ISCT1 enclosures with an IR viewer to look for a stray light which needs to be properly dumped. I did not find a stray beam and therefore I didn't have to newly install a dump.
Power budget:
See the attached. When I made the measurement on IOT2L, I intentionally misaligned MC2 in order to have high and stable laser power on the IOT2L. As for ISCT1, I misaligned PR2 to avoid a fringe while maintaining the PRM reflection. Note that the IMC incident has been 1 W (see alog 9306) these days and during these measurements. Because the POP beam was so dark, I didn't even attempt to measure the power. Instead, I made a back-of-envelope estimation of the maximum power in the POP path with an assumption that the power recycled Michelson is locked.
Power at POPAIR_A (or POPAIR_B) = (1 W incident on PRM ) x (60 power recycling gain) x (250 ppm PR2's transmissivity) x (90% BS in HAM1) x (50% BS on ISCT1) = 6.75 mW
Of course, in reality, it must be smaller than this due to losses and etc.
Search for PRM parking beam:
Because we didn't check the parking beam during the last vent and also readjusted the alignment of the input optics recently, we need to find a good alignment for PRM again which gives us a parking beam coming out through the top view port of HAM2. Since a CCD camera was already mounted on the viewport, I used it to see if I can find the beam. I tried the good PRM biases (P=-330 and Y=-6100) that was established back in April (see alog 6168). Also, I enabled AWG and shook PRM in both pitch and yaw in order to somewhat expand the parameter region that I am scanning. However, I didn't find a beam or any sign of beam on the monitor. Also I turned the illuminator on and off to see if the CCD camera is actually looking at something useful, but the CCD kept showing a dark background regardless of the illuminator.
I am concluding that we need to remove the camera canister to see how the camera is doing and directly check the parking beam with a laser card or IR viewer.
Starting at 12:01pm.
Work completed on HAM4 at 12:30pm. Model was recompiled and restarted. Hugh and Mitch are now plugging the sensors in to check out the model wiring.
HAM5-ISI model modifications are on-going. h1isiham5.mdl will be restarted once changes are confirmed on HAM4-ISI. Models will then be commited to the SVN and WP will be closed.
