Work permits were signed and filed after morning meeting. The cleanroom from BSC3 was moved to BSC2, the East Bay cleanroom was moved over HAM4 and then both chambers were cleaned. The viewports and feedthroughs were removed from HAM4 north door and the north door was removed from the chamber. The plan is enter at HAM4 ASAP tomorrow and get the sampling done on the BSC1 Elliptical Baffle and then de-install it. Then we'll install dust barriers and remove BSC2's dome so that the SEI stack can be removed before lunch tomorrow.
Both the main beam path as well as the HWS path was aligned. Though the centering on each optics is not necessarily perfect, everything is far from clipping and I call it good enough.
Picomotors for the green injection were swapped with modified units to prevent the "stop ring"s on the tip of picomotors from interfering with Siskiyou mounts. To be exact, one spare pair was modified and replaced the one on the TMS table. Another pair that was on the TMS table was pulled out, modified and put in place.
We originally modified two spares, but have found that one modified picomotor was broken. This is the one which was on the table in the EY lab, and it's not clear to me if the modification broke it or if it was already broken.
Anyway, the injection picos work flawlessly now. We haven't done this modification to the red picos.
The returning beams look ugly, and it's difficult to say what is responsible for what. A part of it should be the ugly beam injected (we'll look into it later). But it's also possible that a part of it is coming from not-that-perfect TMS telescope alignment, i.e. the TMS telescope might be tilted in relation to ETM and we're compensating for the tilt using the alignment of the ALS table. This is not a big deal for the one arm test, though, and is good enough for start injecting green beam to the arm. We won't delay the installation because of this. (But we need to analyze the injected beam as well as the returning beams, which can be done without going into the chamber.)
We were initially running the old H2 IO Chassis for the H1 PSL. However we found two ADC channels had large DC offsets (in the first and third ADCs) and the duotone had bleed-through into the adjacent channel. We re-ordered and re-seated the cards, but the problem did not change. We then installed the H1 PSL Chassis and the problem was resolved. We will run the old H2 IO Chassis on a test system to determine if the problem was caused by bad ADC cards.
While working in BSC6, I looked at the two high quality viewports on the South door. I found that both have cleanliness issues, on the inside surface, that are consistent with failed cleaning practices. On the South door, the East viewport has a line that is about 4 inches long, and is in a shape that is consistent with a smear from a solvent being allowed to dry on the surface. The West viewport has approximately 10 droplets, with some up to 2 mm in diameter, that are consistent with water/soap droplets being allowed to dry on the surface. Next week, the history and inspection reports for these viewports need to be reviewed, and possibly a plan made, to try and clean them in-situ. Pictures are attached.
Betsy and I have done a little investigating this morning. Nominally, the life cycle of a custom viewport looks something like this: Incoming inspection (Condition-dark background, bright light, looking for gouges/dings etc) Cleaning (We're on about the sixth version of the viewport cleaning procedure at this point so we'll check and try to determine just how these viewports were cleaned. Some possibilities: Liquinox with bake, methanol with bake, freon without a bake) Assembly (Very possible for stuff to be deposited during this phase.) Post-cleaning inspection/proofing (QA process-Worth a check to see how process takes place and whether/how the process may contribute to the particulate load and whether there is anything that may cause spotting. Nominally, the testing set up is Class B.) Installation (There is always the possibility that IPA was used during the install to aid bolt torquing.) There are a few things we can try for clean-up: First Contact, methanol drag wipe, freon drag wipe.
Today Patrick and I made some good progress on interfacing the H2 ISC slow controls with the greater IFO controls.
I have created a global name space structure library that will be our interface to the TwinCAT/Beckhoff/OPC system. This library, Ifo.lib, will be imported by every PLC. It's leaf nodes are the variables that are written to and read by the PLCs, and will be translated into EPICs records.
We fleshed out the ISC PLC that will be run on the H2ECATY1 slow front end chassis: PLC1.pro. It imports the Ifo.lib library and defines a single global variable:
H2: IfoStruct; (*~ OPC:1 *)
The PLC executes three tasks, one for each of the attached slow chassis:
These three program tasks execute the various functions blocks that are the interfaces to the attached hardware modules, and the IN_OUT variables for those function blocks are elements of the global Ifo structure. For instance:
PROGRAM ISC_Common_Chassis
VAR
Vco: LowNoiseVcoFB;
VcoIn AT %I*: LowNoiseVcoInStruct;
VcoOut AT %Q*: LowNoiseVcoOutStruct;
END_VAR
Vco(
LowNoiseVcoIn := VcoIn,
LowNoiseVcoOut => VcoOut,
LowNoiseVco := H2.Isc.Als.Ey.VCO);
The global variable H2.Isc.Als.Ey.VCO... is exported as an OPC variable, is in turn exported as EPICS record H2:ISC-ALS_EY_VCO...
We managed to get some test variables talking to hardware, exported as OPC variables, and showing up as EPICS records that were accessible from CDS workstations.
All new code was committed to the "slowcontrols" SVN.
There's still a lot more fleshing out to be done, both for Ifo.lib, and the ISC PLC1 for H2ECATY1, but I think we have a path forward (pending approval from Daniel).
I will continue to work on documentation, particularly the library document for Ifo.lib. It would also be really nice to have a block diagram that describes in more detail the hardware/software interface, for reference.
Attached are plots of dust counts > .5 microns.
After the replacement of the PSL DCU (we had moved the H2 DCU over to serve as H1 DCU but found a channel on two of the ADC cards, hence the DCU build for H1 was installed) the loop-back tests were redone.
The H1 input mode cleaner volume (HAM1, HAM2, and HAM3) is ready for pump-down and leak testing. The blanked-off septum plate between HAM3 and the spool which connects HAM3 to BSC2 (which will experience the pressure difference) is fully restrained as the spool bellows and the HAM flange bellows are prevented from elongating or compressing via tie-rods. If this detail were overlooked, the HAM flange bellows would become fully compressed and likely damaged with the HAM3 side under vacuum and the BSC2 side vented. The 8" gate valve+turbo combination that had been mounted on eLIGO HAM6 was moved to the west door of HAM2 as a temporary means to pump this volume and will be removed later. The nominal turbo mounted atop HAM1 could not be used as its controller cable was too short (longer one to be ordered). Pumping was not begun as I am leaving soon and the roughing portion (pumping with only scroll pump) ought be monitored periodically so that adjustments can be made to the isolation valve set-point as the volume's pressure falls. I will send Gerardo the details such that he can pump during the day while he is here next week.
I measured magnetic fields from the new PSL chillers because pulsed heater circuits are often used in chillers and can produce large magnetic fields. The temperature is controlled by varying the duty cycle of an on-off square wave with a period of a couple of Hz, which may result in side band combs around the 60Hz peak in DARM. It turns out that there are two magnetic field frequencies associated with the new PSL chiller, 1.1 Hz and 1.4 Hz, which is expected because there are two chilled water circuits. The magnetic fields are comparable for each circuit. The lower plot in the figure shows a magnetometer spectrum when the 1.1 Hz field dominated, with a large peak at 1.1 Hz, and a 1.1 Hz comb around 60 Hz. The upper plot was made at a more distant location when the 1.4 Hz circuit dominated; 1.4 Hz side bands are just barely visible. In the ½ hour I monitored, the fields did not exceed about 1/10th of the size of the fields from the Neslab chiller that we had problems with in S5 (for the far location, where the side bands are at 5e-12 T/sqrt(Hz), the Neslab peaks would have been about 1e-10T/sqrt(Hz), and for the close location, they would have been about 5e-8T/sqrt(Hz) where the PSL chiller was at about 5e-9T/sqrt(Hz).
I expect that the magnetic fields produced by the PSL chiller to be less than a few times background at HAM6 (large tip tilt magnets) so it is probably OK, but, just in case, we should keep our eyes open for 1.1 and 1.4 Hz sidebands.
(corey, eric, hugh)
HAMISI#5
Took some photos of the recently-received Horizontal GS13s. These were placed on the #5 Optics Table, and Hugo ran some quick transfer functions to check their acceptance (heard they are good). Attached two photos of the set up.
It was decided that the bad Horiz GS13s installed on #5 will be pulled and swapped with (3) Horiz we just received. The three we pulled are== Horiz GS13s: 20, 37, 84. They are bagged & tagged and ready to be sent to LLO.
REMEMBER: we need to get Horiz Actuator & V1-GS13 serial numbers. Also need to install Particle Fences (if possible).
HAMISI#6
Finished up some minor tasks on this guy (Pull Downs removed, Mid Flexure Doors installed, Particle Fences installed).
J. Garcia, J. Kissel After seeing the recent good results from H2 SUS ITMY (further log comparing with previous measurements pending from Garcia, upon which we can "approve" the SUS for close out assuming no other mechanical changes), I asked the question: where did we leave off H2 SUS FMY? After not finding any recent aLOGs, but recalling that measurements were taken, I scoured the SusSVN and found two unprocessed data sets taken on 2012-05-01 and 2012-05-02. The results comparing these data with previous data show (assuming that no other changes have been made to it since those dates) that H2 SUS FMY is still rubbing. The 2012-05-01 data set looks identical to the 2012-03-14, post-fiber break initial check out measurement, which shows the rubbing, and the 2012-05-02 data set appears to have suffered from some sort of data corruption and or watchdog trip.
Retested Cable ISC-BSC6-1. Issue still exists on pins 19 and 18. All other sets on this cable show a forward voltage drop around 0.429V for the diodes. Below is a list of the pins I tested that passed. Pin 19 and 17 Pin 19 and 5 Pin 19 and 4 Pin 16 and 15 Pin 16 and 14 Pin 16 and 2 Pin 16 and 1
H2 SUS ITMY M0 & R0 transfer functions for the night of 05/10/2012. Initial analysis of the results look very promising for a BSC 8 chamber close-out. Final decision for a door-close on BSC 8 from the SUS team to follow.
While hunting for the source of the rubbing leading up to these measurements, it was found that the OSEM cabling leaving the top of the top mass had sagged and was contacting the tablecloth. I pulled some of the slack out of this cable through the clamp on the upper structure reducing the possibility of it rubbing in the future. Also, during this work, it was noted that the M0 BOSEMs were showing a lot of cross coupling between DOFs. I recentered all of the top BOSEMs on the main chain, and Garcia confirmed that this seemed to have reduced the coupling.
Progress on the VBO A leak test retrofit has been going well. I made a bit of an oversight and had to replace the HPS 903 vacuum gauge with an HPS 431 vacuum gauge to go with the existing controller. The SRS RGA software continues to be a pain, I updated it to version 3.2. The update from 3.0 to 3.2 required updating to .NET 2 which required .NET 1 which required updating to Windows 2000 SP5 (unofficial) which required an update to Windows 2000 SP4 (official), I feel like the old lady who swallowed a fly. The SRS software is still a pain though. Tested out the cold trap, one can see on the attached graphs (first one is after 15 minutes, second is after 150 minutes) the water vapor load is fairly heavy and will most likely only improve with a bakeout. Most likely there are "wet" parts upstream of the cold trap. After 6 hours of pump-down the system was holding steady at 7.2e-8 torr. A quick leak check found no grievous leaks, although a more thorough check wouldn't hurt before wrapping it up with heat tape. The LN2 cold trap won't be cold enough to significantly pump down on Argon so I should also work on fashioning a bag to sit over the Viton seal (since air and more importantly Argon seems to permeate at a slow rate) and create a Nitrogen shield.
We had a timing glitch at EY yesterday afternoon. All front ends except for SUS were restarted yesterday (SUS was in use by in-chamber staff), I have just restarted the SUS front end to complete the set. Thurs afternoon h2nds0 crashed, the console was frozen at a dmesg display. I had to reset the computer to recover. We don't know the reason for this crash.
The assembly validation testing report for HAM-ISI Unit #5 is posted under the DCC for validation.
Reports regading the previous units tested/validated (Phase I) at LHO are also available on the DCC:
HAM-ISI Unit #1
HAM-ISI Unit #2
HAM-ISI Unit #3
HAM-ISI Unit #4
This report was validated today. However..
This unit was tested with non-production horizontal GS13s on. We just received a crate of production horizontal GS13s that were just tested and work.
We decided to install the production pods we just received on this Unit. All the tests involving GS13s will be redone. If no pod fails during/after installation, this unit will be our second unit after Unit#4 (HAM2) to be equiped with a full set of production pods, offering us another occasion to reduce the time needed for the chamber-side testing.
Picomotor modification picture: https://ligoimages.mit.edu/filestore/1/9/3/2/0_bd6d89c33a325dd/19320scr_3faebab47e425a5.jpg?v=2012-05-10+21%3A24%3A09
Left is stock, right is after modification. We modified both in the end.
BTW, we needed to tilt the TMS in PIT for some non-negligible amount. So much for initial alignment under the test end.
We had to move 50-gram weight because the OSEM offset didn't do it. After finer alignment, 50-gram weight is positioned to relieve the OSEM offset in PIT.