The B&K hammer testing is complete on the H2 SUS ETMY.
Staging work continued yesterday. Kyle vented the volume on Monday, so the Apollo crew broke bolts on the dome and the doors and installed a soft roof. The west (end) door was removed using the large engine hoist and then laid down on the north side of the beamtube. A soft cover was placed on the opening. One leg was removed from the E-module so that the engine hoist could be moved to the north side of the chamber (A very tight fit!). Once the hoist was in correct position, the leg was restored to its rightful place. Two chamber-side carts, BSC flooring, vertical dispenser of foil and CPStat were hauled from the corner to the end.
I pulled work permits for staging and ICC at HAM2. As soon as HAM2 has an initial wipe-down, the crew will start staging for entry.
Yesterday, the crew completed feedthrough install and returned one door to the chamber. This morning their first task is returning the east door to the chamber. Once that is done, HAM3 ICC will be closed-out.
Tuesday WD work.
We performed some more software watchdog tests briefly at EY before handing that system over to Jeff. Later we performed some WD trips on ITMY as we install an alarm system for the new watchdogs. ITMY switching will continue Wednesday as we complete the alarm system.
We are creating a new medm screen for the software watchdogs, accessible from the CDS part of the SITEMAP
Today, Gerardo and I glued the first metal prism to the ITMy (ETM02) using the new little template jig. So far, so good. Yesterday, Travis built up the metal Class A PUM and loaded it and the new wire loops into the lower suspension. We will glue the second metal prism tomorrow. We then need to finish the cleaning on the mass (TBD by CIT COC) before loading it into the loops in the suspension.
Attached are plots of dust counts > .5 microns.
There was an automated call to the Control Room today just before 1PM (PST) from Hanford informing us of siren/alarm testing ongoing this afternoon. The testing will continue intermittently until about 4PM today.
The attached are M0/R0 transfer function measurements on H2 SUS ETMY M0/R0 with the damping loops closed. Drive parameters were identical to the undamped measurements.
A late alog to cover the testing performed at LHO last week on the CDS software OSEM watchdog system, released as RTS version 2.5.
D.Barker, R. McCarthy, J. Batch
R.Bork, A. Ivanov
Further to my last ALOG, we performed more testing in the LVEA on ITMY and FMY (which WD Disables SEI BSC8 via Dolphin IPC). We then extended the tests to the EY end station, in which ETMY was tested (which WD disables SEI BSC6 via RFM IPC). We are in the process of formally writing up the test specs and the test results, but we can announce here that all tests passed with only one minor software change needed.
On Friday Jim and I returned all systems back to their nominal state, with the software watchdogs (which run on the front end IOP processes) running along-side the user SUS and SEI models. Jeff performed ETMY commissioning Thur and Friday and we can report that the new watchdogs do not trigger during nominal operation of the systems.
The new IOP OSEM watchdogs are monitoring the six M0 OSEMS on ITMY and ETMY, and the six M1 OSEMS of FMY, using the nominal trip filters and levels. Note that the TMSY OSEMS are not being monitored at this time because they are not in operational range and would trip the h2iopsusb6 watchdogs if attached.
I'll alog links to the relevant DCC documents covering this work when they are released.
The crew got through wipe-down on Friday so they will start this morning with the second vacuum followed by FTIR samples and final inspection. Feedthroughs are inspected and ready for installation ASAP. I would prefer to get that done before we move the cleanroom.
Thomas and I cleaned the BSC8 RH. It did have some large fiber debris under the NiCr wrapped glass form, sitting in the shield. This came out easily once we removed the RH from the quad structure. Smaller glass particulate was cleaned with swabs wetted with IPA, and an IPA flush around the macor parts. Full set of pictures: https://ligoimages.mit.edu/?c=1031 RH is reinstalled and ready to go.
Attached are plots of dust counts > .5 microns. I have also included a plot of H0:PEM-LVEA_DST15_MODE to show when the dust monitor located under the clean room over BSC8 (H0:PEM-LVEA_DST15_5) was not being recorded.
Apollo has been working on removing unnecessary items from the VEA at Y-end. I went out and checked yesterday morning and things looked good. Since the VEA was not in laser hazard this morning,Terry S. and I took the opportunity to walk-down the VEA to establish as time-line for the required cleaning. Terry and the crew are doing a deep clean today. As soon as SEI and SUS testing are complete, the testing cables can be removed from the lay-down space on the E-module and the precision cleaning can begin (~Monday,26 March). We'll try for second cleaning ~Tuesday, 27 March. Many items have been staged for the install including both soft roofs, all door and dome covers, and pallets for doors and dome. I'm attaching a drawing of the floor lay-out for BSC6 cartridge install so that everyone is aware the space restrictions we're dealing with.
Brushing is complete: a total of five drills were used in this chamber. First vacuum has started. Hugh brought the HAM spacer to the crew for fit check and mark up as soon as first vacuum is completed. Once that is done, we'll proceed with wipe down, second vacuum and close-out. I anticipate we will be finished with cleaning by COB today and installation of feedthroughs can start on Monday.
Yesterday I found the diode room AC unit without power, and according to trends it had been down since 3/5. The electrical box outside the LVEA, near the outdoor units, was off and the pull tab (gives units power) was found ~10 feet away. This occured during a high wind storm, so it's possible a strong gust of wind threw something at the box. With everything back in place, the room cooled down from 86F to 70F in about an hour. The diodes do not seem to have been affected by this.
The environmental monitoring system is currently down, which is why the diode room temperature has dropped to zero.
Water pipe is being laid out for the chiller lines. Work will be ongoing through this week and next week.
J. Kissel, R. Quitzo-James In all suspension TOP to TOP transfer functions that we've taken to high frequency (i.e. > 10 Hz), we have found a confusing turn up to a slope of ~f^(1), where we expect the slope to continue to drop off as f^(-2). At the advise of one P. Fritschel, we've taken M1 to M1, OSEM basis, transfer functions of H2SUSFMY both locked and unlocked to try and explain, if not at least identify, the source of this turn up. As Peter suspected, the locked spectra show the same turn up at high frequency. Aside from the mechanical resonances left in the transfer function, this implies that there is some fundamental coupling between the OSEM Coil drive and PD sensor. It has been suggested that this coupling may arise from coil current drive mixing the PD sensing current, either at the OSEM head, or some where along the electronics chain, as these signals are on the same cable. Note, this is not necessarily of great concern, given that we use these TOP BOSEMs for local damping between ~0.1 and 10 Hz, and perhaps for low frequency ISC offloading; all control authority will be rolled off aggressively by 10 Hz. These transfer functions are taken with basically the maximum amount of current going through the coils (to get the best SNR for the measurement), so with the fast roll off of control authority above 10 Hz, I expect this noise source will be negligible. Attached are two sets of plots: 2011-11-15_H2SUSFMY_hfturnup_M1TFs.pdf -- The collection of M1 to M1, OSEM basis, H2SUSFMY transfer functions comparing the measured, suspended transfer function (GREEN) against a model of that transfer function (CYAN) composed of the production, suspended model transfer function (RED) plus the locked transfer function (BLUE). The model agrees very well with measurement, aside from some scaling factors in the F1, F2, and F3 sensors. (Details below -- **). 2011-11-15_H2SUSFMY_hfturnup_currentcoupling.pdf -- IF the mechanism is sensing current mixing with drive current, this plot shows the locked transfer functions for each degree of freedom calibrated into PD Sensing Current per Coil Drive Current. The calibration assumes the same [m/N] calibration that is always used to scale measurements (a factor of 60 for aLIGO production electronics), and then converted to current assuming a force coefficient of a 10x10mm magnet with a BOSEM coil -- 1.694 [N/A] (see T1000164), and displacement sensitivity of 62.5e-2 [A/m] (see T1100479, or T0900496). --------------------- Details ** --------------------- The production matlab models of the aLIGO suspensions are in the EULER basis, so it took a little bit of math to get the model suspended transfer function into the OSEM basis. The math is as follows: Assume the model, euler basis, mechanical transfer function is a 6 x 6 matrix, Pe. Hence, the 6x1, euler basis, response vector VRe, is related to the 6x1, euler basis, drive vector VDe, by VRe = Pe VDe (1) However, we can decompose the euler basis drive and response vectors into their respective OSEM basis, using the known OSEM2EUL, oMe, and EUL2OSEM, eMo matrices: VRe = oMe VRo (2) VDo = eMo VDe => VDe = (eMo)-1 VDo (3) which means, that we can solve Eq. (1) for the OSEM basis transfer function, VRe = Pe VDe oMe VRo = Pe (eMo)-1 VDo VRo = (oMe)-1 Pe (eMo)-1 VDo (4) Now, this would be easy to do in matlab, IF the Pe matrix was a 2D matrix, like the OSEM2 EUL and EUL2OSEM matrices, but because Pe is a 3D matrix, response x drive x frequency, I had to do the matrix multiplication "by hand," i.e. [ Pe (eMo)-1 ](i,j,f) = Σn Pe(i,n,f) (eMo)-1(n,j) [(oMe)-1 Pe (eMo)-1](i,j,f) = Σm (oMe)-1(i,m) [ Pe (eMo)-1 ](m,j,f) This conversion of the model, i.e. exercise of brute-force math, seems have done awesomely at predicting the < 10 Hz frequency response and DC scaling of the transfer function for LF, RT, and SD, especially after including the normalization factors that are present for each OSEMINF gain to account for the OSEMs sensitivity variations. However, I'm still missing a factor of ~1.5 for the three FACE sensors that I can't figure out from where it comes. I'm not gunna bang my head against the wall about it -- the point of the measurements has been made! -------------- Data / Analysis -------------- Raw Data: ${SusSVN}/sus/trunk/BSFM/H2/FMY/SAGM1/Data/111115_H2SUSFMY_WhiteNoise_??_0p1to900Hz_bsfm*locked.xml Exported Data: ${SusSVN}/sus/trunk/BSFM/H2/FMY/SAGM1/Data/111115_H2SUSFMY_WhiteNoise_??_0p1to900Hz_bsfm*locked_tf.txt Analysis: ${SusSVN}/sus/trunk/BSFM/H2/FMY/SAGM1/Scripts/analyze_111115_H2SUSFMY_M1_lockedvsunlocked.m
I'll provide visual evidence some time in the future, but we've now seen after installing FMY in chamber, where production electronics and properly shielded, twisted pair cabling is used, we no longer see this high-frequency turn up.
