Nic, Evan
We went down to EY to see what was up with the green WFS on ISCTEY (D1400241). To start with, we decided to resteer the beams so that they are not clipping on any optics.
We also tightened down PD4, which had some issues with loose mounting.
Jeff B and crew (Andres, Mitchell, Joe D, Chris S) and grounding plugs to and loaded eight of the nine HXTS and the OMC into the modified HAM ISI storage container this morning. The work went more quickly than we estimated.
All the suspensions loaded thus far looked very good after their couple of years in the wine barrels. All magnets are still in place, no "rust" was noted on the blades or wires, no masses have shifted on their stops, and no wires have broken. There was no visible contamination on any of the suspension parts. Particle counts taken before, during, and after the work show <100 counts of 0.3 micron particles and less for larger particle sizes.
Upon taking a look at all large suspensions and small suspensions aux channels only ETMY stage L1 was found to have a noise aux channel which is showing some possible issue. ie ~ -4300 cts. This is showing on "noise" (4), volt (UL) and fast_I (LR). I have begun setting up DTT templates for all aux sus channels to further examine questionable readings.
E. Merilh, J. Kissel This investigation concludes that the issue identified in LHO aLOG 14922 is not as pervasive as originally thought. *phew*! The DTT templates to which Ed refers will assess the noise performance of these channels. We'll work on resurrecting Koji's automatic SUS AUX channel characterization suite, found here: /ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/MatlabTools/ezQuadDewhitening This will assess whether each of the monitor boards show the expect driver's driven transfer function after install.
Removed these channels until Beckhoff issue is resolved.
The dmtviewer process on projector0 had used up all available memory on projector0 and had quit running. I rebooted the computer and restarted the dmtviewer shortly after 9 AM this morning.
Laser Status: SysStat is good Output power is 33.3 W (should be around 30 W) FRONTEND WATCHdog is Active HPO WATCH is RED PMC: It has been locked 13 day, 1 hr 26 minutes (should be days/weeks) Reflected power is 2.0 Watts and PowerSum = 25.8 Watts. (Reflected Power should be <= 10% of PowerSum) FSS: It has been locked for 3 days, 21 h and 33 min (should be days/weeks) Threshold on transmitted photo-detector PD = 2.265V (should be 0.9V) ISS: The diffracted power is around 7.4% (should be 5-15%) Last saturation event was 3 days, 21 h and 38 minutes ago (should be days/weeks)
David B., Jim B., Patrick T. We looked at H1:ALS-Y_REFL_SERVO_IN1EN from '00:00:00 Nov 2 PDT' to '03:00:00 Nov 2 PST'. The correct behavior is observed: ... 11/02/2014 01:59:59.005479920 PDT Off NO_ALARM NO_ALARM 11/02/2014 01:59:59.055615806 PDT On NO_ALARM NO_ALARM 11/02/2014 01:00:01.060458106 PST Off NO_ALARM NO_ALARM 11/02/2014 01:00:01.110599290 PST On NO_ALARM NO_ALARM ... Note that PDT and PST should be specified for searches covering times of the changeover.
Here is the list of commissioning task for the next 7-14 days:
Locking team:
Modecleaner team:
Alignment team:
RF:
The question of whether Operators have been checking the Observation Intent button came up this morning (basically we have). I was curious to see how much this button is being used and how quick Operators are to Unclick it at the beginning of our shifts.
I went ahead and trended/Conlog-ed the channel (H1:ODC-GRD_OPERATOR_OBSERVATION_READY). Attached is a trend of the channel over the last 60 days. Over this time we've had (6) "Undisturbed" segments (only counting segments over 30min):
In all of these instances, the Button was taken to "Commissioning" within the first few minutes-hour of the Operator shift.
Note for Operators:
Note On Overnight Measurements & Request To Limit Early Morning Access (i.e. Cleaning)
With Operator shfits starting at 8am, there can be instances when the cleaning crew can enter the VEAs when we are in an "Undisturbed" Observation Intent state. Now if there is ever a need to limit cleaning activity due to overnight measurements: please send an email to Jodi and/or Christina so they have a heads up for the cleaning team. Otherwise, one can do what was suggested by Ed M. in his alog last week (i.e. post signs on doors requesting to postpone cleaning in the morning).
I manually added H1:LSC-PD_DOF_MTRX_LOAD_MATRIX to Conlog. The script that generates the channel list needs to be modified to add this channel. Otherwise if a new channel list is generated by the script and used, this channel will be removed. I will plan to make the change to the script on Tuesday as part of maintenance.
This morning ISS diff power was at ~11.6%. REFSIGNAL was @ -2.02V. I adjusted REFSIGNAL to -2.11. diff power is currenly at ~7%.
Attached is ten days of minute trends for some channels at EndX and EndY for the HEPI Pump systems.
At EndX, the Pump is still controlled(Ch2) by the last pressure sensor on the Pump Station skid(Ch1.) At EndY, the control was switched early Thursday to the actual differential pressure across the actuators measured in the VEA (Ch5.) On Friday, you can see where I smoothed the Supply & Return pressures and the Max/Mins of the differential pressure and the subsequent drive to the Pump Motor. It looks like the diurnal temperature fluctuations are increased significantly when the daily fluctuations or the daily minimum exceed some threshold.
We still have room to improve the grounds noise but I don't believe there is any reason not to switch all the Pump Stations to the differential control.
no restarts reported
model restarts logged for Sat 08/Nov/2014
2014_11_08 00:27 h1fw1
2014_11_08 17:29 h1fw1
both unexpected restarts.
Nic, Evan
We have gotten DRMI to lock on the 3f signals using the new, modified BBPD serving as REFLAIR_B.
Some good UTC times for 3f locking: 2014-11-09 0:56:50, 01:13:10, 02:41:00
Judging by POPAIR_B_RF18_I_ERR, the lock is kind of ratty both on 1f and 3f.
I think the reason Alexa and I couldn't lock yesterday is that we had the wrong relative gain for RF135Q/RF45Q. Nic and I remeasured it today and got 2.0. It is still true, however, that the ramping matrix doesn't give the expected behavior; it seeems to approach the requested value almost asymptotically, taking far longer than the specified ramp time.
We then adjusted the gains in the 3f input matrix to reduce gain peaking in the demodulated spectra of RF27 and RF135. We have written the following matrix elements into the lscparams guardian file:
Attached are our measured OLTFs of PRCL, MICH, and SRCL while locked on 3f. The DTT files are in my directory under Public/2014/11/DRMI3f
.
model restarts logged for Fri 07/Nov/2014
2014_11_07 06:28 h1fw1
unexpected restart of h1fw1, first one since Monday.
Alexa, Daniel, Evan
In order to use the new REFLAIR_B, we have made the following changes:
PRCL | SRCL | MICH | |
RF27I/RF9I | −0.49 | −3.9 | |
RF135I/RF45I | 2.4 | ||
RF135Q/RF45Q |
|
The RF27I/RF9I measurement for SRCL is low SNR for some reason. [Edit, 2014-11-05: I think I must have taken the RF135Q/RF45Q measurement upside-down. I retook it today and got a magnitude of 2.0.]
By using these gain measurements to adjust the DRMI 1f matrix elements, we have tried to transition from DRMI 1f to DRMI 3f. Howver, so far it keeps dropping lock.
The demodulated 1f and 3f spectra (taken while DRMI is 1f locked) are attached (units are cts/rtHz).
Something funny is going on with the LSC_INPUT_MATRIX. The ramping is not correct, plus it loads without the user request (and it's not the guardian)...
I was almost able to transition PRCL from 1f to 3f with a ramp of 10 and gain of -6.0 in the 3f signal, but it started to mode hop and lost lock. We probably should have touched-up alignment before trying to transition.
(Keita Daniel)
A spare BBPD with serial number S1200247 has been modified by removing and bypassing U1, the first RF amplifier stage. The attached BBPD_tf1.pdf file shows the transfer function before and after. Plot tf2 shows the ratio.
We took a baseline intermodulation product measurement by sending a two tone signal into the AM laser. The first tone was at 45 MHz and generated a line with -15 dBm amplitude. The second tone was a 90 MHz line also at -15 dBm. Plot IP2.png shows IP2 and IP3 lines at 135 MHz and 180 MHz with amplitudes of -57 dBm and -60 dBm, respectively.
The plot labeled IP2M shows the same measurement after the removal of U1. Close-in plots IP2M135 and IP2M180 show spectra with lower resolution bandwidth. The intermodulation lines are visible at a level around -115 dBm. One might consider this an upper limit, since the dominant distortion could be in the AM laser head. The IP2M135A plots shows one of the lines moved by 100 Hz. This now separates IP2 (lower frequency) and IP3 lines.
Finally, the IP2Mplus plot includes 20 dB higher drive levels to bring the lines back to -15 dBm. The 135 MHz lines shows up at -90 dBm which seems puzzeling low compared to the above measurement.
Modification pictures.
At Caltech, optical tests for a BBPD unit with the equivalent modification was done.
27MHz: Transimpedance 226Ohm, Shot noise intercept current 0.63mA
135MHz: Transimpedance 98.5Ohm, Shot noise interept current 3.8mA
These numbers are as expected.
In the attachments the following results are found:
- Schematic diagram
- Transimpedance (0.1-500MHz)
- Current noise level
- Transimpedance/Shot noise intercept current measurement with incandescent light at 27MHz and 135MHz
- IP2/IP3 measurement (same as before)
Somehow, aligning the beam on the Green LSC PD gave us a factor of 10 more power.
Attached, one may see the change in power on the green refl PD at end Y. The first shows just a few hours from today, showing the change in power.
Also attached is 2 weeks of trends, to see if the PD was well aligned in the past, and it was just bad this morning. As far as I can tell, the power from this morning was a common number measured by this diode. There are also times with the power larger, but the value is not stable. I'm not sure if this is when the arm is aligned. I will check once we again align the arm.
The WFS PZT centering servos were measured and tuned up. All DsOF have UGFs that equal to roughly 10Hz.