EndX Xend EX ETMX BSC9 HEPI Locked on Stops

WP 7364 -- Locked EndX HEPI this morning, pretty close to operating position, Z not so much.  Will leave this WP open until the HEPI is unlocked.

ETMX found in ISI DAMPED HEPI OFFLINE.  Took SEI guardian manager to DAMPED--this took the HEPI to Robust Isolated.  The HEPI was then locked onto its stops as closed to the Isolated position as possible: dX dY dRX dRY are all under 10um(urad), and dRZ is less than 200nrads. dZ is 83um but I figured this was the least significant dof for the upcoming task.  These di values are the difference from the nominal isolated position.  HEPIs for the BSC don't have a 'down' lock so it is difficult to keep it from squirting up as the sides are pinched into position.

Of note, when the ETMX Optical Lever was recentered on 15 Feb, it was done without the HEPI holding the nominal orientation.  Fortunately, Jim and I have debiased the HEPI position onto the DSCW springs and as you can see on the attached plot, the isolated/not isolated amounts to about 6 Oplev yaw plot units (urads?Yes urads).  Still, nominally, oplev centering should be done with the HEPI fully isolated (ISI not so important.)

The attached 3 hour plot has the HPI & SEI guardian states (chans 1 & 2), the OpLev Pit & Yaw (3 & 4), with the rest being the HEPI position residuals. Note the annotations showing the shift in the OpLev Yaw when the HEPI Isolates and the residuals go to zero.

DARM model in Python

Summary:
The core functionality of the Matlab DARM model has now been replicated in Python. Attached are figures in a single PDF file showing the primary results. By eye, these look reasonable. A more detailed study comparing to the Matlab model is forthcoming. I also replicated a study made for the L1 detector by Joe B. (see LLO aLOG 29622). I propose to call this code pyDARM.

Details:
I have ported most of the core functionality of the DARM model from Matlab into Python. So far, I have done spot checks by eye to make sure that the results look sensible. I have not yet done a detailed study comparing to the Matlab version, but will do so soon.

I have produced plots showing:
1) DARM digital filters
2) Sensing function
3) Actuation function
4) Open loop gain
5) Frequency dependent actuation authority of each stage compared to inverse sensing
6) Ratio of each stage to the overall calibration

As can be observed, the scale of each figure appears reasonable (comparing with, e.g., G1700316), the OLG is stable, and with a UGF with the correct value (by eye). The contribution of each suspension stage is closely matching L1's results using the Matlab model (see LLO aLOG 29622).

What was done:
- Write python version of Matlab functions to parse Foton filter files and to compute IOP downsampling filters from RCG code coefficients
- Exported numerical values of zeros, poles, gain, delay from analog AA and AI models (these are objects in .mat files)
- Exported ASCII file of the frequency response for the suspension force-to-length for each stage. This is read in and used in the python DARM model, and so far can only be at specific frequency points
- DARM filter bank digital filters computed, sensing function and actuation functions are computed from parameters
- Intermediary data products can be accessed
- Code structure is "flatter", meaning less jumps between different functions/files. Hopefully this makes the code more accessible and readable.

Required python modules (so far): scipy (e.g., filters), numpy (e.g., arrays/array math), collections (for namedtuples), matplotlib (for plotting)

Quirks found along the way:
- You can't directly multiply or add filter objects together in Python (the + and * functions are not overloaded in Python). I had to code up my own version to 1) add filters by using polynomials from roots, computing a transfer function filter, and then converting to a zpk object, all using scipy built-in functions; and 2) multiply filters by appending zeros together, poles together, and multiplying gain.
- The scipy sos2zpk() function is not exactly like Matlab's version. I found an extra zero and pole when converting because Matlab removes any zeros in the 3rd and 6th positions of an sos section before computing a filter from the sos coefficients

To do list (short term):
- More detailed study comparing Python with Matlab models
- Read in a config file
- Make an L1 model to check for any differences
- See if there is a way to read Matlab .mat file and objects therein. This didn't look trivial when I tried at first, which is why the analog AA and AI models were exported as well as the frequency response of each suspension stage
- Address how to get the force-to-length transfer function for each stage for arbitrary frequencies
- Add computations for GDS / DCS pipelines

Longer term:
- Hook this into a pipeline from measurement to model to uncertainty estimate pipeline

Attached is an updated figure to include the inverse sensing contribution ratio to the overall calibration. Observe that the inverse sensing has impact on the overall calibration above ~10 Hz.

CP4 turbo valved out

Valved out CP4 turbo around 10:30 am local for bake enclosure work nearby. Expect pressure at PT-245B to drift up.

PSL Mac mini

One of the PSL Enclosure's Mac minis is dead.  Its hard disc cannot be repaired.  The computer will be replaced in the near future.


Carlos / Peter

CP4 bake enclosure installation

The installation of CP4's bake enclosure started today. All parts were delivered and the uni-strut framing is ~1/3 installed. We will resume at 6:30am tomorrow I'll post some pictures tomorrow.

Turned on X-End Station Purge Air

This morning the purge air skid was turned on.  The dew point was measured at -33 ^oC after the drying towers cycled twice each.

ITMY R0 RT OSEM short - attempted fix at feedthru

After Kyle and Gerardo slow vented the corner, Gerardo and I pulled the 4.5" feed-thru for ITMY CABLE #7 and #8.  We then pulled both in-vacuum cables off the feed-thru in order to swap in a fresh copper gasket.  I re-tightened the back-shell screws and inspected cable #8 and then reseated it - it felt better going in that it came out so we had hope.  Running th spectra showed no improvement however.  We then tried to inspect the ~1ft of cable we were able to pull out through the feed-thru hole and wiggle things before reattaching it to the chamber.  Still no change in spectrum.  Boo.

We'll embark on pulling the door tomorrow.

(Sad face.)

Vented Vertex volume

Kyle, Gerardo 

Vent/Purge-air dew point measured -33C at start of vent.  It is expected to be a short duration vent 1 or 2 days with, at most, one BSC door removed.  

No ALS retro-reflaction from EY yet

Green beam was injected into TMSY and into EY, green centering on TMS QPD is working but no retro reflection from EY. I scanned TMSY PIT and YAW and observed green beam in ISCTEY but it would be much easier to just look at the beam in chamber. Will continue tomorrow.

EY was put back into laser safe.

CDS maintenance summary

PSL OPC update for 70W amp install:

Peter, Dave:

The OPC Beckhoff controls system in the diode room had a software update as part of the 70W amp install. This resulted in 25 additional channels. I re-generated H1EDCU_PSLOPC0.ini. I still need to regenerate the SDF monitor.req and restart/reconfigure the SDF.

h1iscey accidentally glitched:

CER activity glitched all models on h1iscey at 15:01 PST. I restarted these models at 15:23 after said activities completed.

Latest Slow Controls Code, Corner Station PCL3 and PLC4:

Daniel, Dave:

I installed Daniel's latest changes to h1ecatc1plc[3,4]. I used my new spiffy update_beckhoff_daq_target_sdf_configuration.py script to automate creating the INI, autoBurt.req and SDF monitor.req files. I restarted the associated SDF targets (h1sysecatc1plc[3,4]sdf), and accepted and monitored all the new channels.

Slow Controls EY PLC2 ring buffer error:

While verifying the h1ecatc1plc[3,4] changes, I found a channel access error to h1ecaty1plc2. Daniel found that this system failed Friday 16th Feb with a "cbHigh ring buffer full" error. No new channel access connections were being honored. Daniel restarted this IOC.

Cell phone alarms system reconfigured.

WP7208. Chandra, Dave:

I returned the alarm level of PT124B_TORR from 7.0e-09 to the nominal value of 5.0e-09 and closed this work permit.

DAQ FW0 E18 firmware upgrade

Greg, Dan, Dave:

Dan upgraded the firmware on the E18 raid array associated with h1fw0. This was a staggered update/reboot of the two controller cards. We tested that this could be done hot, with the frame writer still writing to this file system. This was a partial success, h1fw0 was indeed able to write frames over the upgrade, but LDAS had read errors. We will test this more next Tuesday when fw1's E18 is upgraded.

DMT test machine patched/updated

Greg patched h1dmt3, see his alog for details.

DAQ Restart

The DAQ was restarted to read the new H1EDCU_ECATC1PLC[3,4].ini and H1EDCU_PSLOPC0.ini files. The EDCU is now GREEN.

More files not executable in new 1.8 userapps

Ed found a few more files which did not have the executable bit set in the userapps repository (sys/h1/scripts/hepi-trends.py and psl/common/scripts/PSLweekly.py). I fixed the executable bit, but we are getting "leapsecond data expired errors" on hepi-trends.py, investigating this.

SHG refl/trans power

For a direct comparison to Maggie's alog37867 I attached a 2-day plot of SHG transmitted and reflected power (+ all other relevant channels) stopping right before a temporary TEC cable was removed:

CH1 = SHG crystal temperature, kept at 35.9 deg C where the green conversion was optimized.

CH2 = Red transmitted power through the SHG (16Hz channel)

CH3 = Mephisto laser power (locked to PSL for the most part)

CH4 = Temporary temperature channel (sensor installed after Feb 8th 00:00:00 UTC). A resistor was taped on to the table right next to the SHG housing (Calibration: 1638.4 counts per Celsius).

CH5 = Green reflected power (16Hz channel)

CH6 = TTFSS locking status.

So far we don't see the fluctuation that LLO is seeing. It's not the most stable looking power trend because we couldn't live without opening and disturbing the table for long (+ PSL was not in its best behavior that week). Once the SHG is locked and undisturbed for long enough time we can start characterizing it more seriously.

Flippers & fiber switch

The TwinCAT code and corresponding medm sreens have been completed for the motorized flippers and the remote fiber switch. There is now a flipper overview screen available. Final testing is needed for the fiber switch when it arrives.

The Electric Field Inside BSC10 (ETMY's) Chamber

S. Dwyer, J. Kissel, B. Weaver, R. Weiss

Sheila, Betsy, Rai, and myself measured the electric field inside BSC10 (ETMY's) chamber yesterday using an electric field meter developed by Rai (see T1700569). The experimental setup is show in the collection of pictures attached below.

We had three goals with the measurement:
(1) Characterize the broadband field.
(2) Confirm that the BSC-ISI's capacitive position sensors (CPS) don't create an excessive field inside the chamber (as was the case at MIT)
(3) Use the data to decide whether we need to vibrationally isolate the future in-chamber field sensor (see D1700365).

I attach several sets of plots comparing different measurement scenarios:
- In the lab, on the EE bench, immediately after calibration
- In chamber, with the sensor sensitive to the longitudinal direction (i.e. +/- Y global), exposed to the entire chamber that is sealed with a foil door.
- In chamber, in the longitudinal direction, shielded with a crude foil Faraday cage about 4 inches larger than the sensor in all directions.
- In chamber, in the transverse direction (i.e. +/- X global), exposed to the full chamber, sealed with foil
- In chamber, in the transverse direction, shielded with a foil smaller faraday cage, but the data is junk because I forget to reset the input range of the SR785.
The above data sets are shown in the set of plots at various levels of zoom in frequency. I also attach the raw ASCII data for your perusal if need be.

EDIT: The previous posting of this aLOG made all statements about and plots of electric field strength in V_{rms}.Hz^{-1/2}, but that was merely taking the raw voltage output of the SR785. The SI units for electric field strength is Volts.meter^{-1}. As Rai comments in LHO aLOG 40597, the calibration of this voltage into field strength is Volts / (Volt/m) = 2.1e-2. I've now calibrated the data both in the posted plots and text files and corrected all statements. Apologies for the confusion.

The data is collected from 1 Hz to 50 kHz, which completes goal (1). However, is not as satisfying as one could hope -- namely the crude shielding did not cleanly isolate / identify which spectral features were of the chamber or that of the sensor. But we think it's enough to accomplish goals (2) and (3).

Yet -- We can confirm that the BSC-ISI's CPS clock frequency at 24.82 kHz has an amplitude of only (at worst) 6e-5 (V.m^{-1})_{rms}.Hz^{-1/2} [with an 8 Hz bin width], which is not the dominant field strength inside the chamber.

At low frequency, given that we see many broad features (e.g. at ~25, ~55, ~80, ~130, ~191 Hz) that they change with location (lab vs. chamber) and direction (longitudinal vs transverse) we assume are acoustic. Rai suggests this is enough evidence to convince him that the future field meter needs to be vibrationally isolated, i.e. mounted onto Stage 2 of the BSC-ISI.

As Rai also suggests in LHO aLOG 40597, we should continue exploring the chamber with a few extra scenarios, namely attempting to turn off successive electronics, and/or try to mount the sensor on some sort of small isolation table.

A final note on the instrument -- it is sensitive to time-dependent magnetic fields (also present in the chamber) as well as static electric fields. Further the instrument and the cable readout are sensitive to acoustic vibration. During the measurement, all persons were quiet and still, but the end station itself is LOUD due to purge air and clean rooms. Further potential exploratory measurements besides turning things off would be to intentionally drive either a magnetic field or acoustic excitation near the instrument to further shake down the noise budget of the attached spectra. All exercises will be balanced against person power, time, and priority in conversation with all involved.

For now, we've left the sensor in BSC10 with it sealed with the foil door. We (Sheila, Betsy, and I) hope to get back to it on Wed/Thu/Fri.

PSL Weekly Report

Laser Status:
SysStat is good
Front End Power is -0.002755W (should be around 30 W)
HPO Output Power is -0.04998W
Front End Watch is RED
HPO Watch is RED

PMC:
It has been locked 0 days, 0 hr 0 minutes (should be days/weeks)
Reflected power = -0.0162Watts
Transmitted power = -0.02476Watts
PowerSum = -0.04096Watts.

FSS:
It has been locked for 0 days 0 hr and 0 min (should be days/weeks)
TPD[V] = 0.06647V (min 0.9V)

ISS:
The diffracted power is around 2.6% (should be 3-5%)
Last saturation event was 3 days 22 hours and 17 minutes ago (should be days/weeks)

Possible Issues:
Front End Power is Low
FSS TPD is low
Frontend flow warning, see SYSSTAT.adl
Epics alarm, see SYSSTAT.adl
Power meter flow error, see SYSSTAT.adl
LRA out of range, see SYSSTAT.adl
Check diode chiller
Check Xtal chiller

 

Shift Summary - Day

14:45 Chris to end stations for engine hoist moves

15:31Mark to EX to move engine hoist

16:00 Kyle at MY

16:30 Betsy into LVEA (biergarten) to have a look

16:31 Kyle back; Chris back and into LVEA

16:42 Cintas on site

16:42 Kyle to EY to recover moisture meter(s)

16:59 Sheila going into the optics lab

17:00 Chandra at EY with MCE

17:03 Chris and Mark to MY

17:07 Betsy out

17:08 Jeff B into cleaning area and possibly into LVEA

17:16 Kyle and Gerardo out to LVEA to begin CS venting process (WP 7538)

17:52 Norco on site with LN2 delivery to MY dewer

17:55 Hugh out to HAM6‌ for cleanup and looking for Viton

17:59 2nd Norco delivery on site heading to the other MY dewer

18:03 Fil heading into LVEA for cabling

Kyle and Gerardo out

18:09 Portable toilet service on site

18:10 Jenne, Tvo ad Evan to LVEA - taking posed photos

18:11 Jeff B out

18:11 Multiple WD tripped: BS, ITMX, ITMY(St1&2 all), HAMs 2,3,4,5

18:20 Corey out to Optics lab and then out to LVEA (ISCT1)

18:21 Jenne, Tvo and Evan back

18:55 reset all aforementioned WD trips

19:01 Jeff B to out-buildings to check dust monitors

19:05 all aforementioned WDs . re-tripped. (probably due to work being done with electronics)Jim reported that damping loops are still on.

19:48 Corey out

20:44 MCE out

21:01 Sheila and Terry out for lunch

13:23 Hugh out to HAM6 to torque bolts

21:29 Peter headed to the PSL enclosure to retrieve equipment

21:41 Gerardo to LVEA to retrieve humidty meters to bring to EX for tomorrow's vent

21:42 Betsy out to LVEAto start prep for the in-vac cable repair at BSC1

22:12 Hugh back from HAM6

22:13 Betsy back from BSC1

22:20 Jeff B

22:30 Hugh out to LVEA

22:42 Sheila back out to Optics lab

22:43 Betsy out to LVEA

22:45 Travis out to EY

22:48 TJ out of LVEA

22:54 Hugh out

23:04 TJ ad Alvaro out to optics lab

23:19 Gerardo back

23:21 Betsy and Gerardo out to LVEA/BSC1