The weekly 40m group meeting

Usually held somewhere outside on the Caltech campus

Meeting Notes

40m progress tracking Link to this document:

https://docs.google.com/document/d/1s48wkGhc-hVwdn45RPrRxk1SRY8rYahK7YNzJqg4GxY/

40m weekly meeting every Wednesday 1PM-2PM Link to weekly zoom meeting:

https://caltech.zoom.us/j/234764800

40m BHD Git:

https://git.ligo.org/40m/bhd

Meeting 5/22/2024

- All of our UPS systems should be APC Company. This should be a swap made for the Nodus UPS. WE CANNOT HAVE NODUS GOING DOWN SO OFTEN.

- Rana will contact Derek about updating the Summary Pages. He will also take care of getting rid of the Megatron Computer.

- Adjust the REFL Phase until the REFL_Q phase becomes tiny. Lock the 3f PRMI, DO NOT HAVE THE UGF OF THE LOOPS JACKED UP.

- How can we measure the RAM? Measure at the place that bothers us, the REFL 3f detector (With ITMs and ETMs misaligned to get the straight PRM Shot). Go beyond the 2nd order bessel function. We care about the DC part, after the dark offset, get the bright offset. If the Q signal is half, we have to reduce the RAM. Buy bubble levels and place around the tables. Small ones.

- Add Temperature Changes to my monthly checklist. Anomolies to get graphed through my NumPy skills.

- We want to check if the LIGO Data server has the same data that we have in the Jetstor. We may have to purchase a card to access the legacy interface. We can remove jetstor and store it somewhere in the meantime if we need to.

Meeting 5/15/2024

- The Y arm transmission is dependent on the input alignment, but the X arm is immune to that for some reason. Is there clipping behind the BeamSplitter? If this comes from the damping actuation, if we tune the coil balancing to have the actuation node then the coupling of the optics should be lower.

- The temperature change in the X Arm triggers the pirani and cathode gauge. p1a triggers a break in the threshold of the interlocks.

- Try using a heat gun or hair dryer to heat p1a and watch the trend to see if they correlate.

Meeting 5/08/2024

- 3f PRMI locking was not stable when offset from the resonance. We should do the test of locking and drive the arms around while looking at DARM Signal. Making the MICH Bandwidth is really bad. Get the arm disruption data.

- Why do we have so many ND filters in front of REFL165. Gautum used to use REFL165 to lock MICH.

- CARM offset affect the 3f offset based on previous elogs from Gautum.

- We will try locking using REFL165. This will allow us to understand what is going on a bit more.

- For modulation depth testing we can do an arm scan using the ALS. Scan one FSR and find the sidebands. Shouldn't be below 0.05 and not above 0.5, somewhere in between.

- Get the AC belt to be fixed from 8:00AM-10:00AM on Fridays.

- BHD Finesse model. Aaron should use the sanctioned filter files.

Meeting 5/01/2024

- The OPLEV Loops are all AC. Once PRFPMI is locked, do we switch these to DC just in case there is alignment drift. This may help, but we don't understand it completely. Gautum did this when he locked PRFPMI.

- The previous year, we spent $1761.24 on N2 Cylinders for the Vacuum system. How much will it cost to make a permanent fix, and how long will it take for this upgrade to pay itself off?

- The sidebands change on MICH. What are the Sidebands change relative to the Carrier ? The is always a "Sign Flip" somewhere that needs to be flipped. We can't do a Mich lock until the PRCL lock happens. Once this is squashed, we can actually see a REFL Q signal (Looks VERY SIMILAR to Mich Signal!) Have all the whitening on, even if we staurate PRCL, it's OK. Make sure the Demod phase setting is precise. Tune the REFL Demod phase and watch the NDSCOPE until the Main PDH signal is very tiny.

- Why do we use REFL11? The Michaelson transmission is Sine and Reflection is Cosine. Q signal would go up because we get more action with the phase shifting.

- Look at the Time-Series of the PRMI Dithering lock and compare to the last Lock.

- Could we get a calibrated PRMI Carrier Spectrum.

- Physics toolbox or phyphox to see where this 37 Hz.

- Plot the Sum for all of the Optical levers and post to the elog once a month. Use NumPy and MatPlotLib sum value of 1 on the left hand side and show how it degrades over time.

-

Meeting 4/18/2023

- We need to do PRMI Carrier Noise Budget AND PRMI Carrier Noise Budget BHD.

- The new noise budget must individually plot the DAC, Dewhitening, ADC, Whitening, and coil drivers.

• - This is distinct for the new noise budget.

  - Measure —> Multiply by(1/f^2) —> Boom!

- Make an email notification so that we get pinged when the summary pages go down.

- (ALEX) Pick line frequencies & LPFs correctly and demodulate the data.

Meeting 4/5/2023

·Our look back time on the hard disks should increase , how do we do this ?

·In PRMI Testing, longitudanal damping gives us pitch feedback.

·AS Port has power repetition W/ PR Gain find the Contact Defect

· Create a PRMI noise budget and model, (First a model):

• ·Here's what we got: ·Here's what we need: ·Here's the next step to make this work:

Meeting 3/29/2023

- [ ] DOF TO COIL MATRIX

- [ ] NOT ALL THE SUSPENSION SCREENS SHOW THE ACTUAL CURRENT BEAM and ADD the UTC

- [ ] Burtrestore should not be adjusted the dark noise files.

- [ ] Chris will come setup neuronetwork controllers.

- [ ] Parallel sensing matrix to give us estimated beam spot positions based off of our wfs in close to real-time. (Assuming input beam does not move below 10 Hz)

- [ ] In the carrier lock turn of whitening, dewhitening, and all other stuff.

- [ ] We’ll will need to change PR2 once OMC is inserted. OMC cannot handle what the passive power is with PR2 @ 2%. We want 0.1%.

March 22,

- [ ] Purchase a new computer to replace Allegra. This will be similar to the Rossa computer, but with the technology update.

- [ ] After the BHD LO Scheme, we will start to look forward to PRFPMI. We need to Lock PRMI, X arm Green, and then fix the CARM Offset.

- [ ] We need to create a noise budget for the Carrier PRMI

- [ ] BH55 works better than BH44 @ LO Phase for some reason. . . . Witness sensor for the LO Phase measurement?

Feb 15, 2023 (Wed)

- [ ] Anchal needs to teach others how to lock the arm cavity WFS.

- [ ] 60 Hz NOISE:

• · For MC1 and MC3

  • ·MC1 and MC3 have a 28 Hz LPF. Elliptical Filter. ·Either the hardware OR software filter should be on. NEVER BOTH.

  ·For MC2

  • · The 28 Hz damping filter should always be on.

    · 28Hz LPF should for on the damping loops and affect ASC PITCH & YAW. Affects every except the LSC Path. · The DAC is noisy. There is a gain of 1 @ low frequencies and a gain of 10^-2 @ high. · Used for the Common mode Servo.

  · FOR ALL

  • ·MC WFS, All 3 need to be driven by the same Transfer Function ·All MCs have the have the same damping function.

- [ ] X Arm - green Beam.

• · Plot the noise, error, and control signals. Use the MOKU:PRO to get all 3 in the same time series. · Tune up the servo. We could be getting noise from the environment, or the module itself. · MC Lock beat note of the infrared and red. · Use an iPhone the check the frequency domain. Use an accelerometer app, this is good enough.

Feb. 8, 2023 (Wed)

- [ ] Jc and Koji have met with Steve to talk about removing the large optical table from the lab area. MC2 is very delicate, so be cautious and midful of the about of clearence we have when passing the table thorugh there. This will be put into SolidWorks and tested how we can moeve the table through the lab.

- [ ] Slidervalues for all suspensions should be changed to microRadians. (Optical Lever Tables) Give these counts an actual unit. Roughly 30% is good enough.

- [ ] MC takes away jitter from the Input Beam. This gives us less noise.

- [ ] Add the Null stream to the Summary pages. (This is for Alex)

- [ ] Take the MC lock, IR beat and see if they have a 60 Hz noise. We need 3 beats for 3 lasers!!

- [ ] Read Groudning and Shielding by Ralph Morrison

Oct. 26, 2022 (Wed)

- [ ] Separating the Tourist Laser Safety goggles from the Worker goggles. Adding a rack for the goggles in the control room for easy access.

- [ ] IFO Planning : Where are we now and where are we heading ? BHD was locked with MICH Offset and Dithering on. Only LO Phase is locked. If we can BHD with dithering, we should be able to reduce the offset to 0 without significant change. Noise budgeting for BHD with dither on. Maybe change the coupler and get more light on the RFPD.

- [ ] For the CDS Upgrade, We have to move Megatron to 1X7. Is it possible to add Optimus into Megatron. We need to analyze everything that Megatron is doing. FB1 is the most important. Put them all into the test stand.

- [ ] JC has been working on removing old cables from the rack. Would cutting the cables be ideal since we have a good stock ?

Oct. 12, 2022 (Wed) **Short Meeting**

- [ ] Create a shutdown script for the new CDS Setup

- [ ] Check the cable for the GPS Timing. SAT are not always being read and occasionally free running.

- [ ] Create a circuit board on EAGLE for the Acromags. This will allow us to use the new coil drivers.

Sep. 28, 2022 (Wed)

- [ ] TT1 seems to move randomly. Maybe we can install a TT that has monitored motion during the next vent. There is some trouble with the TT because it is designed with an aLIGO Shielding condition. We have clipped this off here at 40m. If we want to use the new TT, we will need to use the new electronics. Double check to see if the TTs have OSEMs. Maybe we decided to only use the coil actuators ?

- [ ] 2 of the whitening filter channels (Board 1/2) are bad. They inject spikes into the signal every half second or so.

- [ ] Radhika has been learning more about 40m from working with Anchal and Paco.

- [ ] Fire Marshall and Peter King will come on October 13th for inspections. - [ ] TT1 seems to move randomly. Maybe we can install a TT that has monitored motion during the next vent. There is some trouble with the TT because it is designed with an aLIGO Shielding condition. We have clipped this off here at 40m. If we want to use the new TT, we will need to use the new electronics. Double check to see if the TTs have OSEMs. Maybe we decided to only use the coil actuators ?

- [ ] 2 of the whitening filter channels (Board 1/2) are bad. They inject spikes into the signal every half second or so.

- [ ] Radhika has been learning more about 40m from working with Anchal and Paco.

- [ ] Fire Marshall and Peter King will come on October 13th for inspections.

Sep. 21, 2022 (Wed)

- [ ] Mich dark fringe, don’t do half fringe or side fringe. This is the prioritized option. DCPD feeds back to Mich. LO and AS must have a phase difference. Mich changes in a freq dependency way and is Asymmetric. Begin asking more questions about phases. How does the AS port work ? The carrier beat against the higher and lower side bands. After looking at DCPD. If we had RFPDs, Mich at Dark fringe, LO field is like a copy of REFL field?… LO has strong carrier AS has almost no carrier, if we can mix the two, we will get a big AS55Q signal. Set a the dMod phase appropriately. If this is wrong, we may lock to the carrier phase accidentally.

- [ ] Back up scheme to lock the LO phase, double digital demodulation may be an option.

- [ ] Yehonathan has ideas. Disadvantage, the signals are very low. Advantage, use audio dither to optimize real locking scheme #DoubleDithering

- [ ] Only spend a week maximum on each task. Don’t spend too much time on.

Sep. 7, 2022 (Wed)

- [ ] Tests on the Suspensions are currently being done and the interferometer is not locked. This morning there was an issue with the HVAC and alignment is slowly being restored.

- [ ] While the suspensions are being tested, we are not using actual units of measurements. We are only using 'counts'. This could cause an issue because we will not know how big of a step is TOO big. We want to avoid damaging the suspensions. We want to revert back to the original threshold of 100 microns.

- [ ] There is a great amount of the cross coupling between the PITCH and POS of the suspensions. Lets look back at the old logs and figure out how this was dealt with before.

- [ ] FPMI noise budget hasn't had any progress yet because we have yet to lock it. We have measured the noise on the arms and look into moving forward with this by the end of the week. We want to find the DAC noise in the noise budget of the system.

Aug. 30, 2022 (Wed)

- [ ] Yehonathan has fixed the PR3 suspension damping by boosting the gains

- [ ] Yehonathan will redo all the loops and the loop algebra

- [ ] Look into the surf 101 Wiki on the 40m wiki.

- [ ] Our focus is locking and bhd. Tega will respond in correction to the graph posted onto the elog so that Rana could understand the axis’. Go back into the old Elog entry and correctly do impulses on the optics.

- [ ] Step in the position of the actuator record all dof. Repeat this for each actuator. A written procedure will have to be made for this between Rana and Anchal.

- [ ] Tega has ran into the issue of Chiara(clone) somehow having updated information and being in sync with the main system. We must make sure that there is a break between the test stand and the main system.

- [ ] Try to get everyone to git commit daily. This will be updated and make fit much more useful.

- [ ] FPMI is the next goal after the Surf project is done. Use ifo configure scripts. This should be the steady state of the lab.

- [ ] Jc will monitor the health of the lab and ensure the summary pages are always working. Also lock the arms in the morning.

Aug. 23, 2022 (Wed)

- [ ] Look into nail polish elogs to have an idea of how to mark tools

- [ ] CDS upgrade - can’t do testing on Cards and startup on drivers. We can’t get interface cards because they are for next Generation. Call the company to see if they have something that is compatible to Gen 1. Get spares even if our FrontEnds from LLO have them.

- [ ] IFO - Recovering alignment, Single arm Cavity. Go to DDT to get the correct timing. Try replacing a SAT AMP box, but create a plan first. (Old ADC SAT AMP data vs. New SAT Amp. ELOG THIS!) Alignment of the arm is important to create a noise budget with live time transfer functions. Still no BHD locking after alignment improving.

- [ ] Put a step into each dof and look at the cross coupling for 30 seconds. Set a DTT template in windows mix. Make sure all dof damp with 5 cycles.

- [ ] Read the Elog about the step by step process instead of posting transfer functions.

Aug. 17, 2022 (Wed)

- [ ] Suspension damping test.

- [ ] Suspension and noise budget.

- [ ] For locking, Ask Jamie to implement Guardian. A software that has states defined for the IFO and has known path from state to state. Jamie can set the framework, then we can update and move forward.

- [ ] The front ends, old and new, have similar specs. Get the test stands working independently for the 4 test stands. The Frame builder is the main priority. The front ends should be interchangeable.

Aug. 10, 2022 (Wed)

- [ ] OSEM Damping is good, but queue is a bit high. Tega is getting information on this and kicking optics. Needs to adjust gain until we get into the ballpark area of what we a re looking for.

- [ ] Looking for increasing Digital UGF. In our DARM loop, it runs at 16 kHz. Take the sampling rate and divide by 100.

- [ ] Direct BHD - We removed large clipping and improved fringing. We need a noise budget the can be consistently updated. ()

- [ ] Mode matching for BHD is at 60%. What is causing this? BHD Fringes are at about 100 per Second. We need to decrease this by maybe LO or AS damping.

- [ ] We need to change Q to 3 or 5 on all WFS (NO HIUGH Q)

- [ ] MICH is around 10 fringes per second. We need to decrease this somehow.

- [ ] Buy adapters, KVM switch. Always accept front end machines, or any extras.

- [ ] Network switch 8 or 16 port.

- [ ] Purchase adapter One Stop Cards.

July 13, 2022 (Wed)

- [ ] Koji will be leaving to LLO within the next couples months for and OMC replacement.

- [ ] Acromags are in a limbo state. We do not know if they have died, or another issue.

- [ ] Work on locking Single Arm AS55 and FPMI

July 6, 2022 (Wed)

- [ ] Choose the toolbox and send the prices

- [ ] GET THE NOISE BUDGETS DONE from .1Hz to 8kHz

- [ ] Tega, make watchdog wiring so in the fast controls, the bias is left the way it is. Outputs matrix has 2 parts. Coil balancing.

- [ ] FPMI Locking- Stuck with POX and POY. Don’t use triggers from now on.

- [ ] Yuta must begin working on the Voyager project.

- [ ] We will have a power shutdown on Saturday and need to prepare for this on Friday

- [ ] How is the Michaelson noise budget ? General noise budgets do not work.

- [ ] Make a spreadsheet for the boxes which are coming in for the CDS Upgrade

Jun 29, 2022 (Wed)

- [ ] Start taking meeting notes -(JC)

- [ ] Arm Cavity Diagnostics and BHD Situation ——————————————— Measured DMod Bod Conversion function, BUT THE NOISE BUDGET SHOULD BE MADE WITH IMPERFECT MEASUREMENTS TO BEGIN WITH. Noise budget should be made for Michaelson, ALS, etc and updated continuously. No SOFTWARE BS. (URGENT)

- [ ] FPMI locking Scheme- has to lock 3 DoF- Com loop, Mich loop, and Dom loop - we want to use REFL 55 for Mich . (Because magnitude of the signal and we get the phase rotation and loop suppression Q curvature signal I’m balance in the side bands Use the maximum side band modulation 55/11) —Anchal

- [ ] Make sure AS55 and REFL 55 checks out. AM Laser checkout(Put frequency off set a few times.Make sure beam is small (half mm diam) don’t hit the bonk wire. ( This is on the back burner)

- [ ] Increase mHz modulation Depth. And look at the RF Distribution.

- [ ] Team Arm Cavity —Paco and the SURFs—check if the arms are fine

- [ ] Find out the situation with AS WFS. We just want the arm cavity modes to overlap.

- [ ] Yuta needs some faith - Don’t Stop Believing - Journey.

- [ ] Tega will work on CDS upgrade.

- [ ] Try locking FPMI in day time.

- [ ] “Elephant request will never come (from future graduate students)” - Anchal

- [ ] After 6pm, the shakers in the Milikan Library may act up. (Search on StripTool)

Jun 17, 2020 (Wed)

Agenda Vacuum Failure: Make a list of maintenance purchase (Jon). Status of SolidWorks layout -> Interferometer Assembly is ready to be populated with optics etc., table holes have been added and are correct orientation Laser Plan: Keep the “2 W” NPRO; what is the duty cycle / pain on this option? Use existing modulators Use the Neolase amplifier (but where is it?) BHD Optics Stock Optics Option fixed 40m BHD Procurement Layout with the stock optics/custom optics: transition with moving AS3, LO3, and ASL (lens) Preliminary thermal mode matching result: ~10mW absorption seems to improve the MM. BHD Mechanics: Breadboard -> Provide the precise positions of the OMCs/Optics/Mounts Suspensions: 2”-3” sleeve design [Caltech Box Link for the SLDASM file] -> Design metal clamp Remote access to the CAD WS / etc Jordan - CAD WS 10:30am - 2pm How about use the Mattermost to “login” and “logout” of workstation? -> (KA) Mattermost is also OK to reserve/login/logout. I’ll setup the protocol for the WS use.

Jun 16, 2020 (Tue)

Progress Jordan, Jon, Koji: The pumping down of the main vacuum volume has been resumed. The TP3 backing pump was not at its full performance for a year and particularly since this Jan. TP3 had been running close to it’s max current and the rot speed was reduced ~50%. To solve this issue, the spare dry pump was connected to TP3. This resumed the foreline pressure of TP3 sufficiently low. Full details by Jon [ELOG 15402] Jordan, Koji: Jordan transported the spare ETMs (ETMU06/ETMU08) to Downs and picked up the spare ITMs (ITMU01/ITMU02) and E1800089 optics. [ELOG 15401] Jon finalized the stock/custom optics specs. Koji finalized the optical layout based on Jon’s optics selection. The RF AS beam now has a f=1000mm lens on the BS chamber such that the beam is sufficiently small along the path. Note that we have to shift the position of this lens when we switch from the stock to custom relay optics.

Remote access to the CAD WS / etc Koji CAD WS: 6:20pm-midnight

Jun 12, 2020 (Fri) Progress Jordan, Jon, Koji: Worked on the vacuum recovery [ELOG]. Resetting the TP2 controller did not help. The next plan is found in the elog Solidworks model for the 2”->3” metal sleeve [Caltech Box Link for the SLDASM file] Still needs to implement the pitch balance adjuster How can I measure the COM in SolidWorks? How to figure out the adjustment range in SW? The mass is significantly lighter. Do I need to adjust the geometry of the standoffs? The optic is specifically 1/4”. No other option. Didn’t check how the wedged optics is accommodated. Standoffs: Should we replace it with the metal clamp? Or have grooves so that we can glue ruby standoffs without a special fixture? Any other feedback?

Remote access to the CAD WS / etc Jordan - CAD WS 930am -12pm

Jun 11, 2020 (Thu) Progress Jon: Conclusions for BHD relay optics (telescopes) Go with commercial optics for initial implementation (Lambda Research Optics; ~95% MM; ELOG 15379) Proceed with plan to procure custom curvatures for final optics (>98% MM with 90% probability; ELOG 15357, DCC E2000296) Final distances for commercial-optics design in ELOG 15389 Physical presence at the 40m / Remote access / etc Koji CAD WS: 1pm-3pm, 4pm-4:30pm, 8:30pm-

Jun 10, 2020 (Wed) Weekly Meeting CANCELED FOR THIS WEEK

Jun 9, 2020 (Tue) Physical presence at the 40m / Remote access / etc Koji CAD WS: 7pm-

Jun 8, 2020 (Mon)

Physical presence at the 40m / Remote access / etc Jordan- CAD WS 10am-2pm Koji CAD WS: Once Jordan is done.

Jun 7, 2020 (Sun)

Physical presence at the 40m / Remote access / etc Koji: Cad Machine 8pm-midnight

Jun 5, 2020 (Fri) Progress Jon: BHD mode-matching options Option 1: Stock optics [ELOG 15379] Option 2: Optimal custom-curvature optics [DCC E2000296] Last week we discussed starting with stock optics, then upgrading to custom ones at a later time (once very low loss/scatter have become more important) Koji: Sent Jordan the description of what to do with the invac table to make it accurate in SolidWorks. (Large holes on the table / Orientation of the table in the IFO model)

Physical presence at the 40m / Remote access / etc Jordan- Will be in Clean and Bake Lab 9am-3pm

Jun 4, 2020 (Thu) Progress Koji: Analysis of the phasemap measurement for the new PR3 mirrors [Link]

Physical presence at the 40m / Remote access / etc Jordan- Will be in Clean and Bake Lab 9am-3pm

Jun 3, 2020 (Wed) Weekly Meeting Agenda/Minutes Locking PRG ~19 T240 Electronics 40m Summary Pages [Link] BHD CDS Timing master BHD Optics Mode matching We need the decision about the relay optics. - Do we rely on the super-polished optics? - Are we going to start with the off-the-shelf optics? Aux optics Y1-2037-0-3.00CC-AR or equivalent Qty1 (Lens option, check the scatter?) 2” mirror for oplev Qty 4 532nm 0deg (do we have?) OMC REFL mirrors 1” 0~45deg HR Qty 6 (how many G&H do we have?) Aux optics / relay optics posts Power adjuster - Rana will talk to Rick BHD Mechanics 2” mirror ->3” sleeve (KA: Sketch) SolidWorks Table model BHD board model (AutoCAD: parts coordinates list?) Optical Layout BHD Electronics Screaming Circuits / Zachary Washington To be designed (Cardiff) 4ch Cardiff DCPD Amp (Cardiff) DCPD Whitening Field Amp (4ch) Passive cross connect type units End ADC Adapter End DAC Adapter Custom DB25 Cable for Dual Sat Amp (cable) Legacy Coil Driver Adapter Sat Amp Adapter Coil Driver Adapter BHD Adapter Unit (HV Coil Driver with Dewhitening)

Loss calculation Mode Scan - using aux green (Yehonathan / Tega) Phasemap Garilynn has finished the measurement of the 5 new PR3 optics (1064nm, 45deg HR) Also the initial scan of the ITMs are done. It needs some refinement (due to the dust on the optics etc), but the initial data set for constructing the analysis codes were obtained.

Physical presence at the 40m / Remote access / etc Jordan- CAD WS 10:00am- 1pm Gautam - CAD WS 11pm-2am

June 02, 2020 (Tue) Progress Hang: Alignment range requirement [ELOG 15363] Koji: Updated timeline [Caltech BOX link]

Action Items Optics We need the decision about the relay optics. - Do we rely on the super-polished optics? - Are we going to start with the off-the-shelf optics? BHD and other off-the-shelf optics Mechanics design 2”->3” sleeve design

BHD board design BHD board in-vacuum opto-mechanics downselect Custom electronics design

Physical presence at the 40m / Remote access / etc Jordan-Will be in the Clean and Bake lab 9am-4pm

Jun 01, 2020 (Mon) Physical presence at the 40m / Remote access / etc gautam - CAD WS 10:20am- 11am

May 29, 2020 (Fri) Physical presence at the 40m / Remote access / etc Jordan- CAD WS 10:30am- 3pm

May 28, 2020 (Thu) Physical presence at the 40m / Remote access / etc Jordan-Will be in the Clean and Bake lab 11am-4pm

May 27, 2020 (Wed) Weekly Meeting Agenda/Minutes Solid Works Model BHD Mode matching - Final solution https://nodus.ligo.caltech.edu:8081/40m/15357 Optics Vacuum Flange - To order Power adjuster - Rana’ll talk to Rick 40m IFO Mode Scan - using aux green (Yehonathan / Tega) ITMU1/2 & 5x new PR3 Optics -> Garilynn for the phasemap measurement Locking summary? Loss calculation Summary Pages Physical presence at the 40m / Remote access / etc Koji: CAD WS 9pm-10:30pm

May 26, 2020 (Tue) Progress Jon: Compiled list of outstanding BHD design issues in git readme There are five. First two must be addressed before relay optics can be ordered: OMC mode-matching loss due to astigmatism (non-normal AOIs) OMC mode-matching loss due to thermal lensing in the test masses Discussion today with Hang and Tega: Hang is already working on incorporating AOI dependence into his mode-matching analysis Tega has been getting up to speed in Finesse and volunteered to take on the thermal lensing analysis (Jon will assist as needed) Our plan is to start by deriving requirements on the common and differential ITM lensing: In the 2D space of common vs. differential lens power, we can calculate OMC iso-mode-matching contours This will identify the requirements on common and differential lensing for, e.g., < 2% output mode-matching loss From the lensing requirements we can then extract requirements on physical parameters (e.g., HR surface absorption)

Physical presence at the 40m / Remote access / etc Jordan-Will be in the Clean and Bake lab 8am-11am

May 22, 2020 (Fri) Physical presence at the 40m / Remote access / etc Jordan-Will be in the Clean and Bake lab 8am-11am

May 20, 2020 (Wed) Weekly Meeting Agenda/Minutes BHD Mode Matching - Produce corner plot Aux Optics/Optical mount - now counting Output Faraday Isolator - What’s the aperture size and where should it be placed? NDS2: John Zweizig is looking at the NDS2 setup. Loss Yeonathan/Hiro calculated HOM scattering loss ~ consistent

Physical presence at the 40m / Remote access / etc Koji: Plans to stop by 40m 3PM-4PM Koji: CAD WS 3pm-5pm

May 19, 2020 (Tue) Progress Jon/Hang/Tega: BHD telescope design options Comparative Monte Carlo analysis from Hang LO path: Two good options. Option 1 - Most stable design Advantage: Very robust to distance/RoC errors (<1% MM loss with 100% probability) Disadvantage: Requires actuating on LO4 (breadboard redesign to accommodate LO4 SOS footprint) Option 2 - Increase LO1 curvature Advantage: Allows actuating on LO2 as originally planned Disadvantage: Larger but still acceptable sensitivity to distance/RoC errors (<2% MM loss with 90% probability) AS path: No good options. No choice but to actuate on AS1 and AS4. Sensitivity to distance/RoC errors is unacceptably high (~40% probability of a MM loss larger than 2%). We need to consider redesigning the relay path. (One way to make AS more symmetric to LO path would be to add length).

Physical presence at the 40m / Remote access / etc Jordan: CAD WS 10am-3pm

May 18, 2020 (Mon) Physical presence at the 40m / Remote access / etc Jordan: CAD WS 8:30am-10am

May 15, 2020 (Fri) Progress Koji: Made the optical layout of 2020/05/15 version. AS4 and LO4 are suspended instead of AS2/LO2 [Link to the combined PDF in 40m box] The pathlength list was updated on a separate sheet named "2020/05/15":

• [Spreadsheet Link]

The changes are marked with the red text.

Physical presence at the 40m / Remote access / etc Koji: Remote CAD WS 8:00pm-10:00pm

May 14, 2020 (Thu) Progress Koji: believes that the optical layout is complete for now. A single packed PDF [Box Link] The Optics list has been updated. Still needs some clean-up. [Link to the purchase list spreadsheet]

BHD BS orientation fixed. POY beam was steered to the BS table. I decided to do this as I did not want to deal with the accuracy of the ITMY wedge angle. As per Gautam’s suggestion, the green transmission from both arms were guided to the BS table. The optical distances have been updated accordingly. [Spreadsheet Link]

Physical presence at the 40m / Remote access / etc Koji: Remote CAD WS 1:30pm-4:30pm, and 6pm-11pm

May 13, 2020 (Wed) Weekly Meeting Agenda/Minutes 40m IFO Locking [ELOG] What may interfere with the locking work? IMC Injection megatron NDS2 configuration Sometime in May, seismometer check (SURF) BHD [Link to the purchase list spreadsheet] Ongoing: Telescope design / ASC gouy phase CDS procurement Flange quotes Mechanics / Optics Progress Jon & Hang: SRC cavity design GV’s proposed redesign (evaluated against the final distances) checks out 👍 ✓ No co-resonances below order 8 (0.3 deg change in Gouy phase) ✓ Matching to common arm mode: 0.998 (power) No new optics required (SR2 optic moved to SR3 location, SR3 optic removed) Slightly higher cavity loss: Folding mirror transmission will increase 20 ppm → 75 ppm because SR2 is coated for 0 deg AOI. Partially offset by eliminating the transmission loss from a second folding mirror. Net loss increases ~35 ppm Jon proceeding with final telescope design using the SRC mode of this design Physical presence at the 40m / Remote access / etc Koji: Remote CAD WS 4:30pm-4pm and 7:30pm onward

May 10, 2020 (Sun) Physical presence at the 40m / Remote access / etc gautam: N2 replacement ~4pm, locking activity till 7pm

May 8, 2020 (Fri) Physical presence at the 40m / Remote access / etc Jordan: Remote CAD WS 8:30am-12pm

May 6, 2020 (Wed) Weekly Meeting Agenda/Minutes 40m IFO IMC WFS [ELOG] ALS excess noise: Optomechanical effect during CARM offset reduction [ELOG] BHD KA: BHD Optical Layout Latest draft [Box Link] - most of the optics are already fixed. Optical path lengths between the optics [Spreadsheet Link] KA: Current flange layout [Box Link] Added the new flanges to the purchase list [Link to the purchase list spreadsheet] https://www.accuglassproducts.com/custom-10-cf-flange

This looks OK (just have some extra). We still need the 8xDB25 flange.

Or, just buy 6 of this (dropping the octa-DB25). Chub: Timing chassis RXA ask Daniel Sigg to find the simpler solution Optics Do we really want to replace PR2 at the current stage? -> Stay with the current PR2. Any apparent drawback which holds up the experiment? List up non suspended optics so that we can order them next week. Let’s consider the in-air BHD. Use the unmodulated pick of as the LO vs the AS beam To do or not to do the mini vent?

Physical presence at the 40m / Remote access / etc

May 5, 2020 (Tue) Progress 40m current flange layout: We have plenty of blank flanges. A few spare DB25 available. 40mBox: /40m/BHD40m/Electronics/wiring/40m_flange_layout_20200423.pdf

Physical presence at the 40m / Remote access / etc Jordan: Remote CAD WS 8:30am-12pm Koji 3pm-4pm: stopped by the lab to check the flange configuration at the vac chamber.

May 4, 2020 (Mon) Progress Koji: Optical pathlengths between the optics for 40m BHD [Spreadsheet Link]

Physical presence at the 40m / Remote access / etc Jordan: Remote CAD WS 10am-2pm Gautam: RemoteCAD WS 1130am-1145am (I just need to zip some Altium files to send to Rich). Now done. Koji: Remote CAD WS 230pm-

May 3, 2020 (Sun) Physical presence at the 40m / Remote access / etc Gautam: I will use the CAD WS from 1pm-4pm on May 3 2020 (Sun). And again 10pm-1am.

May 2, 2020 (Sat) Physical presence at the 40m / Remote access / etc Gautam: I will use the CAD WS from 11am-4pm on May 2 2020 (Sat). And again 10pm-midnight.

May 1, 2020 (Fri) Physical presence at the 40m / Remote access / etc Koji: wants to use CAD machine 5pm-11pm. Gautam: went to lab to change N2 ~4pm. Also did a checkout of the EY green PZT. also checked alignment of the IFO. I’d like to use the remote desktop for some low-priority Altium work so when Jordan/Koji are not using it, I may use it. I think the optical layout work is more pressing so if either of you want to use the machine, and I happen to be using it, please let me know and I’ll leave. I won’t login if someone else has indicated their usage here.

April 30, 2020 (Thu) Physical presence at the 40m / Remote access / etc Jordan: CAD machine 9am-2:15pm Koji: CAD machine 3pm~11pm.

April 29, 2020 (Wed) Weekly Meeting Agenda/Minutes KA: BHD Optical Layout (draft) Overall [Link] (all files moved to Box.com shared folder 40m/) BS Chamber [Link] ITMY Chamber [Link] ITMX Chamber [Link] OMC Chamber [Link] Highlights The current optical paths between IMC~MMT2 will be inherited. PRC/SRC lenIgths were adjusted ITMY chamber: We now have a zig-zag for the AS beam on the BHD platform The AS Faraday Isolator will be placed right after AS2 suspension. All the lenses should be placed after the FI. OMC2 REFL is guided to the in-air table. POY and AS beams go to the OMC chamber and are detected at the AP table. ITMY oplev beam comes from and returns to the ITMY table SRM oplev beam comes from and returns to the BS table ITMX chamber: POX beam goes to the BS chamber and are directly reflected back to the in-air ITMX table. ITMX oplev beam comes from and returns to the ITMX table BS chamber: Reflect POX beam back to the in-air TMX table. BS/PRM/SRM Oplev beams come from the BS table OMC chamber: POY and AS beams come to this chamber and are steered out to the AP table Open questions: Do we also want OMC1 REFL out? How can we suspend the BHD platform? single pole at the middle blades connected to the pole Beam baffle / beam damps Shapes: specific and generic Material: glass/quartz/polished steel etc Ask Tega for the contribution CDS purchasing [purchase list] Optics list Make the spec more precise now. Suspension List the suspension components (necessary # of components, how many we have, etc) 2”->3” ring design Unify the budget spreadsheet and the purchase list spreadsheet

Physical presence at the 40m / Remote access / etc gautam used Altium on CAD machine 9pm-2am.

April 28, 2020 (Wed) Physical presence at the 40m / Remote access / etc Koji: CAD machine 9pm~

April 27, 2020 (Mon) Physical presence at the 40m / Remote access / etc Koji: CAD machine 9pm~

April 24, 2020 (Fri) Physical presence at the 40m / Remote access / etc Jordan: CAD machine 9am-2pm

April 23, 2020 (Thu) Progress Koji: Working on the BHD optical layout. The main path layout is done. Thinking about the oplev and pick off beam paths. Also working on the BHD sus layout. Meanwhile, I forgot the id/password of SW Vault...

Physical presence at the 40m / Remote access / etc Jordan: CAD machine 1pm-2pm Koji: CAD machine 3pm and onward

April 22, 2020 (Wed) Weekly Meeting Agenda/Minutes BHD: BHD Account: See Apr 21 entry Jon CDS: Purchase list completed - Rana and Chub will order the items. Will obtain the rest from the sites. Jon optics modeling: Mode matching / Can we have more AS path length? Are we going to use curved mirrors or lenses on the BHD platform? Koji optical layout: optics distances / optical lever / ITMY tube picture / Ask Steve https://drive.google.com/file/d/1cQwIxOQo609dkSPkzLZRYgXiTGYPNMgW

Breadboard: https://drive.google.com/file/d/1bTaNtS_JmwxnHnQ6L9WI9COIM1lSe61D https://photos.app.goo.gl/wvUxvNDtN4xEBMFu9

Koji SUS: Asking Syracuse and MIT about the additional SOS parts 2” -> 3” metal sleeve design, Jordan Mechanics: -> will modify the model with the updated optical layout Gautam: 40m recover HV supplies & restarted iscsus/iscaux -> The IFO was aligned Turbo pump getting noisy -> Talk with Chub about the replacement plan Rana: Disk frame backup: Ask Dan for network bandwidth increase Gautam: summary page updated the software / some channels started to work.

Physical presence at the 40m / Remote access / etc Jordan: CAD machine 10am-12pm

April 21, 2020 (Tue) Progress Report Mike Z: 40m BHD account: FABLIGO.ADTR40M/NSFLIGO.1764464 https://dcc.ligo.org/LIGO-M2000059 Please inform everyone of correct PTA to use for materials and supplies Please have all NON-ACADEMIC staff (no students, postdocs or faculty) contributing to this project log their time invested biweekly under "ADTR FABRICATIONS," task “FABLIGO.ADTR40M” Koji: Sent inquiries to Syracuse and MIT about additional SOS components incl. OSEMs

Physical presence at the 40m / Remote access / etc Koji is going to use the CAD machine for the entire afternoon/evening

April 20, 2020 (Mon) Progress Report

Physical presence at the 40m / Remote access / etc Gautam was in the lab ~3-6pm. Empty N2 replaced. Logged back into zita and started the StripTool traces (even though we keep the TV off nowadays). c1susaux acro-crate power cycled to re-enable PRM suspension control (all other vertex optics also now respond to slow bias voltage sliders being moved). c1iscaux needed a hard reboot as it wasn’t seen on martian. I power cycled the crate for good measure. Marconi turned back on with correct frequency/amplitude. c0rga is now seen again on martian network. I re-enabled the RGA scanning so that it takes a scan every morning at 4am. The forepumps for TP2/TP3 are noisier than I remember. The former has ~10,000 hrs on the clock. How often does the tip seal replacement need to happen? HV supplies for ASX/ASY PZTs re-energized. IFO re-aligned for locking. c1oaf and c1daf models restarted. c1oaf required the usual start/stop/start sequence to make the DAQ errors go away, and luckily the FE didn’t crash when the model was unloaded. POX/POY/PRMI 1f carrier/green locking all was smooth. For some reason, the PRC angular FF filters i trained no longer do anything good (but MCL is still good).

April 17, 2020 (Fri) Physical presence at the 40m / Remote access / etc Jordan - Remote into Solidworks WS 11:30am - 3pm

April 16, 2020 (Thu) Progress Report

BHD Optics Specifications (Jon) LO/AS beam calculations uploaded (RoC): https://nodus.ligo.caltech.edu:8081/40m/15305 Optics specifications generated: 2" mirrors (E2000226-v1) 2" 50:50 beamsplitters (E2000227-v1) 2" lenses (E2000228-v1) PR2 replacement (E2000229-v1) List of work before the final specifications can be generated: https://git.ligo.org/40m/bhd/-/blob/master/README.rst

April 15, 2020 (Wed) Weekly Meeting Agenda/Minutes Power Glitch Recovery Recovery Mostly done N2 replaced Remaining Issues IFO alignment The PRM alignment slider has no effect (although the PRM is aligned…) -> SLOW DAC frozen??? -> Jon’s suggestion: Power cycle c1susaux acromag chassis / restart modbusIOC on c1susaux Main marconi forgotten to be turned on JETSTOR is not mounted on megatron

BHD Jon: LO/AS beam calculation to be uploaded today. RoC Make a list of calculation tasks Koji: ask Peter about the # of OSEMs/SOSs Chub: Electronics ordering

Yehonathan: Working on the loss paper Rana: Frame download to Downs. What is MD5 files?

April 14, 2020 (Tue) Progress Report

Koji / Gautam (Remote) All record found on the elog: https://nodus.ligo.caltech.edu:8081/40m/15303 Lab status check Work stations Vacuum status check C1VAC recovery End RTS recovery Vertex RTS recovery Vertex RTS recovery ~ part 2 (Timing, FB) IMC recovery Burt restore / IFO recovery JETSTOR recovery Hardware (NPROs/PMC/SHG) N2 bottle replacement Closing Now the IFO REFL/AS beams were back on the CCDs, Y arm was flashing Remaining Issues [done] MCAutoLocker / FSSSlow scripts are not running The PRM alignment slider has no effect (although the PRM is aligned…) -> SLOW DAQ frozen??? Main marconi forgotten to be turned on JETSTOR is not mounted on megatron

Physical presence at the 40m / Remote access / etc Koji 15:45-20:00 in the lab

April 13, 2020 (Mon) Progress Report

Koji Looks like we have no network access to the 40m lab. Stuart Anderson reported some power event on campus. Still investigating if we need to get to the lab for the recovery. Network recovery (Larry/KA) Asked Larry to get into the lab. 14:30 Larry went to the lab office area. He restarted (power cycled) the edge-switch (on the rack next to the printer). This recovered the ssh-access to nodus. Also Larry turned on the CAD WS. Koji confirmed the remote access to the CAD WS. Nodus recovery (KA) Apr 12, 22:43 nodus was restarted. Apache (dokuwiki, svn, etc) recovered: sudo systemctl restart httpd ELOG recovered: controls@nodus|elog> ./startELOGD.sh Control Machines / RT FE / Acromag server Status Gautam - Judging by uptime, basically only the machines that are on UPS (all control room workstations + chiara) survived the power outage. All RT FEs are down. Apart from c1susaux, the acromag servers are back up (but the modbus processes have NOT been restarted yet). Vacuum machine is not visible on the network (could just be a networking issue and the local subnet to valves/pumps is connected, but no way to tell remotely). Comment by KA: I imagine that FB took some finite time to come up. However, the RT machines required FB to download the OS. That made the RTs down. If so, what we need is to power cycle them. Not sure about this setup for the Acromags. The power was lost at Apr 12 22:39:42, according to the vacuum pressure log. The power loss was for a few min.

April 8, 2020 (Wed) Meeting Agenda/Minutes BHD Dolphin issue Get the cards from LLO Incompatibility between the old cards and the new OS. Use Debian 8 + install new drivers after the OS installation, etc... Electronics ISC whitening boards / IF boards Board stuffing company: Daily On(?) / Screaming Circuits Mechanics Assemble a spreadsheet what we already have / what we want so that we can ask some Downs personnel to help us to order the parts. Laser Aerodiode - It’s like a trial, but we’ll order the laser Optics Use approximate RoC to send out the quotes Noise budget Pygwinc setup: ELOG 40m 15300

SURF Need come up with the computational project, considering the students’ environment 40m: 2 india students / 1 UK - nominal Zoom meeting 3AM at PDT!?!?

Vacuum design / Controls / Equipment KA Replace manual gate valve with actuated one TP/RP capacity Jon Replace the UPS Need a 240V socket for TP1 (currently - the pump most likely to be damaged by a power failure is not on a UPS) Need RS232/485 comms with the interlock server (currently - the interlock server does not know when a power failure has occurred, so cannot shut down pumps and valves before the battery is drained) Replace all the failed pressure gauges (~5) Add more cold cathode sensors to the main volume for sensor redundancy Currently - the main-volume interlocks are predicated on only 1 working sensor (737 MAX...) Replace TP3 The controller is failing (intermittent garbage temp/speed readbacks that were spuriously triggering the interlocks) I think we have a new Agilent available to switch in Remove RP2 It is dead and also not needed We already have to throttle the pumpdown rate with only two roughing pumps Remove or refurbish/replace the cryopump Contamination risk to have it connectable to the main volume (e.g., once during the vac upgrade, we accidentally opened VC1) Fresh new MEDM screens (similar to the sites) Rana Remove N2 cylinders and use a compressor. Current cost: 92 cyrinders/year x $13/cyr ~ $1.2K/year Loss research (Yehonathan/Tega)

April 7, 2020 (Tue) Progress Report

Jon Regarding IPC for new front ends, Dolphin confirmed: The Gen1 cards will NOT work with modern Linux OS There is no way to mix old and new cards Conclusion: we have to either upgrade all the machines (not possible) or install an old OS on c1bhd and c1sus2. Let’s plan to go with Debian 8. Jon Started 40m noise budget migration to pygwinc Details here

Koji Updated the 40mBHD procurement spreadsheet. "Custom Parts Sublist" tab of this link I had some miscounting of the HAM A coil drivers. T -> The number of the HAM A was increased. I reconsidered the Binary Output configuration. -> The number of the BO I/F was increased.

April 3, 2020 (Fri) Progress Report

Jon: Dolphin IPC for new front ends Keith Thorne confirmed we can get Dolphin Gen1 PCIe cards from the sites. They upgraded pre-O3. However he also pointed out a complication: the driver (last updated 2016) is not compatible with the latest Linux kernel. It requires <=3.x, which limits us to something of the Debian 8 era. See details from Keith.

April 2, 2020 (Thu) Progress Report

Jon: c1auxey upgrade Created EPICS database, target directory, and systemd files for c1auxey upgrade Created internal wiring diagram for Acromag chassis See details on elog 15292

Physical presence at the 40m / Remote access / etc Gautam was in the lab 1-4pm.

April 1, 2020 (Wed) Weekly Meeting

Locking: What can we do remotely? IMC feedforward / PRC angular motion feedforward Summary Page / Contact Dan Kozak (Rana) Alex Urban / NDS is ready IFO diagnosis / IFO test Software update: rossa (do not touch pianosa)

Laser upgrade Aerodiode 1064nm DFB https://www.aerodiode.com/product/1064-nm-laser-diode/ 200kHz LW -> ~100x worse than NPRO Combine this laser with the LIGO custom driver ~2000 euro Two downsides: 1) Unknown company 2) Can we really control the freq noise? With RIO as the baseline, all the optics are OK with this low power. With Aerodiode, we buy it for testing. We eventually will have higher power and then will employ the fiber coupled modulators etc. We still need to think about the high power EOM for the f1, f2 modulations (aLIGO RTP EOM?)

Jon CDS: purchase list / Obsolete PCIe Gen1 dolphin IPC card -> Ask Keith Thorne Optics spec: spec spread sheet

Yehonathan BHD angular jitter noise / OMC noise

Yehonathan/Jon EX Acromag c1exaux channel list / wiring

Physical presence at the 40m / Remote access / etc Gautam tried to remotely lock the PRMI but it is proving very difficult without any visual feedback of what the cavities are doing and with the laggy ndscope over ssh.

March 31, 2020 (Tue) Progress Report

Jon Created a unified CDS/SUS electronics purchase order for Rich and Chub. They are going to begin procuring the parts for custom electronics.

Yehonathan Fixed some issues in the angular noise section in the DRD. Added consideration for the angular noise of the OMC breadboard when it is suspended and when it is fixed.

March 30, 2020 (Mon) Progress Report

Koji Worked on the electronics tab of the BHD purchase spreadsheet . Discussion with Yehonathan about the jitter noise at the OMC. Also asked Yehonathan to work on the vibrational effect of the OMC when the BHD platform is fixed on the stack. Physical presence at the 40m / Remote access / etc Gautam worked on some (remote) MCL transfer function measurements from ~10pm-1am.

March 29, 2020 (Sun) Progress Report

Yehonathan Calculation of angular RMS noise. Figure of angular noise modelling in DRD now only shows the projected noise for this RMS noise. Figures now show frequency range from 0.1Hz to 100Hz. Input HOMs spectrum was removed.

Physical presence at the 40m / Remote access / etc Rana went to the 40m in the afternoon to collect the PPE stocks for donation

March 26, 2020 (Thu) Progress Report

Yehonathan I have made a wiring + channel list that needs to be included in the new C!AUXEY Acromag. It was mostly copied from C1AUXEX. I ignored the IPANG channels since it is going to be removed from the table.

Physical presence at the 40m / Remote access / etc Jordan Remote SW WS 10am-12pm

March 25, 2020 (Wed) Progress Report

Jon Set up a spreadsheet for tracking the BHD hardware procurement. (requires ligo.org credentials) So far I've filled out a tab with the CDS components (still in progress). The price column now reflects actual quoted cost, not an estimate. The idea would be to add a new tab for each subsystem into this one central spreadsheet.

Rana Aero diodes - same as RIO CW 200mW -> Neolase, LW - 200kHz RIN - 10^{-7 at 100Hz / 10}-8 above 1kHz Price $3k Advantage: This allow us to lose some power in the modulators before the amplifier

March 24, 2020 (Tue) Progress Report

Yehonathan Input angular noise was recalculated taking vibration isolation stack transfer function into account. Updated BHD DRD angular noise section explaining this estimation and added a figure showing the input angular noise used for the modelling.

Bottomline is that angular detuning of steering mirrors is much more relaxed - Above 35Hz noise requirement is met for all detunings. I also updated the executive summary. Didn’t have anything to write for the angular noise requirement at 100Hz other than “non existent”. Maybe someone else has better phrasing.

March 23, 2020 (Mon) Progress Report

Gautam The source files (LTspice models and data files) used for the satellite box and coil driver noise (sensing and actuation respectively) analysis has now been posted to the dropbox. The conclusions haven’t changed. Worked a bit on reminding myself of the feedforward filter calculation ideas. I decided to work with IMC length feedforward first, with the eventual goal of implementing this for PRC angular feedforward. Some questions: For the pre-filtering by plant mechanical TF - we measure this typically by exciting the optic and looking for the response in the target channel (e.g. MCL). but this is NOT the same as the TF from the seismic to the target channel (stack TF is completely bypassed). Is this a case of partially identifying the TF is better than leaving all params free?

March 21, 2020 (Sat) Progress Report

Koji Working on the BHD electronics diagram -> Done. The diagram and the BOM (except for the ordinary DSUB cables) are found in the 40m dropbox folder. [Dropbox PDF] For the entire BHD project, we newly want: 3 32ch ADC cards 7 8ch 18bit DAC cards 2 32ch Digital Output cards, which can be taken from the existing c1sus We need 132 binary output channels for the ISC whitening and DCPD switching. But I believe all these can be implemented with Acromag. Electronics count [Dropbox Unit_BOM.xlsx]

Physical presence at the 40m / Remote access / etc Koji remotely used CAD WS 3pm~4pm

March 20, 2020 (Fri) Progress Report

Koji Not available this morning -> Back online 1145. Working on the BHD electronics diagram

March 19, 2020 (Thu) Progress Report

Koji Still working on the BHD electronics wiring diagram. Now implementing the intermediate transition state of the coil drivers. I.e. new coil drivers for non-TM masses, but keep using the current dewhitenings and the coil drvs for 4 TMs. Also checking the required # of DO channels.

Physical presence at the 40m / Remote access / etc Jordan remote into Solidworks station ~10am-3pm

March 18, 2020 (Wed) Gautam’s update on electronics noise analysis Coil driver and satellite box preliminary noise analysis - can be found here. In summary, I think that with appropriate modifications, we can use the units suggested for the new SOS optics that will be installed for BHD. The electronics noise of the shadow sensor readout circuit is unlikely to be limiting at any frequency of interest. The replacement of existing coil drivers will need significant modifications. I will upload the source files used somewhere shortly.

We can use this chain for the BHD Relay optics We need custom coil drivers for TMs We need dewhitening for TMs

Koji BHD Electronics Wiring Diagram [PDF] (to be converted to Altium diagram slowly) Total 17 SOS chain completely renewed + 1 SOS equivalent for BHD SUS 2 x OMC electronics chain ~4x 8 DB25 feedthrus # of channels ADC SUS35+BHDSUS6+OMCQPD16+DCPD4+REFLDC1 = 62

• -> 2x32ch ADC cards are just barely enough

DAC SUS35+BHD6+PZT4 = 45

• -> 6x8ch 18bit DAC cards are just barely enough

(18bit DAC has 8 chs. The existing 16bit DAC has 16 chs.) BHD Timeline updated [PDF]

Next pressing item is the optical layout

Procurement update

CDS (Jon) New spreadsheet: [Link here] KA has spare 4x CONTEC DO-32L-PE boards in the office Laser Fiber optics (Rana) low loss fiber modulator looks difficult to obtain Alternative option: RIO-> free space EO/AO -> Power amp LLO HP4S (Rana) RIO peripherals (Koji) Super polished 2” substrate for possible relay optics (Rana) Typically 12 week delivery RoC spec TBD Use optics quoting template / Make new spec sheet / Loose spec like AR100ppm Suspension - more SOSs and OSEMs from MIT (Koji) [ELOG 15267] Electronics (Koji/Rich) Talk to Hartmut

Lab maintenance: Are there any critical items to be monitored? Vacuum / N2 pressure - Chub and Jordan taking care right now Laser power

Physical presence at the 40m

Gautam was in the lab from ~9pm to ~4am on 3/18.

March 17, 2020 (Tue) Report

(KA) When you happen to come to the lab, you may feel like cleaning some common surfaces as well as your hands. The common surfaces mean: tables, keyboards, instrument keys, doorknobs, light switches, laser safety goggles, and so on.

I came in this afternoon and supplied some cleaning resources: Hand soap at the sink. Dish soap has already been at the sink (and beneath the sink) as usual. Disinfectant wet wipe at the control room.

I did some wiping off the tables, doorknobs, and keyboards of the ctrl machines. But it's far from perfect. So help yourself to use them to clean your circumstances. c.f. CDC guidance

Some notes: We have some alcohols in the yellow cabinet. Isopropanol in yellow squish bottles can be turned to some wiping liquid but need to dilute a bit with water. Acetone and Methanol are not suitable for cleaning. Methanol is toxic too. We want to preserve the liquids in the glass bottles.

Don't share the inner shoes. Stick with yours if you have. If not, use shoe covers.

Label your name on a favorite laser goggle for temporary personalization. Don't forget to wipe it occasionally.

Most of the work station jobs can be done from your laptop. If you need a physical console to be personalized, let us know. With the current density of the people in the lab, we could do it. Gautam wants to exclusively occupy pianosa console.

The CAD WS can be used via remote desktop. I listed the access info on https://secrets.ligo.org/secrets/ When you are going to occupy this PC, notify us about your estm. Duration of the use here.

Please share if you have any additional thoughts.

Physical presence at the 40m

Koji came in at 2:30 PM, left at 7:30 PM. Gautam another locking trial on Wed.

March 16, 2020 (Mon) Home works

Jon and Yehonathan ETMY Acromag: Start preparing the ETMY acromag unit. The setup can be mostly copied from the ETMX acromag. Yehonathan Elaborate Section 6.4 of the BHD requirement document to describe the angular coupling of the suspension, also considering the frequency response of the vibration isolation stack (T1900636). Describe these separately and explicitly: the source vibration, the coupling process, and the resulting noise. This will become a response to the BHD review. Gautam Sensing/Actuator noise estimation. Rich suggested for us to use D1002818 and D1100687 as the satellite amp and the coil driver. Calculate the sensing limit and the actuator noise level with them. The coil driver noise analysis by Luis can be found here: E1900347 Rich likely to have the noise analysis of the sat amp. We'd be able to get the source files of the analyses from them for the detailed noise budgeting. Gautam: I’m in touch with Rich regarding models/data he may have. I will post an update by March 18. Koji BHD electronics diagram: The draft is already uploaded as a dropbox file although it needs some checking of the actual setup. BHD optical layout BHD timeline update: As of March 15 (Dropbox)

BHD Procurement

Please proceed to procure the BHD parts. For now, we use our usual LOPS.FAC.LBSH.57.CIT account. The cost is going to be transferred to the new account once we get it.

CDS (Jon) Laser Fiber optics (Rana) LLO HP4S (Rana) RIO peripherals (Koji) Super polished 2” substrate for possible relay optics (Rana) Suspension - more SOSs and OSEMs from MIT (Koji) Electronics (Koji/Rich)

Physical presence at the 40m

Yehonathan worked on the arm ring down in the day time Gautam worked on locking in the evening

Gautam wants to continue to work on locking in the evening, but not every day. He comes in on 3/16 (Mon) evening. And again on 3/18 evening. Koji comes in on 3/17 (Tue) afternoon for the electronics wiring survey.

Yehonathan comes 3/16 (Mon) noon to continue Arm loss measurements and ETMY electronics survey. Jon. No immediate plans to come in. Will begin soliciting quotes for CDS hardware. Will also start creating the EPICS database for c1auxey once I receive the channel list from Yehonathan.