1) Annalisa is going to start  working on mode profiling and beat note search for the old MOPA NPRO.

2) In the meantime, Manasa is working on the end table items. This will be reviewed by KA in the afternoon.

The laser at ATF is moved to the 40m when the status of 1) and 2) is determined by KA to be reasonable.

We also make the beat note measurement for the ATF laser too.
 

Today I installed mirrors to steer the pick-off from the main laser beam in a more free part of the PSL table and make the beat note measurement between it and the NPRO.

At the beginning I took the beam from the harmonic separator after the doubling crystal, and I was going to bring it in a less full part of the table . At the end I realized that there was already a beam steered up to a more free part of the table, and the beam is taken from the transmission of the PMC.

Tomorrow I'm going to use that beam to find the beat note with the NPRO.

I also removed almost all the steering  optics that I used on the ITMY table to send the auxiliary beam for ABSL through the window parallel to the POY beam. The most important thing is that I removed the BS, which was on the same path of the POY beam (see elog 8257).

[Koji, Annalisa, Manasa]

NPRO with controller from ATF joins the 40m. We have put it on the POY table where we plan to use it for ABSL.

Don't leave your food on tables and desks!

Also I put the souvenir chocolates in the microwave, just in case.

Just in case there was some confusion, the champagne on my desk is not to be opened before I get back, no matter how many signals are transitioned to RF.

At wednesday's meeting, Rana, Koji, Steve, and I started making a list of maintenence tasks that should be done/checked on a regular basis. The actual scheduling of these has not yet been considered. They include:

• N2 Tank pressure / cylinder replacement
• Headlamp, walkie talkie battery recharge
• Workstation software updates
• Coffee bean and filters
• Multimeter battery levels
• Sorensen DC power supply voltage settings and current draws
• UPS' status (Vacuum, NFS host, workstations)
• SR560s, battery powered scopes plugged in
• Rack Fuses intact
• Take pictures of electronics racks, optical tables
• Replace PSL HEPA filter

Next, we brainstormed work that can be done to improve the interferometer performance, and what order/precedence they should take. 

In the end, it was decided that the plan for the next few weeks was to focus on improving the ALS noise levels, and, more importantly, seeking to make the performance more consistent. We need to know what is limiting us, and what we extent we can expect to improve things. To this end, I am working on reviving a ALS noise budget; using the noise budget from the green locking paper to inform a simulinkNB kind of thing.

Here are all of the items we listed during this brainstorming session.

Some near-term/priority tasks are:

• Installing the accelerometers near MC1 and 2
• Installing green steering PZT mirrors at the Y end table, commission dither alignment
• Improving the X end green mode matching
• ALS noise budgeting
• Upgrade the realtime system to RCG v2.9

More down the line, other things we thought about were:

• Cleanup of bench power supplies (FSS box has one, where else?)
• Fixing the ETMX suspension issues 
• Upgrade SOS suspension code to the appropriate aLIGO block
• Upgrade to the green PDH electronics
• Understanding / tuning the FSS servo laser PZT vs. PC crossover
• Undestanding / tuning the 11MHz vs 55MHz modulation phase
• Replacing the slow vxworks machines with the Acromag setup Aiden has set up for the CTN lab
• QPD upgrade
• New/better green beatbox
• Finalize the manifestation of the IR beat control (Freq counter vs. fast DFD)
• Explore the idea of using an analog output of the ALS beatbox as fast input to the CM board
• Replace triple resonant EOM driving circuit with double resonant one
• X end table layout/enclosure upgrade

PZT Buzzer Box (Thorlabs HV Supply + Manual + 2*PZT Buzzers) ---> Cryo Lab (Brittany + Aaron)

Property tag found.

I brought a bunch of SR560s over for repair from Bridge labs. This unit, picture attached (SN 49698), appears to still not be retaining charge. I’ve brought it back. 

While Keerthana and johannes were working at the end, I made a little cleaning at the yend. I salvaged large amount of hardware inclding optics, optomechanics. We all together should work on returning them to appropriate locations.

Steve mentioned two unlabelled optics were found at EX, relics from the Endtable upgrade.

• One was a 1" 45 deg p-pol optic (Y1-1025-C-45P), it looks a bit scratched.
• The other was a Beam Sampler (BSF10-C).

These are now labelled and forked down on the SP table.

Koji's collection of Yend components put away. I cleaned up the  Xend bench today.

Loadcells, leveling wedge mounts  and related items placed under flowbench cabinet next to Guralp staff.

The cabeling was cleaned up a little bit yesterday morning. The upper back side is still massy.

EDIT: After discussing with Koji and checking the existing M2ISS PDs I put the two C30642G back and took two C30665GH (active diameter: 3mm) diodes. Only one of this type remains in storage.

I removed two C30642G photodiodes from the stash for the new M2ISS hardware and updated the wiki page accordingly.

I've taken a PI Piezo Actuator (P-810.10) from the 40m collection. I forgot to note it on the equipment checklist by the door, will do so when I next drop by.

Apr 16, 2019
Borrowed two laser goggles from the 40m. (Returned Apr 29, 2019)
Apr 19, 2019
Borrowed from the 40m:
- Universal camera mount
- 50mm CCD lens
- zoom CCD lens (Returned Apr 29, 2019)
- Olympus SP-570UZ (Returned Apr 29, 2019)
- Special Olympus USB Cable (Returned Apr 29, 2019)

I've borrowed the Busby Box for a day or so.  Location: QIL lab at Bridge West.

Edit  Sat Apr 20 21:16:46 2019 (awade): returned.

Borrowed Zurich HF2LI Lock in Amplifer to QIL lab Wed Apr 24 11:25:11 2019.

vanna --> QIL.

gautam 20190804: The GPIB module + power supply were returned to me by Duo ~5pm today at the 40m.

Mr Fred Goodbar of Konacrane was in the lab 830am-1130am today. All three cranes in the VEA were inspected, loaded with 450lb test weights, and declared in good working condition and safe to use.

1. Apparently, the clackity noise heard when running the crane at the south end is a known problem - the crane was opened up and inspected sometime in the past, and no obvious cause was found. This is not expected to affect the usability of the crane.
2. The travel speed of the cranes is slow - but this is apparently intentional, on the request of Steve V.

The interferometer subsystems appear normal after the inspection. 

I have received the new screwdriver bits that will work with the two electric screwdrivers we have. I have distributed them in the 40m. Some are in the electronics stations and some are in the toolbox in the lab. The new electric screwdriver (which looks like a drill but takes typical screwdriver bits) is in the room with the workshop. It is in the blue Makita box. For some reason, lots of the old bits were rounded because of incorrect use. I have thrown the unuseable ones out.

I also requested some screw extractors in case we need them. the one we have now is really big and may not work on smaller screws.

During the cleaning today, we found many legacy lab items. Here are some policies what should be kept / what should be disposed

Dispose

• VME crates and VME electronics as long as they are not in use
• Eurocard SUS modules that are not in use.
• Eurocard crates (until we remove the last Eurocard module from the lab)
• Giant steel plate/palette (like a fork lift palette) along the Y arm. (Attachment 1)
• An overhead projector unit.

Keep

• Spare Eurocard crates / ISC/PZT Eurocard modules
• Boxes of old 40m logbooks behind the Y arm (see Attachment 2/3).
• Ink-plotter time-series data (paper rolls) of 1996 IFO locking (Attachment 4). Now stored in a logbook box.
• A/V type remnants: Video tapes / video cameras / casette tapes as long as they hold some information in it. i.e. Blank tapes/blank paper rolls can be disposed.

FPMI related
- Better suspension damping HIGH
 - Investigate ITMX input matrix diagonalization (40m/16931)
 - Output matrix diagonalization
 * FPMI lock is not stable, only lasts a few minutes for so. MICH fringe is too fast; 5-10 fringes/sec in the evening.
- Noise budget HIGH
 - Calibrate error signals (actually already done with sensing matrix measurement 40m/17069)
 - Make a sensitivity curve using error and feedback signals (actuator calibration 40m/16978)
 * See if optical gain and actuation efficiency makes sense. REFL55 error signal amplitude is sensitive to cable connections.
- FPMI locking
 - Use CARM/DARM filters, not XARM/YARM filters
 - Remove FM4 belly
 - Automate lock acquisition procedure
- Initial alignment scheme
 - Investigate which suspension drifts much
 - Scheme compatible with BHD alignment
 * These days, we have to align almost from scratch every morning. Empirically, TT2 seems to recover LO alignment and PR2/3 seems to recover Yarm alignment (40m/17056). Xarm seems to be stable.
- ALS
 - Install alignment PZTs for Yarm
 - Restore ALS CARM and DARM
 * Green seems to be useful also for initial alignment of IR to see if arms drifted or not (40m/17056).
- ASS
 - Suspension output matrix diagonalization to minimize pitch-yaw coupling (current output matrix is pitch-yaw coupled 40m/16915)
 - Balance ITM and ETM actuation first so that ASS loops will be understandable (40m/17014)
- Suspension calibrations
 - Calibrate oplevs
 - Calibrate SUSPOS/PIT/YAW/SIDE signals (40m/16898)
 * We need better understanding of suspension motions. Also good for A2L noise budgeting.
- CARM servo with Common Mode Board
 - Do it with single arm first

BHD related
- Better suspension damping HIGH
 - Invesitage LO2 input matrix diagonalization (40m/16931)
 - Output matrix diagonalization (almost all new suspensions 40m/17073)
 * BHD fringe speed is too fast (~100 fringes/sec?), LO phase locking saturates (40m/17037).
- LO phase locking
 - With better suspensions
 - Measure open loop transfer function
 - Try dither lock with dithering LO or AS with MICH offset (single modulation)
 - Modify c1hpc/c1lsc so that it can modulate BS and do double demodulation, and try double demodulation
- Noise Budget HIGH
 - Calibrate MICH error signal and AS-LO fringe
 - Calibrate LO1, LO2, AS1, AS4 actuation using ITM single bounce - LO fringe
 - Check BHD DCPD signal chain (DCPD making negative output when fringes are too fast; 40m/17067)
 - Make a sensitivity curve using error and feedback signals
- AS-LO mode-matching 
 - Model what could be causing funny LO shape
 - Model if having low mode-matching is bad or not
 * Measured mode-matching of 56% sounds too low to explain with errors in mode-matching telescope (40m/16859, 40m/17067).

IMC related
- WFS loops too fast (40m/17061)
- Noise Budget
- Investigate MC3 damping (40m/17073)
- MC2 length control path

• ETMX damping loops are not good. ETMX is moving by ~10 urad (if oplev is correctly calibrated), and beam spot moves by ~0.5 beam spot on ETMX when Xarm is locked. TRX fluctuates by ~10%. Simply tuning gains did not solve.
• ETMX does not come back after putting some offset to misalign and remove the offset to align. Hysterisis makes me hysteric.
• Xend acromag is removed, and we cannot access Xend shutter and ETMX slow channels.
• XARM ASS is not working.
• Yend laser is not working.

• ND10 and ND20 neutral density filter
  
• EOM and mount set for 4 inch beam height
  
• Post for fiber launch to get to 4 inch
  
• Mode matching lens at 4in
  
• 3x steering mirror at 4in
  
• RF photodiode at 4in
  
• Post for camera to 4in
  
• Light sheild for camera
  
• Long BNC cable
  

MC1     28.21625 kHz
MC2     28.036   kHz
MC3     28.21637 kHz