I have realigned the beam pointing to PMC. The transmitted light increased from 0.74 to 0.83.
The misalignment was mainly in pitch.
The PMC pointing has changed, so MC is resonating in high order modes.
Roscolux filter films #74 night blue, 0.003" thick and #26 light red, 0.002" thick were measured in the beam path of ~6 mm diameter, 1W 1064 nm .
T 90% + - 5% at 0-30 degrees of incident angles and R ~10 %
These sandwitched thin films of policarbonate-polyester filters are not available in thicker forms. Rosco is recommending them to be cooled by air if used in high power beam.
These filters did not get warm at all in 1W, so absorption must be very small.
The 2W Innilight shutdown shut when I opened side door for safety scan. This was not a repeatable by opening -closing side doors later on. Turned laser on, locked PMC and MC locked instantly. The MC was not locked this moring and it seemed that the MC2 spot was still some high order mode
like yesterday. MC lock was lost when the janitor bumped something around the MC.
The 2W PSL laser is turned off. The danger laser lights are not illuminated at the entry doors because of malfunctioning electronic circuit!!!
Laser safety glasses are still required! Other lasers are in operation!
BEN fixed the interlock. The laser is turned ON. Thanks for all, Rich and Sam who came over to help. Atm1
All emergency shut- off switches, lights and door indicators are working at this moment. More about this tomorrow.
Atm2, PSL enclosure interlock jungle without REAL schematic drawing.....at this point.... We all agreed it is easier to redo the hole thing than find the problem
Atm3, Emergency shut off switches and illuminated signs from entry doors to AC on-off box ( Use this switches in emergency ONLY, otherwise leave alone , even it is labeled obsolete !)
Summery: I still do not really know what was wrong.
Rough draft of updated interlock drawing by Ben is here.
Cold LED lights replaced hot halogen ones. Flat LED MYAL 6S, model #112560002 24VAC
This is a LATE ENTRY. They were purchased in Jan 2010 and installed 6 of them around May 2010
Schott, green welding glass, shade 14, 3 mm thick was measured in the beam path of 1.2W, S polarization of 1064nm at ~1 mm diameter size as MC reflected path.
Absorption 95%, R 5% at incident angle 25-50 degrees. It looks like the perfect material for beam trap.
The attached trend shows a problem with the QPD sums.
Steve - please check on Monday the laser powers and the ETM/ITM reflectivity for HeNe lasers. Maybe we have to increase the transimpedance gain in the heads.
ETMX and ETMY have 0.2 mW returning to their QPDs........so the gain must lower at ETMX
ITMX laser 1103P has only 0.67 mW output and 0.025 mW returning to the QPD.
ITMX and ETMX oplev lanching paths have lenses without AR coating. This is my fault. I will buy them.
ETMX 0.2 mW 900 counts
ITMX 0.025 1300
SRM 0.04 2600
BS 0.05 3500
PRM 0.06 4000
ETMY 0.2 9000
ITMY 0.3 14500
Kiwamu showed me how to do transferfunction of oplev pitch
SUS- BS, ITMX, ITMY, PRM, SRM, ETMX & ETMY_OLPIT transfer funtion with sine wave excitation 0.1 amplitude:
I'm driving C1:SUS-ITMX_OLYAW and PIT_EXC with amplitude 0,1-0.3 while taking transfer funtions of oplev.
The transfer functions are normal. However I noticed that the LL osem is not responding to this excitations
Healthy sensor respons should be like Atm3
OL_YAW transfer functions are here.
I had two PHDs helping me to overlap the EXML files in DTT. We failed. This job requires professorial help.
These observations of the OSEMs were taken while taking transfer functions of oplev YAW at excitation amplitude 0.1
Atm1, C1:SUS-ETMX_SENSOR_SIDE cross coupling
Atm2, C1:SUS-ITMX_SENSOR_LL not excitable
Atm3-4, BS and PRM insensitive
Good OSEM list: ITMY, ETMY and SRM
I gave up tonight's locking activity because the MC can't stay locked.
It seems that somehow the seismic noise became louder from about 1:00 AM.
I walked around the outside of the 40-m building to see what's going on, but no one was jumping or partying.
I am leaving the MC autolocker disabled so that the laser won't be driven crazy and the WFS won't kick the MC suspensions.
The attachment is a 3-hour trend of the seismometer outputs and the MC trans.
Something has started shaking last night. Everybody is claiming to be innocent next door.
I turned off the 40m AC at 11:06
The shaking has stopped at 9:32am The AC was turned back on at 11:30am We still do not have any explanation
Finally I found a company who can do Koji's improved -hard to make- specification on ruby or sapphire wire standoff.
NOT POLISHED excimer laser cut, wire groove radius R 0.0005" + - 0.0002"
$250 ea at 50 pieces of order
The air cond was off for 2 hrs. I just switched it back on at 15:51
ITMX, PRM and BS watchdogs are tripped. They were restored.
Stable MC was disabled so I can use MC_REFL 1 W beam to measure green glass .
Schott, Athermal green welding glass, shade #14 reflectivity was measured in 1.2W, ~1 mm diameter beam of MC reflected.
The P polarization measurement was done with the help of half wave plate and PBC
I added an U channel based bottom shelf at the south end today.
Initial pointing or IP-ANG is a pointing monitor of the MC. This beam is launched after the second pzt steering mirror.
IP-ANG is missing the pick up mirror by a few inches at ETMYchamber
1000 days plot show last appearance in Feb 2010
Two extender plates ready for cleaning. The existing optical table tops have 38" OD. Using two of these the OD will be 44"
Emergency exit lights were inspected: 2 out of 13 batteries have to be replaced
One of the Halon fire extinguishers needs to be recharged out of 8
Please do participate in preparation for the upcoming safety audit on Feb 28
Oplev transfer functions PIT UGF were optimized to be at 2-3 Hz with 60 degree minimum phase margin by adjuting oplev gains.
Additional Notes by KI:
Kiwamu (or whoever is here last tonight): please run the free-swing/kick script (/opt/rtcds/caltech/c1/scripts/SUS/freeswing) before you leave, and I'll check the matrices and update the suspensions tomorrow morning.
All suspentions were restored and MC locked. PRM side osem RMS motion was high.
Atm2, Why the PRM is 2x as noisy as the SRM ?
Batteries replaced and cylinder recharged. Please clean up your experimental set up if it is blocking breakers or entry way etc.
I will start the final clean up 2pm today.
The BS and the PRM have 3.3 Hz resonant gain filters that kill the phase margins.
Correction list by visiting safety committee, Haick Issaian is not shown:
1, update laser, crane operator list and post it
2, check fire extinguishers monthly, date and initials must be on the tags
3, move drinking water tower so it does not block fire extinguisher
4, post updated crane doc at cranes
5, post present phone lists at IFO room phones
6, emergency laser shutoff at the south end must be mounted without C-clamp
7, use heavy cable tie to insure position of mag-fan on cabinet top
Additional to do list:
a, safety glasses to be cleaned
b, let the electrical shop fix Rack-AC power to optical tables at the ends
c, measure transmission of laser safety glasses
d, update IFO outside door info signs
e, update laser inventory and post it
f, schedule annual crane inspection and renew maintenance contract
g, PSL enclosure inner shelf needs a good clean up so it is earthquake safe
Green welding glass 7" x 9" shade #14 with 40 mm hole and mounting fixtures are ready to reduce scatter light on SOS
PEEK 450CA shims and U-shaped clips will keep these plates damped.
All oplev qpd quadrons were zeroed by offset in blocked dark condition.
Type: How not to
Please do not leave optical tables open! You will be held responsible for creating dirty optics.
Optical spectrum analyzers like the Attachment made by Coherent , Meles Griot- CVI and Spectral Product are all discontinued.
The 40m have Coherent models C240 analyzer with controller C251 Their Finesse measured in 2004: sn205408 F302, sn205409 F396,
Jenne borrowed Jan's Meles Griot model 13SAE006, Peter King has the same model. FSR 300 MHZ, finnees 200 minimum
Over-sized local laser emergency switch was held by large C clamp at the south end. This was replaced by a smaller one and it is mounted with magnets.
The Innolight laser was turned off, while the interlock was wired.
Dichroic mirror quotes are in the wiki.
ATF is pricy.
We got a good price from Laseroptik, but the wedges are 5 arcminutes. The fused silica grade is 0F, meaning the homogeneity is 5 ppm instead of 1ppm. I requested an other large wedge quote on the substrates.We may have to get substrates from somebody else and ship it to Germany
MLT quote is outrageously high
REO is not interested in this low volume job.
Today is janitor day. It still does not explain why the 2W Innolight tripped off about an hour ago. All back to normal.
.......................................................I asked Keven later, he admitted hitting the emergency shut off next to the chemical storage cabinet.
Fred Goodbar of Konecrane has completed the annual certified crane inspection and maintenance of our cranes as required in safety document.
They are in good working condition and safe to use.
ETMY sus damping was disabled. Green locking laser and associated electronics turned off. Computers and power supplies turned off at rack 1Y4
The electricians picking up ac power from 1Y4 manual disconnect box and installing conduit line to ISCT-ETMY east end optical table.
There will be no more daisy chaining this way.
The power is back on at ETMY . c1iscey has not been restarted.
Now I'm turning ac power off at ETMX for the same job to be done.
The power was turned back on at 4pm It took some time for Suresh to restart the computers. We have damping but things are not perfect yet. Auto BURTH did not work well.
The Laseroptik quote is here.The 2 degrees wedge cost is $40 on each optics! See wiki
Bob cleaned all safety glasses in 10 % Liquinox soap in water solution first. The transmittance of glasses were checked at 100 mW 1064 nm S polarization, beam diameter 0.5 mm at 0-20 deg incident.
Coherent FieldMate power meter measured T= < 1 mW of all glasses.
Completed with the exception of d and g
Our existing 300 series SS plungers from McMastercar #8476A43 are silver plated as Atm2 shows.
Problems: 1, they become magnetized after years being close to the magnets
2, they oxidize by time so it is hard to turn them
I looked around to replace them.
Titanium body, nose and beryllium copper spring. None magnetic for UHV enviorment.
Can be made in 7 weeks at an UNREASONABLE $169.00 ea at quantity of 50
In order to get a better price from Vlier's Tom Chen I changed Ti body back to SS304L-siver plated and music wire spring. The price is still ~$120 ea. at quantity 50
I will talk to Mike G about modifying the McMaster plunger with a hex nut.
Conclusion: There is no need to silver plate the SS plunger at the torque level we hold the OSEMs
Mike Gerfen will be done with 50 pieces by April 4 and he will give them to Bob for cleaning. They should be cleaned and baked in a jig so the springs would be compressed for better venting.
The CIT Chemistry Glass Shop cuts turned out to be sloppy using diamond disc blade cutter.
East coast Precision Glass & Optics offered scribed cut and polished side. Their quote price was high and time consuming.
The GLASS HOUSE shop in Pasadena 626 / 796-9151 on Walnut did a good and cheap job. Oscar the cutter will finish the rest of the cutting by next Friday, April 6
He used scribed cutting technic and his 1" x 0.5" pieces are good. Bob will pick up them up.
Local eq shakes the lab
We received 6 new chairs stools for the work benches that have 36" heights.
The control room east side and general office desks require 18" seat height. The new chairs stools have minimum seat heights 26"
Please label chairs that we are getting rid of.
I'm working on similar shelf at ETMY. Precondition: NPRO in bypass mode, heater for doubling in bypass........since power outage? Optical level servo turned off.......
U-channel based shelf in place. Oplev servo is back on at 11:15am The table may moved. The oplev return is missing the quad by a few milimeter.
ETMY sus damping restored.