40m elog, Page 330 of 357
Not logged in
-- All entries --
Last 3 Days
Last 3 Months
Last 6 Months
-- Type --
Thu Apr 24 15:57:53 2008
Safety at AP-ISCT
I measured the output power of the psl after the mechanical shutter.
It was 1.1 W with Ophir power meter, than unlocked the MC and measured
the power at the MC-REFL Beam Dump at the AP-ISCT 0.9 W
Power on MC-REFL photodiode 92 mW
High power metal beam shields were installed around the beam path of
MC-REFL between AP-Viewport and MC-REFL Beam Dump.
Placed HIGH POWER LASER BEAM PATH warning signs on table frame and top
Last week I placed a small monitor on the top of the OOC that
monitors the resonant spot of MC2. Please keep an eye on this monitor
when working on the AP-ISCT
AP table should NOT be left uncovered. One experienced laser operator
has to be present if the top is removed and IR-viewer scan required.
We need your full cooperation to keep this lab safe.
Fri Apr 25 15:44:21 2008
In pursuit of a low back scattering, high power beam dump we looked at materials such:
polished copper, polished aluminum, diamond cut aluminum, variety of polished & heat treated stainless steel and shades of black glasses.
Black glass is ideal at low power. Superpolished SS 304 #8 is the only material that measures close to bg
We are still looking for a conductive low back scattering material that would be ideal for a good high power beam trap.
Black glass-shade 12, ss304 superpolished #8 and white paper-B98-24lbs back scattering were compared at 1064 nm
Atm 1: data plot numbers from front panel of SR830 display,
sensitivity: 1x1 mV for bg and ss
1x1 V for wp
Atm 2: drawing of measurement set up
Atm 3: SR830 lock.amp settings
Atm 4: view from steering mirror
Atm 5: view from black glass trap
Atm 6: white paper
Thu May 1 08:31:51 2008
earthquake trips etmy & mc1
Earthquake at Lake Isabel magnitude 4.4 at 1am today shakes the 40m
ETMY and MC1 watchdogs tripped.
Sus damping restored.
Mon May 5 15:53:14 2008
drypump replaced & readbacks are out
The small turbo pump of the annulus system is tp3
It's drypump was replaced at 1.4 Torr after 8 months of operation.
The rebuilding cost of this SH100 drypump is getting ridiculously high $1349.
I'll look for a replacement.
Joseph rebooted c1vac2 card on Apr 24 entry#441
This restarted the readbacks of the turbos and ion pumps for a while.
That was nice. The readbacks are not working again
Fri May 9 08:40:24 2008
ETMY sus damping restored
ETMY lost damping at 19:10 last night.
There was no seismic event than.
Sus damping was restored this morning.
Tue May 13 10:15:52 2008
restored damping of BS & PRM
I think our janitor was cleaning too heavy handedly.
The BS and PRM sus damping were lost.
They were restored.
Tue May 13 10:38:28 2008
rfm network is down
The RFM network went down yesterday around 5pm
Only c1susvme1 is alive but it's timing is off.
Andrey is bringing the network up.
Andrey wants to make an addition first that our situation is very much similar to that described by Rana in his elog entry # 353 (March 03). All of the rectangular boxes are red, except for SUS1-c1susvme1 and AWG (only these two rectangles are green).
Thu May 15 10:40:21 2008
Lisa Goggin, PhD
Lisa Goggin successfully defended her thesis on May, 13 2008
"A Search For Gravitational Waves from Perturbed Black Hole Ringdowns in Ligo Data"
She started out as a surf student in the 40m.
Mon May 19 11:49:57 2008
etmy oplev laser replaced
The 9 years old Uniphase HeNe was replaced by a new JDSU 1103P
Power output ~3.5 mW, reflected light back on qpd ~140 microW, 12,800 counts
Andrey will get the ~2.5 mm od spot on the qpd smaller by replacing
the f1000 lens
Tue May 20 09:28:42 2008
safety traning for 40m
Tara Chalernsongsak, new gradstudent for K. Libbrecht was introduced to the basics of the 40m operations.
Thu May 22 11:21:45 2008
early surf sudent
Caltech under grad Eric Mintun received the 40m safety training.
Now he has to read and sign SOP of laser and ifo.
He'll be working with GigE cameras with Joe
Wed May 28 14:19:47 2008
kaleidoscope of psl
atm 1: scattering psl table optics from the top of the output periscope f4, 60s @MOPA 3 W
atm 2: scattering psl table optics from the top of the output periscope f4, 20s
atm 3: competing GigE cameras on the north end of psl table
atm 4: yellow "soft" washer to be replaced on psl output periscope
atm 5: ETMY-ISCT in disarray
Thu May 29 16:32:09 2008
etmy oplev is back
I relayed the optics for ETMY-oplev as shown in pictures below.
The reflected beam goes directly to the qpd
Thu May 29 16:49:49 2008
Yoichi has arrived
Yoichi had his first 40m meeting. We welcomed him and Tobin, who is visiting, by sugar napoleons that
Wed Jun 4 10:18:52 2008
wedged SS beam trap
I moved the SS trap over to the psl table.
Texas super # 8 was used from the large shipment.
TXs#8 scattering measured as before, meaning the polishing is good.
Go's squeezing power pick up 350 mW was used.
I made two ~30 degrees wedge traps using 6" x 4" and 12" x 4" SS 0.039" thick
with copper backing of similar size.
There was too much scattering and I could not minimize them all.
It is very helpful to have so much space on the psl table.
It shows more of the weakness of this kind of trap.
I did not dare to turn up the power.
Fri Jun 6 15:56:00 2008
Yoichi received safety training
Yoichi Aso received 40m specific safety training.
Fri Jun 6 16:10:51 2008
HEPA filters are running at 100%
The psl HEPA filters were turned up to run at 100% to accommodate beam trap work on Tuesday, June 3, 2008
Tue Jun 10 08:37:18 2008
beam trap is being tested
High power beam trap is being tested just west of FSS area on psl enclosure.
When the pmc is operating at low power that means that the rest of the 3W is going into the
circular SS trap.
Please beware of the high power beam trap test
Wed Jun 11 11:45:25 2008
ss trap works
The trap works well at 3 W level. No back reflected beam coming out of the trap on low power
sensing card level. The back scattering was not measured. The trap is insensitive to small pointing variations.
The SS surface did not show any visible degradation after 16 hrs of 3w exposure at elliptical beam size 4x8 mm
It is ready to be placed into the 35 W beam.
Fri Jun 20 17:42:48 2008
SS trap scattering compared to black glass trap
Circular SS304 trap was compared to wedged black glass trap.
The measurement set up of entry 529 was changed to define polarization.
CrystaLaser was remounted in horizontal position and half wave plate was placed after it.
These measurements were done in horizontal polarization.
atm1: the cSSt and wBGt was moved horizontally, ~90 degrees of the incident beam
atm2: traps were rotated around the incident beam, ~20 degrees each direction
atm3: set up
atm4: top view of traps
atm5: side view of trap
Fri Jun 27 09:20:15 2008
dust particle count is up & alarm handler is on
This 3 years plot show the trend of seasons.
When outside air quality goes bad ( 0.5 micron > 1 million ) the lab follows.
I will demonstrate this effect with a 4th of July fire works calibration.
Let's do not forget the construction activity next door either.
The alarm handler is busy:
It's sound level were reset to a modest level yesterday.
It would be nice to change the alarm sound so it can play Wagner:Der Ring des Nibelungen:
Das Rheingold, Die Walkure & Siegfried and Gotterdammerung
or something more appropriate than the present frog call
1, half micron count is climbing ( it's close to 16k now )
2, MZ refl signal is too high
3, MC lenght servo LO is too
Mon Jun 30 08:59:23 2008
IOO-MC_DEMOD_LO is low
The alarm handler is beeping relentlessly: asking for help in high partical count and low demod signal
Tue Jul 1 09:26:33 2008
RFM network is down
Tue Jul 1 10:15:22 2008
eventfull two days
The laser recovered from a short temp rise. The MZ was aligned and realigned. The suspentions were kicked up accidentally.
Now the computers are down.
Wed Jul 2 15:14:42 2008
added beam traps
I placed baked razor beam trap after INJ_SM1 and flipper in the injection path on the AP table
I have constructed the beam injection optics for the abs length measurement.
The injection beam was coarsely aligned to the interferometer. The reflected beam from SRM was already seen at AS CCD.
I have attached the optical configration for this measurement and the optics layout at the AP table.
I am going to go to LHO for three weeks. During the absence Alberto tunes the mode matching and the alignment of the interferometer.
In the process of making this report, I noticed that one of the iris apertures is about disturbing the beam for OMCR CCD. I will check this before I go to Hanford. Also an RF spectrum analyzer is at the AP table. I try to return this near the PSL on Monday morning.
Attachment 1: Optical configuration for the abs length measurement.
1) One of the arms is locked to the PSL beam by the main control system
2) A laser beam is injected from the AS port
. This laser essentially has different frequency from that of PSL.
3) The injected beam and the outgoing PSL beam appear at the output of the faraday in the injection system.
4) They beat each other at the frequency difference of those two lasers.
5) A PLL is used to lock the frequency difference to a local oscillator (LO).
6) The LO frequency is swept at around 3.87MHz, that is the approximate FSR frequency of the arm cavity.
7) If the LO frequency hits the FSR within the resonant width, the beating also appears at the transmitted light as the injected beam also becomes resonant to the arm cavity.
8) Amplitude of the beating at the transmitted light is measured by a RF spectrum analyzer as a function of the LO frequency. We get the FSR frequency (= the arm cavity length) from the top of the resonance.
Attachment 2: Optics at the AP table for the laser injection
, laser source. vertically polarized.
, to raise the beam 1 inch to make the beam at the 4 inch elevation.
, steering mirrors to align the injection beam to the IFO beam.
, half wave plate to make the beam to the farady horiz-polarized. nominal 42deg on the readout.
, Faraday isolator for protection of the NPRO from the returning light, for obtaining the returning light.
, to make the beam from the Faraday horiz-polarized. nominal 357deg on the readout.
, f=125mm to match the laser mode to the IFO beam.
, steering mirrors to align the IFO beam to the Farady Isolator.
, for the coarse alignment of the injection beam.
, flipper mount to turn on/off the injection optics.
Alignment procedure of the injection system
0) Ignite NPRO several hours before the experiment so that the laser frequency can be stable.
1) Turn up FLIP. Close the shutter of NPRO.
2) Adjust SM1/SM2 so that the ifo beam can appear at the output of FI.
3) Adjust height and position of IRIS1/IRIS2 with regard to the ifo beam so that the ifo beam goes through IRIS1/IRIS2 even when they are closed.
4) Turn down FLIP. Open the shutter of NPRO.
5) Adjust INJ_SM1/INJ_SM2 so that the injection beam can go through IRIS1/IRIS2 even when they are closed.
6) At this time, it is expected that the reflection of the injection beam from SRM appears at AS CCD, if SRM is aligned.
7) Adjust INJ_SM1/INJ_SM2 so that the injection beam at AS CCD can overlap to the IFO beam.
8) Confirm the beam at the output of the FI also overlaps.
---- We are here ----
9) Change the ifo configuration to the X or Y arm only.
10) Scan the crystal temperature of the 700mW NPRO in order to try to have the beating of the two beams at the PD. AS OSA may be useful to obtain the beating.
11) Once the beating is obtained, adjust INJ_SM1/INJ_SM2 such that the beating amplitude is maximized.
Mon Jul 7 16:30:08 2008
PSL-PEM 16 days trend
This morning the laser head temp was up to 20.3C because the laser chiller was overflowing.
I removed 700 cc water.
The PSL-FSS_RMTEMP became much more stable during the holidays as the psl enclosure was closed for 4 days
The high particle counts can be explaned by construction activity today.
The PMC & MZ PZT high voltages were out of range this morning.
Tue Jul 8 08:16:56 2008
The PMC is unhappy. PMC auto locker is not working.
DC output slider adjust has to be moved from rail to rail before it locks.
MZ is working great.
Tue Jul 8 10:20:10 2008
HEPA turned on
It is specially important to run the PSL-HEPA filters when inside counts is peaking at 30,000 counts
There is a small label at the hepa on/off switch:
enclosure open 100%,
low noise off,
normal 60% of Variac voltage setting on the top of the enclosure
Not running the HEPAs will lower the temp fluctuations from 1.5 to o.5 degree C
at the cost of particle counts from 0 to immidiate room counts.
Wed Jul 9 15:04:22 2008
SURFs helping hands
Surf students are helping out with baffle cleaning.
Fri Jul 11 09:29:02 2008
the PMC still hangs up
PMC high voltage is railing, it's auto locker is frosen
I have to move DC Output Adjust slider by hand and it locks immediately
PSL_ISS is saturating. Saturation goes away when PMC is locked.
Laser chiller water is overflowing again: removed 450 cc water
Tue Jul 15 09:47:09 2008
lab temps and particles
All air condtion units were serviced last Friday.
AC filters are trying to control our particle counts but they have no capacity to match bad Pasadena conditions.
IFO room filters at CES were really clean.
Air make up filters inside and outside were dirty.
They showed the construction effect.
Control room and clean assembly units needed all filters replaced.
Note: the PSL-FSS_RCTEMP droped o.1C when enclouser HEPAs were turned back on
The RC temp controller should be better than that!
Tue Jul 15 10:24:57 2008
PMC temp & pzt voltage
The PMC pzt HV was happy with no HEPA temp stability.
Can we thermally insulate the pmc ?
Wed Jul 16 09:27:17 2008
PSL-FSS_RMTEMP alarm is false
Morning alarm sound is good for people who does not drink coffee.
Our 40m alarm is on every morning.
Those whom are not here in the morning thinks that this beeping sound is inspirational.
Would someone change this sound into less punishing form, like mockingbird chirp....
The C1PSL_SETTINGS.adl (40mm PSL Settings ) indicating that
C1:PSL-FSS_INOFFSET (Input Offset Adjust ) should be 0.3 +-0.05 V (red warning tag )
Alarm Handler: 40M pointing to yellow grade warning of PSL-FSS_RMTEM
This is a false alarm.
Two years trend of these channels are here:
Thu Jul 17 08:30:15 2008
PMC relocked manually
The PMC pzt HV and the servo gain adj. are railing at max this morning
Why is it on the decreasing side of FSS_RTTEMP slope?
Mon Jul 21 10:00:42 2008
ifo room temp
Five years of temp trend with 5 C fluctuation. The campus chilled water supply was upgraded ~ 1 year ago.
I requested our thermostats to be calibrated.
Mon Jul 21 15:52:22 2008
fire alarms test
The fire alarm test and evacuation drill was successfully completed at 13:45 Wednesday, July 16, 2008
Everybody was on time for the 40m meeting.
Tue Jul 22 09:24:17 2008
Laser power reality of 120 days
Tue Jul 22 16:50:09 2008
professorial clean up of work bench
Atm1: is showing the spiritual satisfaction after work bench clean up by the professor himself.
Atm2: some items are still waiting to be placed back to their location
Mon Aug 4 12:12:20 2008
the ifo is at atm
The 40m vac envelope was vented this morning.
P1 is at 760 Torr
Tue Aug 5 10:23:00 2008
earthquake and venting effects
atm 1, EQ
atm 2, vent 7 days later: venting kicks optic into place to be free,
PRM: LR magnet gets pushed in and it is stocked, side in free
Wed Aug 13 17:00:59 2008
BS sat amp removed
The PRM sat amp is broken. Ben is working on it.
The BS sat amp was removed from the BS sus and it is used with the PRM in
order to damp it for wire stand-off alignment.
Thu Aug 14 10:26:45 2008
sus cable pin cheater for out of vac damping
The 40m D25 vacuum feed troughs give you a mirror image pin count.
Sus damping outside of the vacuum envelope require this cheater cable where
on the male D pin 1 is connected to female D 13 and so on
and male D pin 14 is connected to female D 25 and so on
Thu Aug 14 11:39:06 2008
particle counter is out of order
The 40m ifo paricle counter sensor failed last night.
Fri Aug 15 14:12:31 2008
safety glasses required
The MOPA shutter is opened,
the PSL enclosure is switched to bypass mode,
manual block removed from PMC,
the PSL output is still blocked and the mechanical shutter is still closed.
Pumpdown is at 300 Torr continuing
Laser safety glasses are required!
Fri Aug 15 19:32:49 2008
I have just reached vacuum normal. The maglev peaked at 49.8C body temp with aux fan on at 3.2 Torr
note: pumpdown was put on hold for Koji's goodby lunch
Mon Aug 18 09:19:55 2008
11 days at atm
It took 11 days to fix earth quake triggered sus problems of ITMX, SRM and PRM
Only ITMX north and BSC north vac doors were removed.
The PRM sus had to be removed form the vac envelope for "hip replacement"-new wire stand off was
epoxied in place.
Note: the PRM has no guide rod on the other side
ITMX, SRM and BS osems were optimized in place.
No crosscoupling optimization was performed.
Beam block was removed from ITMXC, it was too close to the main beam.
POX pick off mirror and mount will be replaced next vent.
Vac viewports were inspected from the inside.
Thu Aug 21 10:24:20 2008
laser safe mode condition
The MOPA and PSL shutters are closed.
Manual beam blocks are in place.
Enclosure interlock is enabled.
No other high power laser is in operation.
We are in laser safe of operation for visiting students from Japan
NO safety glasses required
Thu Aug 21 16:28:59 2008
safety glasses required
I just opened the MOPA shutter so PA is warming up.
High power beam path is cleared and laser safety glasses required.
Fri Aug 22 16:06:29 2008
particle counter replaced, flowbenches & HEPAs checked
MetOne #2 counter was swapped in (on the top of IOC, facing SW direction, at ~75 deg upwards)
with channel one size 0.3 micron and channel two size 1.0 micron.
Sampling time was reduced from 60s to 6 sec at 0.1 cf/min at 25 min rate.
This means that displayed number needs to be multiplied by x100 to get particles/cf/min
HEPA filters and flow benches were checked:
PSL enclosure closed, HEPA speed at 60% 0-0 particles on optical table NW corner
AP covered optical table 1,000 particles of 0.3micron and 10 of 1.0 micron at NE corner
Flow bench at SE 0-0 particle (p)
on the top of SP cover at SE corner 60,000 p of 0.3 micron and 530 p of 1.0 micron
Mobile HEPAs 10cm from output screen in the center 800 p of 0.3 micron and 0 p of 1 micron
These filters will be replaced.
Clean assembly room:
both flow benches 0-0 p for 0.3-1.0 micron
east side bench 520 p of 0.3 micron and 210 p of 1.0 micron
Large hood in baking room with fan on 1.7 million p of 0.3 micron
and 16,000 p of 1.0 micron
Pasadena air just outside of main entrance:
3 million p of 0.3 micron and 30,000 p of 1.0 micron
My desk 743,000 p of 0.3micron, 63,000 p of 0.5 micron and 5,500 p of 1.0 micron cf/min
NOTE: existing COCHECKLIST.adl PEM displays needs to be corrected so it shows the 10 fold increase
and change particle size on this screen to 0.3 micron
Mon Aug 25 10:23:53 2008
Rack 1Y7 double violation:
BNC cables left to be jammed by door
and see destroyed BNCs
RED fibers should be rerouted.
I placed protective obstacle in position
so the door can not be closed.
Please do not do this!
DNA analysis is in progress on your finger prints.