ITMY side : Magnet od 1.9 mm so wire to magnet gap ~ 0.2-0.3 mm
Thanks for checking this out Koji
The builder in 1996 was Process System International, Inc ( Westborough, MA ) It does not exist any longer or I just could not find them. Flow diagramm at Atm1
Should I be keep looking for a company who could quote us for building a similar smaller unit with 10 - 15 cfm flowrate?
Note: my intension with the two mobile-overhead HEPA filter was the same as John Worden's " clean air overpressured tent " at chamber entrance.
Atm2, Our unit has 650 cfm, velocity 90 fpm at resistance 0.5" It may be enough to give a little overpressure if we seal it well to the chamber
We use to use them to minimize dirt getting inside the chanbers.
The clamp is in the machine for milling off the grooves. It's condition is normal. The edges needs some 800 sand paper so it is not sharp anywhere.
How did those nicks get on the edge? Fortunatelly they did not aligned with the wire.
Unbaked steel music wire from "Ca Fine Wire Co" from 24" od spool, od 0.0017" used. Identical to the one that broke.
The set up as shown with silver plated screws-washers on clamp. The unused clamp edges were sanded on P800 paper at 45 degrees just not to be very sharp.
Use your finger to feel the sharpness of edge and sand till it gets a little bit not so sharp. The drawing note is "sharp edges" on wire clamp for low loss, high Q in mind.
The wire broke at the midle with single load 295 grms
The wire hold on overnight at single load 242 grms Vezo torque wrench is not accurate! This test was performed ~ 1.5Nm DO NOT USE THIS NUMBER! (added at 8-10-2016)
This gives us a factor of 2 safety with loop suspended of 250 grms small optic.
Gautam and Steve,
The clamp's left side was jammed onto the left guide pin. It was installed slit facing left. Gautam had to use force to remove it. The clamp should move freely seating on the guide rods till torque aplied. Do not move on with the hanging of optic with a jammed clamp. Fix it.
Never use force as you are hanging - aligning optic. The clamp is in the shop for resurfacing and slit opening.
ETMY UL epoxy soaking dish. All teflon in glass.
Guralps as connected with pictures
Ni plated SmCo magnets with specification of LIGO-C1103521-v2 for SOS ordered from Electron Energy Corp
100 pieces of Ni- Platted magnets are in 9-27-2016 They are stored at clean cabinet S15
EP30-2 epoxy 1/2 pt kit 250 ml of part A and 25 ml of part B should be here in 7 days. These can packed epoxy is much more economical than the double barrel cartridges.
Spare SOS wire clamps will be out of the machine shop next week.
0.0017" OD., 500ft steel music wire ordered. Pictures of the existing roll are below. It will be on 8" OD. spool too.
RGA background scan
Vacuum Status: Chamber Open
All chamber annuloses are vented. Vac Monitor screen is not communicating with gauges. The valve position indicator are working.
RGA is pumped by Maglev through VM2
New Wiha 28504 torque wrench for SOS wire clamping. It's range 7.5 - 20 in-lb in 0.5 steps [ 0.9 - 2.2 Nm ] Audible and perceptible click when the pre-set torque has been attained at ±6% accuracy.
The new ETMX sus wire torqued to ~ 11.5 in-lb [1.3 Nm ]
The saga has started here We have to give credit to the Boss who fixed it. The seismometers themself are not labeled yet.
Atm6 added on 8-12-2016 EX needed to be centered
Thanks to Max for the nice plost at summery pages
The 7.5 in-lb of Wiha seems at the upper end of torque range for a 4-40 SS screw
Wiha 28502 ordered with range 5 -10 in-lb for silver plated 4-40 screws
Do not trust the Venzo torque wrench under 2 Nm ! It miss lead me.
Recommended torque values for silver-plated fasteners are here. For aLIGO we use the guidelines in T1100066-v6, This doc is posted in 40m wiki under Mechanics also.
So, we'll use 6 in-lbs on silver plated 18-8 stainless steel socket head cap screw 4-40 x 3/8 into SS tower bridge.
Please replace these clamp screws every time if they were tightened without a torque wrench.
2.1 mag earth quake in Norhten Ca
Our seimometers need professorial centering. Related electronics must be checked too.
The wire will arrive in 1-2 weeks. It is a new production. Brad Snook of Ca Fine Wire was suprised that we are still using the 13 years old wire. Oxidation is an issue with iron contained steel wire.
He would not give me a shelf life time on it. He recommended to check the strenght of it before usage. It passed with safety factor of 2 just recently.
In the future we'll store the new spool in oxigen free nitrogen environment..
0.0017" OD., 500ft steel music wire ordered. Pictures of the existing roll are below. It will on 9" OD. spool too.
The SOS ETMY tower had and Aluminum bridge. How is it possible that this was true? Is SS better than Al for some quantitative scientifc reason ???
Their weight ratio as measured = 922 / 307 g = 3
Destinies: SS 304 / Al 6061 > 0.289 / 0.098 [ lb /in3 ] = 2.94
The wire inprints were removed by 800P grain paper [Norton 73568] The SS bridge block now has an undesireble vally in the wire location.
The sus bridges were soaked in acetone over night and sonicated to remove residual sand paper.
I just put in the following into the air bake oven for a 12 hour, 70C bake:
I put these in at 10.30pm. So the oven will be turned off at 10.30am tomorrow morning. The oven temperature seems stable in the region 70-80 C (there is no temperature control except for the in built oven control, I just adjusted the dial till I found the oven remains at ~70C.
Tomorrow, we will look to put on first contact onto the ETMs, and then get about to re-suspending them.
Stress Relieved 0.0017" Music Wire CFW P/N: CFW2035025, Made 08-17-2016
GBL (grams breaking load )
UTS (ultimate tensile strength)
YTS (yield tensile strength)
The IFO room temp is up a bit and it is coming down. The out side temp is not really high.
This problem has existed well before the vent
How to minimize particles entering the vacuum envelope.
Just the way it was in August 2011 vent and before.
The portable HEPAs were set up at ETMY and ITMY with CP STAT 100 curtains.
The 40m particles on the floor at ITMY 3000-5000 counts of 0.5 micron cf / min and 0.3 micron size particles are 55,000 - 65,000 counts cf / min
At this condition the MET One Counter #3 on the floor inside the tent goes to zero count of 0.5 micron and 20-40 counts cf / min for 0.3 micron when the tent is slightly overpressured.
100 Sapphire prisms ordered. Delivery date 9-30-2016
~60 deg. prisms,
Size A=B=C=2 mm, length 5 mm
Surface quality: 5 micron RMS
Tolerances: +- 0.1 mm
This prism will be used as a mechanical component
No crystal orientation required
There are some issues with 5 mm sapphire prism Atm5. It will cause interference between one of the prisms and the Side OSEM.
Here are some drawings to see the issues with larger wire standoff.
The 2 mm prism will work.with a 1 mm longer dumbell.
Quotes requested from http://photomachining.com/laser-micromachining-photomachining-contact.html and http://www.optocity.com/
So if the SRM satellite box is good, than the ITMY sensor UL or vacuum cabeling from sersor to sat amp is bad.
Koji tweaked the alignment sliders till we were able to get the Y arm locked to green in a 00 mode, GTRY ~ 0.5 which is the prevent number I have in my head. The green input pointing looks slightly off in yaw, as the spot on the ITM looks a little misaligned - I will fix this tomorrow. But it is encouraging that we can lock to the green, suggests we are not crazily off in alignment.
[Ed by KA: slider values: ETMY (P, Y) = (-3.5459, 0.7050), ITMY (P, Y) = (0.3013, -0.2127)]
While we were locked to the green, ITMY UL coil acted up quite a bit - with a large number of clearly visible excursions. Since the damping was on, this translated to somewhat violent jerking of ITMY (though the green impressively remained locked). We need to fix this. In the interest of diagnosis, I have switched in the SRM satellite box for the ITM one, for overnight observation. It would be good to narrow this down to the electronics. Since SRM is EQ-stopped, I did not plug in any satellite box for SRM. The problem is a difficult one to diagnose, as we can't be sure if the problem is with the LED current driver stage or the PD amplifier stage (or for that matter, the LED/PD themselves), and because the glitches are so intermittent. I will see if any further information can be gleaned in this regard before embarking on some extreme measure like switching out all the 1125 OpAmps or something...
Does anyone know if we have a spare satellite box handy?
Is the spare sat amp is bad ?
This is an option to isolate the vacuum chamber from the dusty 40m lab: 4x8 HEPA unit or Air Curtain
It does not limit crane operations. Here is some science based approach to air filters
Lets put horizontal and vertical witness plates next to our arm cavity TMs just before pumpdown.
Visiting graduate student Teng Zhang from Glasglow received 40m specific safety training yesterday.
We are pumping down. The annuloses are below 10 mTorr
The vacuum gauges are not communicating with the medm so there is no plot available.
The main volume pumping is stopped at P1 = 220 Torr ( New SuperBee 174 Torr ) for overnight.
note: SuperBee was reading 791 Torr at atm and it was not set to 760 !
P1 IFO pressure is 1 mTorr, valve configuration: vacuum normal, annulosses are pumped, RGA is off, not pumped.
THANKS to Chris !
The shutters can be opened with high power.
No communication error message still exist.
I will reboot c1vac1 and c1vac2 to get gauge communication with medm tomorrow.
The pumpdown had stalled because of some ancient vacuum interlock code that prevented opening the valve V1 between the turbo pump and the main volume.
This interlock  compares the channels C1:Vac-P1_pressure and C1:Vac-PTP1_pressure, neither of which is functioning at the moment. The P1 channel apparently stopped reading sometime during the vent, and contained a value of ~700 torr, while the PTP1 channel contained 0. So the interlock code saw this huge apparent pressure difference and refused to move the valve.
To bypass this check, we used caput to enter a pressure of 0 for P1.
I believe that the UR and LR magnets are stuck. There was no earth quake at 16:18 yesterday. Something had to kick it into this position. See 4days plot
Please advise freeing details.
Something strange happened to the ITMX osem reading around 4.pm. PDT as shown below.
Also the there was no response of the reading as we adjusted the PITCH and YAW. :(
Note that we restarted the slow machine: c1susaux,c1ausex this afternoon because of the unresponced interface.
The pumpdown started at 9-12-2016
The IFO is at 5e-5 Torr vacuum normal after 73 day at atm.
ITMX needed to be freed and ETMY-UL is still misbehaving occasionally.
New pirani and cold cathode gauges added at this vent. They were baked at 100 C for 6 hrs under vacuum.
Go to the Vac Rack to read IFO pressure from the gauge itself when Vac. Monitor is blank as it is now !
P1 IFO pressure is 1 mTorr, valve configuration: vacuum normal, annulosses are pumped, RGA is not pumped.
IFO pressure 3.7e-5 Torr at new cold cathode InstruTech - Hornet
New items in vacuum:
1, ETMX sus tower with new baked sus wire, EP30-2 epoxied magnets, same at different locations also........ .......... and 2 ruby wirestandoffs.
2, First Contact cleaned arm test masses only. This technic was a 1st time use in our vacuum system.
3, 50 mm ID green glass baffles at the ends
4, witness mirrors at ETMX and ITMY (old oplev mirrors) We observed a very dusty system: sides of optics, towers and tables were wiped. Hepa tents used at Y arm and BS
5, new pirani, cc gauge and 1.5" right angle valve
REF33 was removed for taking picture of the bare C30362 InGaAs photodiode per Rana's request. All other rf photodiodes have their glass cover on.
Note: it is back to it's place but this pd will need alignment!
The small steering mirror was completly lose before it was removed.
Good 8 hours
The misalignment wasn't as bad as I had intially feared; the spot was indeed pretty high on ETMX at first. Both transmon QPDs did need a reasonable amount of steering to center once the dither had centered the beam spots on the optics.
Arms, PRMI and DRMI have all been locked and dither aligned. All oplevs and transmon QPDs have been centered. All AS and REFL photodiodes have been centered.
Green TM00 modes are seen in each arm; I'll do ALS recovery tomorrow.
The earth quake shook ITMX free for a short while.
[ Gautam and Steve ]
c1vac1 and c1vac2 were rebooted and the gauges are communicating now. V1, VA6, V5 and V4 were closed and disconnected to avoid unexpected valve switching. All went smoothly.
The new ITcc gauge is at 1e-5 Torr as CC1 This is the gauge that should be logged in slow channel.
TP2 fore line dry pump was replaced this morning after 382 day of operation.
TP3 dry pump is very noisy, but it's pressure still 47 mTorr
[ericq, Gautam, Steve]
Following roughly the same procedure as ELOG 11354, c1vac1 and c1vac2 were rebooted. The symptoms were identical to the situation in that ELOG; c1vac1 could be pinged and telneted to, but c1vac2 was totally unresponsive.
The only change in the linked procedure was that we did not shut down the maglev. Since I unwittingly had it running for days without V4 open while Steve was away, we now know that it can handle shorter periods of time than that...
Upon reboot, many channels were readable again, unfortunately the channels for TP2 and TP3 are still blank. We were able to return to "Vacuum normal state," but because of unknowned communication problems with VM1's interlock, we can't open VM1 for the RGA. Instead we opened VM2 to expose the RGA to the main IFO volumn, but this isn't part of the "Normal" state definite, so things currently read "Undefined state".
The last good rga scan at vent 78 day 38
The RGA is removed for repaire. It's volume at atmophere and sealed.. P4 reading of 38 Torr is not correct.
The IFO room temp is up
Local earth quake 3.7 mag trips PRM
What about the MC?
It started here
100 Sapphire prizms arrived.
I have completed the following non-Steve portions of the pre-vent checklist [wiki-40m.ligo.caltech.edu]
All shutters are closed. Ready for Steve to check nuts and begin venting!
- checked all jam nuts
- checked all viewports are covered
- turned oplev servos off
- took pictures of medm screens: sus summs, aligned oplev centering, IFO& MC alignment biases and vac configuration
- checked particle counts
- checked crane operational safety
- closed V1, VM1, annuloses
- opened VV1 and vented with Airgas brand, Industrial Grade Nitrogen [ 99.99% ] to 25 Torr
- switched over to Airgas brand compressed air, Alphagas " AI UZ300 " with Total Hydro Carbon 0.1 PPM
IFO is at atmosphere. The MC can be locked in air now.
The doors will be coming off tomorrow 8am sharp.
Do we want to install the ITM baffles?
What about the found OSEM filters?
Ashley Fowler "high shool" student received basic 40m safety training and Lydia is her guarding angle.
Everybody is happy, except ITMY_UL or satalite box.
Gautam shows perfect form in the OMC chamber.
Tilted viewports installed in horizontal position. Atm2
Pumping again after 7 days at atmosphere.
BS, ITMY and OMC chambers were open only.
Checked: jam nuts, viewport covers and beam shutters.
Oplev servo turned off and medm screens shots taken.
New item in vacuum: green shade 14 glass beam block at IR-input [ from the PSL ] viewport to block green reflection-scatter.
Reminder: viewport is not AR coated for green!
IFO pressure 1.7E-4 Torr on new not logged cold cathode gauge. P1 <7E-4 Torr
Valve configuration: vac.normal with anunulossess closed off.
TP3 was turned off with a failing drypump. It will be replaced tomorrow.
Dry pump of TP3 replaced after 9.5 months of operation.[ 45 mTorr d3 ]
The annulosses are pumped.
Valve configuration: vac normal, IFO pressure 4.5E-5 Torr [1.6E-5 Torr d3 ] on new ITcc gauge, RGA is not installed yet.
Note how fast the pressure is dropping when the vent is short.
All time stamps are blank on the MEDM screens.
We may have a mouse in the lab. Do not leave any food scrap in trash ! Traps will be set.