There is BLANK VacControl_BAK.adl screen only. 

I can move a valve by disconnecting it's  solenoid power if it's position is normally open.

I will close V1 and check computer cable connections and move on with manual - hand disconnect ea valve to be moved into the right position for vent. Valve positions will be confirmed by looking manual indicators on valves.

Rana stated yesterday that there will be a vacuum control update in the close future. Witnesses : Rich, Chris and Dave

Can you give me this in writing?

Convectron gauge check:

Brand new 10 years old convectron gauge at atm was swapped into the place of existing gauges to see if they read close to 760 Torrs

They did reasonable well at the low end. I tried to imitate calibration and bring down the high end with little success.

( P1 and P2  were reading 7e-4 to ~660 Torr  The correction of the upper end pushed up the lower end too. I will correct this later

P3 and P4 high ends are way off )

The point is that they work.  Convectron gauges will be replaced and calibrated at the next vent.

Interlocks were not triggered during this test. I was expected to close the PSL shutter when P1 was reading 760 Torr

This hide some problem or  not understanding.

It was good to see CC1 and CC4 working at the moment

Somehow I succeded opening VM1 and closed VM2 = vacuum normal

I just hope it stays open overnight to get comparable RGA scan.

In Steve's absence, I've tried to keep an eye on the health of the vacuum system. From Attachment #1, the pressure of the main volume seems stable, no red flags there. I also don't here any anomalously loud sounds near the vacuum pumps. I've changed the N2 cylinders that keep V1 open twice, on Wednesday and Sunday of last week. So in summary, the vacuum system looks fine based on all the metrics I know of.

(Steve, Chris)

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 [0] 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.

[0] /cvs/cds/caltech/state/from_luna/VacInterlock.st

Morning condition: vacuum rack power is still off, no MEDM screen reading.....meaning unknown vacuum pressure.We closed PSL shutter immediately.

Joe restored c1iscepis and Jenne powered up the vac-rack UPS. Now the rest of the vac-rack power were restored from starting at the top to bottom.

P1 was reading 15 mTorr.  We restarted pumps and  set vacuum valve positions. V1 opening required Rob's recipe of elog # 1863 to defeat interlock that

has a non communicating gauge: PTP1

CC1 pressure just reached 1e-6 Torr at VAC NORMAL configuration.

State condition: Vac Normal,          CC1 ~8e-6 Torr

The IFO pressure peaked at  8.3 mTorr after 2days of not pumping.

CLOSE CALL on the vacuum system:

Jamie and I disabled V1, VM2 and VM3 gate valves by disconnecting their 120V solenoid actuator before the swap of the VME crate.

The vacuum controller unexpectedly lost control over the swap as Jamie described it. We were lucky not to do any damage! The ion pumps were cold and clean. We have not used them for years so their outgassing possibly  accumulated to reach ~10-50 Torr

I disconnected_ immobilized and labelled the following 6 valves:  the 4 large ion pump gate valves and VC1,  VC2  of the cryo pump. Note: the valves on the cryo pump stayed closed. It is crucial that a warm cry pump is kept closed!

This will not allow the same thing to happen again and protect the IFO from warm cryo contamination.

The down side of this that the computer can not identify vacuum states any longer.

This vacuum system badly needs an upgrade. I will make a list.

 ITMX damping restored.

 Out gassing plus leak rate   0.15  mTorr / hour

 The pressure rose to 2.5 mTorr in 17 hours

 V1 was opened at 1:56pm

 VM2 opened at 2:10 so the RGA region is back to 1e-5 torr

 Valve configuration:       Vacuum Normal    is reached in really 4 days if we do not count overnight rest of roughing.

 VA6 and VC2 are reconnected. I'm turning on the RGA next

 All 4 ion pumps were vented with air and pumped down to ~ 1e-4 Torr

 Ion pumps gate valve control cables are connected and their pumps are disconnected.

 The black relay box was tested repeatedly and it stopped misbehaiving.

We were at atmosphere for 13 days.  Chamber BS, ITMX, ITMY and ETMY were opened.

Al foil "cups" were placed on the back side OSEMs of PRM.

RP1 and RP3 roughing pump manual of Leybold D30A oily rotory pump

Fore pump of TP2 & TP3 Varian SH-100 Dry Scroll

TP2 and TP3 small turbo drag pump  Varian 969-9361 

TP2 and TP3 turbo controller Varian 969-9505

TP1 magnetically suspended turbo pump  Osaka TG390MCAB, sn360 and controller TC010M  and note : this  pump  running on 208VAC single phaseIt is not on the UPS !  

                                                             Osaka Maglev Manual        and Osaka Controller Communication Wiring                                                                                                                                

VC1 cryo pump CTI-Cryogenics Cryo Torr 8 sn 8g23925  SAFETY note: compressor single phase 208VAC and the head driver 3 phase 208VAC Compressor and driver have each separate power cord!

Installed at 40m wiki  also

 While I was doing the oil change of the roughing pumps I accidentally touched the 24 V adjustment knob on the power supply.

All valve closed to default condition. I realized that the current indicator was red at 0.2A  and the voltage fluctuated from 3-13V

Increased current limiter to 0.4A and set voltage to 24V     I think this was the reason for the caos of valve switching during the VME swap.

We did the following:

1, closed V1, VM1,  annuloses: VASE, VASV, VABS, VAEV,  VAEE and VA6

2, stop rotation of Maglev-TP1, waited to decellerate and turned off power to it

3, closed V4,  stoped rotation of TP2, waited to decellerate and turned power off

4, opened VM3 to RGA that is still running

I will come in tomorrow 9-10am to restart pumping.

The V1 gate valve specs installed at 40m wiki page. VAT model number 10846-UE44-0007 Our main volume pumping goes through this 8" id gate valve V1 to Maglev turbo  or Cryo pump to  VC1

The ion pumps have 6" id gate valves:VAT 10844-UE44-AAY1,  Pneumatic actuator with position indicator and double acting solenoid valve 115V 60Hz  Purchased 1999 Dec 22

UHV gate valves 2.5" id. VAT  10836-UE44    Pneumatic actuator with position indicator and double acting solenoid valve 115V 60 hz, IFO to RGA  VM1 &  RGA to Maglev  VM2

mini UHV gate valve 1.5" id.   VAT  01032-UE01      2016 cataloge page 14,   manual - no position indicator, VM4  next to manual adjustable fine leak valve to RGA

UHV angle valve 1.5" id, model VAT 28432-GE41, Viton plate seal, pneumatic actuator with position indicator & solenoid valve 115V & single acting closing spring  MEDM screen: VM3,VC2, V3,V4,V5,V6,VA6,V7 & annuloses Each chamber annulos has 2 valves.

UHV angle valve 1.5" id, model VAT 57132-GE05   go page 208,   Metal tip seal, manual actuating only with position indicator,   MEDM screen: roughing RV1 and venting VV1 hand wheel needed to close to torque spec

UHV angle valve  1.5" id. model VAT 28432-GE01           Viton plate seal, manual operation only at IT gauges Hornet & Super Bee and  ion pumps roughing  ports. These are not labeled.

The Cryo pump interlock wiring was added too

Note: all moving valve plate seals are single.

This condition is created when we run out of nitrogen that holds the valves in set positions. The Maglev and other turbos are still running in this configuration so one has to pay attention that the foreline valves are open.

Reset  error message on vacuum screen and opened V4 & V5 at 3pm today.

We started a vacuum work in this morning. And still it's going on.

Although the last night the green team replaced a steering mirror by an 80% reflector on the PLS table, the beam axis to the MC looks fine.

The MC refl beam successfully goes into the MCrefl PD, and we can see the MC flashing as usual.

We started measuring the distance of the optics inside the vacuum chamber, found the distance from MC3 to MMT1(curved mirror) is ~13cm shorter than the design.

We moved the positions of the flat mirror after the Faraday and the MMT1, but could not track the beam very well because we did not completely lock the MC.

Now we are trying to get the lock of the MC by steering the MC mirrors.

P.S.

Kevin suceeded in locking it !!

 Hey guys,

I just finished redoing the calc based on the measurements that happened last week.  Using the average of the Vert and Horz measurements in Kevin's elog 2986, I find that we need to make the MMT telescope ~8cm longer.  So, can you please place the flat mirror after the Faraday in the same place as the drawing, but move the MMT1 79mm farther away from that flat mirror?  Looking at the table layouts that Koji has on the wiki, this should still (barely) fit.

New distances:

d2a = 884.0mm (no change) ------  MC3 to Flat after Faraday

d2b = 1123.2mm (move MMT1 farther toward center of BS table)  -------- Flat after Faraday (SM1) to MMT1

d3 = 1955.0mm (result of moving MMT1)  ---------  MMT1 to MMT2

d4a = 1007.9mm (no chnage)        ----------- MMT2 to SM2

d4b = 495.6mm (no change) ------------ SM2 to PRM

I just got off the phone with Alberto and Kiwamu, and I'm going to try to recalculate things based on their measurements of the distances between MC3 and SM1.  It sounds like the CAD drawings we have aren't totally correct.    I know that when we opened doors just before Christmas we measured the distances between the BS table and the ITM tables, but I don't think we measured the distance between the IOO table and the BS table.  Hopefully we can fit everything in our chambers.....

As preparation for the upcoming planned power outage we turned turbos, RGA off and closed valves.

IFO chamber is not pumped now. Small leaks and out gassing will push the pressure up slowly. At 3 mTorr of P1 the PSL output shutter

will be closed by the interlock.

It is OK to use light in the IFO up to this point.

The vacuum system is coming up to atm. The vent was started with slow N2 flow. The PSL output is blocked 2 places on the table.

 IFO_P1 pressure 1.6e-5 torr after 6 days at atm

PS: PSL sliding door 11 was left open overnight. The PSL particle count will reach room counts in 20 seconds at low speed of HEPA

  VENT OBJECTIVES:

1, Fix ETMX sus "jump issue"

2, First Contact clean the arms

3, Install new spare cold cathode and convectron gauges: InstruTech-Hornet

4, Install 50 mm apeture beam baffles

5, Check and clean optical quality viewport from inside

The following bullets were executed:

• Closed shutter of PSL-IR and green shutters at the ends 
• Checked jam nuts are protecting bellows 

• Check crane functionality & cleanliness last week

• Particle count must be under 10,000 counts / cf min for 0.5 micron 
• Checked all metal window covers are on. 
• Check 5 cylinders (24 cft size) of instrument grade air, called Alfa Gas 1 in stock.
• Took pictures of medm screens: sus-sum, aligned oplevs pos, alignment values and vac configuration
• Turned Oplev servos off
• Closed V1 and VM1, opened VM2
• Opened VV1 manual valve to Nitrogen cylinder and let the P1 to rise to 25 Torr
• Switched over to Instrument Grade Air Cylinder and continoed the vent with 8-10 PSI reading at the pressure regulator

We are venting the 40m IFO

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

I just disconnected the 6th instrument grade air cylinder from the vacuum envelope at 720 Torr. Now it will reach equilibrium through a filter as it sucks in lab air.

This is the sure way not to over pressurize the chamber.

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?

- 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

 ITMY in vac table needs leveling.

 The access connector was removed, BS and ITMY chambers were opened yesterday.

New one piece aluminum shell access connector installed. Jenne lowered the PSL out put into MC to ~100mW

The vent has been finished.

Now the pressure inside the chamber is 760 torr, and it's getting equilibrium with the atmospheric pressure.

Therefore we are ready and can open the door of the chamber tomorrow.

The vent has been finished successfully in this morning.

_{The vent was finished successfully this morning.}

 Thanks to Kiwamu, Alberto and Koji

Koji, Jamie and I talked together and I decided to VENT TOMORROW MORNING. Main purpose of this vent is to see if PRM is flipped or not.

Vent schedule:
June 28 (Thu)
  Prepare for the vent tonight

June 29 (Fri)
  Start vent in the morning
  Look into PRC in the evening. If PRM was flipped, we will correct them. We'll use REFL to align the PRM. If PRM was not flipped, look into PR2,PR3 and other related optics.

June 30 (Sat)
July 1 (Sun)
  Thinking time. I can work if needed.

July 2 (Mon)
  If we need something else to do, do it.
  If not, start pumping.
  July 4th is the Independence Day. So, I need IFO working before July 4th.

Check List:
 We will just open the BS chamber.
  - PRM flipping
  - PR2, PR3 flipping
  - PRC suspensions
  - Cipping check in PRC

 What do you mean by PR2, PR3 flipping?  They are (supposed to be) flat mirrors, so obviously they should be installed correctly, but they won't change the mode matching in a huge way if they're backwards, right?

For the PRM, I recommend checking (a) the arrow inscribed on the thinner side of the optic and (b) that the arrow *actually* points to the HR side.  I'm pretty sure I installed all the optics with the arrow pointing away from the OSEMs, but I never did a thorough check that the arrow always actually pointed to the HR coated side.  I don't remember any optics where I said "hmmm, that's funny, the arrow is pointing backwards", but nor did I write down that I had checked.

Also, hopefully the PRM is correct.  If however it's not, that means that all of the magnets are glued onto the HR side, and we'll have to redo all of the magnet gluing.  The guiderods should be fine, but all 6 magnets would need redoing.  If we were very, very careful and didn't break any of the magnets off of the dumbbells, it's a 24 hour turnaround due to drying time.  Since inevitably we break magnets away from dumbbells, conservatively we should think about a 48 hour turnaround. 

We see some ghost beam spots at POP. This may come from the back of PR2 and PR3. Also, they may change mode matching because of thermal lensing, mirror deformation, and other unexpected reasons. I thought we should check every mirrors in PRC, if PRM is not flipped.

We are going to check PRM just because we spent so much time for the PRC problem, and still don't have the solution or evidence.
PRM flipping is kind of the only idea for the root of all evil -- terrible beam shape, low PR gain, unstable PRMI lock.
So, I want to check with my eye during the stay.

I don't think we have to redo magnet gluing. It's okay to leave them on HR side.

 The 40m vacuum envelope is at atm    It took 4.5 hours at ~3 Torr/min speed. Atm1

What I did:

Turned PZT voltages off: 84.1V at OMC-rack location

                                           -  99V at 1Y3 location as PZT_pitch,

                                             56.6V KEPCO at 1Y3 location as PZT_yaw                                           

Took screen shuts of SUS_SUMMARY, yesterday,  Atm3

Turned off OPLEV _SERVOs, today , Atm2

Closed PSL_SHUTTER and green shutters at the ends

Set vacuum valves for vent position and opened VM2 for the RGA

 PSL shutter closed, manual block in place, HV turned off. P1 is at 200 Torr now.  Jenne is taking over here.

 Valves closed, 500 torr.  Steve will finish off Monday morning, then we'll take off doors and get to work.

P1 at 750 Torr,  Vent valve VV1 is left open to atm. It will reach equilibrium in an hour. The PSL power is not turned down yet. The beam path is blocked at two places inside the enclosure.

The low power 20 mW  input  MC can be locked tonight.

Next day's - Thursday notes:

We  reached 760 Torr of atm in 8 hrs at  1.7 Torr/ min with 5 cylinders of  instrument grade air.

Used 500 PSI of nitrogen to get to 20 Torr at first.  This flow  and the first cylinder of N2  has to be slower next time.

We did the following:

1, oplevs were centered on locked caveties 2 days ago

2, just before vent we rechecked arms  pointing, they wre still locking

3,eloged strain gages  and turned HVs off at PZT-steering   at 1Y3 rack and OMC-PZT ps at 1X2 aux rack. They were actually off.

4,,checked jam nuts 6 places x 3

5, turned oplev servos off

6, eloged SUS summery page

7, checked particle counts at ITMY: 1 micron 300,  0.5 micron 3K,  0.3 micron  30K particles / cft-min. All three cranes were wiped 2 days ago.

8, blocked laser into IFO: main 1064 in 1.25W were blocked by manual 2 blocks on PSL table. The PSL output shutter was left open to be triggered by interlock  at P1 3 mTorr. It did!

    Aux NPRO-AP and green light  input at both ends were blocked.

 Kiwamu has completed the vent.

 The vent is completed. ITMX was kicked up accidentally. Valve configuration: chamber open, RGA is pumped through VM2  Maglev

[Steve, EricQ, Jenne]

ITMY and BS heavy doors are off, light doors are on.  Q is aligning the IFO.

Status update on dichroic mirror:

 I got the specification sheet of an aLIGO 2" dichroic mirror from Lisa.

https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=25232

This is the one from ATF. It has low loss, a high R for 1064 nm and high T for 532 nm. So it matches our needs.

Based on this sheet we may reset some of the parameters in the specification (e.g. incident angle and etc.,) and will get a quote from ATF.

We will buy 3 of them, including 1 spare. First I need to review the specification.

We are discussing venting first thing next week, with the goal of
diagnosing what's going on in the PRC.

Reminder of the overall vent plan:

https://wiki-40m.ligo.caltech.edu/vent

Since we won't be prepared for tip-tilt installation (item 2), we should
focus most of the effort on diagnosing what's going on in the PRC.  Of
the other planned activities:

(1) dichroic mirror replacement for PR3 and SR3

  Given that we'll be working on the PRC, we might consider going ahead
  with this replacement, especially if the folding mirror becomes
  suspect for whatever reason.  In any case we should have the new
  mirrors ready to install, which means we should get the phase map
  measurements asap.

(3) black glass beam dumps:

  Install as time and manpower permits.  We need to make sure all needed
  components are baked and ready to install.

(4) OSEM mount screws:

  Delay until next vent.

(5) new periscope plate:

  Delay until next vent.

(6) cavity scattering measurement setup

  Delay until next vent.

 Bob is back. Cleaning and baking all our posts and clamps. They will be ready for use Tuesday next week. Therefore beam dumps will be available for installation.