40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 85 of 341  Not logged in ELOG logo
ID Date Authorup Type Category Subject
  15459   Wed Jul 8 08:51:35 2020 JordanUpdateGeneralPresence at 40m

I will be in the clean and bake lab today from 9am to 3pm.

  15461   Thu Jul 9 09:22:44 2020 JordanUpdateGeneralPresence at 40m

I will be in the Clean and Bake lab today from 9am to 3pm

  15467   Fri Jul 10 10:37:30 2020 JordanUpdateGeneralPresence at 40m

I will be in the Clean and Bake lab today from 9am to 4pm

  15478   Tue Jul 14 09:04:53 2020 JordanUpdateGeneralPresence at 40m

I will be in the Clean and Bake Lab today from 9am to 4pm.

  15492   Fri Jul 17 09:03:58 2020 JordanUpdateGeneralPresence at 40m

I will be in the Clean and Bake lab today from 9am to 4pm.

  15500   Fri Jul 24 15:40:59 2020 JordanUpdateVACInstallation of two new UPS units

I installed the Tripp Lite SMX1000RT2U and Tripp Lite Smart1000LCD at the bottom of the 1x8 electronics rack. These are plugged in to power, and are ready for testing. All other cables (serial, usb, etc.) have been left on the table next to the 1x8 rack.

Attachment 1: UPS.jpg
UPS.jpg
  15591   Mon Sep 21 15:57:08 2020 JordanUpdateVACTP3 Forepump Replacement and Vac reset

I removed the forepump (Varian SH-110) for TP3 today to see why it had failed over the weekend. I tested it in the C&B lab and the ultimate pressure was only ~40torr. I checked the tip seals and they were destroyed. The scroll housing also easily pulled off of the motor drive shaft, which is indicative of bad bearings. The excess travel in the bearings likely led to significant increase in tip seal wear. This pump will need to be scrapped, or rebuilt.

I tested the spare Varian SH-110 pump located at the X-end and the ultimate pressure was ~98 mtorr. This pump had tip seals replaced on 11/5/18, and is currently at 55163 operating hours. It has been installed as the TP3 forepump.

Once installed, restarting the pump line occured as follows: V5 Closed, VA6 closed, VASE Closed, VASV closed, VABSSCI closed, VABS closed, VABSSCO closed, VAEV closed, VAEE closed,TP3 was restarted and once at normal operation, valves were opened in same order.

The pressure differential interlock condition for V5 was temporaily changed to 10 torr (by Gautam), so that valves could be opened in a controlled manner. Once, the vacuum system was back to normal state the V5 interlock condition was set back to the nominal 1 torr. Vacuum system is now running normally.

Attachment 1: Screenshot_from_2020-09-21_15-56-04.png
Screenshot_from_2020-09-21_15-56-04.png
Attachment 2: 20200921_145043.jpg
20200921_145043.jpg
Attachment 3: 20200921_145040.jpg
20200921_145040.jpg
  15602   Wed Sep 23 15:06:54 2020 JordanUpdateVACTP2 Forepump Re-install

I removed the forepump to TP2 this morning after the vacuum failure, and tested in the C&B lab. I pumped down on a small volume 10 times, with no issue. The ultimate pressure was ~30 mtorr.

I re-installed the forepump in the afternoon, and restarted TP2, leaving V4 closed. This will run overnight to test, while TP3 backs TP1.

In order to open V1, with TP3 backing TP1, the interlock system had to be reset since it is expecting TP2 as a backing pump. TP2 is running normally, and pumping of the main volume has resumed.


gautam 2030:

  1. The monitor (LCD display) at the vacuum rack doesn't work - this has been the case since Monday at least. I usually use my laptop to ssh in so I didn't notice it so it could have been busted from before. But for anyone wishing to use the workstation arrangement at 1X8, this is not great. Today, we borrowed the vertex laptop to ssh in, the vertex laptop has since been returned to its nominal location.
  2. The modification to the interlock condition was made by simply commenting out the line requiring V4 to be open for V1 to be opened. I made a copy of the original .yaml file which we can revert to once we go back to the normal config.
  3. I also opened VM1 to allow the RGA scans to continue to be meaningful.
  4. At the time of writing, all systems seem nominal. See Attachment #2. The vertical line indicates when we started pumping on the main volume again earlier today, with TP3 backing TP1.

Unclear why the TP2 foreline pump failed in the first place, it has been running fine for several hours now (although TP2 has no load, since V4 isolates it from the main volume). Koji's plots show that the TP2 foreline pressure did not recover even after the interlock tripped and V4 was closed (i.e. the same conditions as TP2 sees right now).

Attachment 1: Screenshot_from_2020-09-23_15-15-43.png
Screenshot_from_2020-09-23_15-15-43.png
Attachment 2: MainVolPumpDown.png
MainVolPumpDown.png
  15615   Tue Oct 6 14:35:16 2020 JordanUpdateVACSpare forepumps

I have placed 3 new in box, IDP 7 forepumps along the x arm of the interferometer. These are to be used as spares for both the 40m and Clean and Bake.

  15806   Fri Feb 12 15:03:48 2021 JordanUpdateSUSCoM on 3"->2" Adapter Ring for SOS

As it currently stands the Center of Mass of the Adapter Ring/Optic assembly is 0.0175" out of the plane formed by the suspension wire. See Attachments. The side plate, along with the EQ stops are hidden to show the CoM and the plane.

Note: The changes discussed in the meeting with Calum have not been added and are a work in progress. These changes include:

- Adding a 45 deg chamfer to the both parallel faces of the adapter ring. This along with a modified bracket for the EQ stops will allow for easier adjustment of the screws. 

- Potentially changing material of adapter ring to stainless stell to more accurately emulate the mass of a 3" optic.

- Different adjustment mechanism of the "dumbell" at bottom of adapter ring to something similar to the VOPO suspension (will need to consult Calum further)

Attachment 1: Screenshot_(1).png
Screenshot_(1).png
Attachment 2: Screenshot_(3).png
Screenshot_(3).png
Attachment 3: CoM.PNG
CoM.PNG
  15823   Fri Feb 19 15:17:51 2021 JordanUpdateSUSCoM Range on 3"->2" Adapter Ring for SOS

Adjusting the thickness of the cylindrical hole for the mirror on the 2" optic sleeve, from .6875" to .61" thick, moves the CoM to 0.0003" out of plane from the suspension wire. This is with the dumbell at its neutral point.

How close to zero do we need this to be? More fine tuning of that thickness can get it to zero, but this would require much tighter machining tolerance on that hole depth.

Moving the dumbell towards the back of the SOS assembly (noted as negative direction, with origin at the plane formed by the wires), moves the CoM to -0.002" from the plane.

Moving the dumbell towards the front of the SoS assmebly (positive direction wrt the plane formed by the suspension wire), moves the CoM to +0.0022" from the plane.

So the total adjustment range with the dumbell is -0.002"to 0.0022", with the plane formed by the wires as the origin.

See Attachments

Attachment 1: Neutral_Point.png
Neutral_Point.png
Attachment 2: Dumbell_Max_Negative_Travel.png
Dumbell_Max_Negative_Travel.png
Attachment 3: Dumbell_Max_Positive_Travel.png
Dumbell_Max_Positive_Travel.png
  15929   Wed Mar 17 10:52:48 2021 JordanUpdateSUS3" Ring Adpater for SOS

I have added a .1", 45deg chamfer to the bottom of the adapter ring. This was added for a new placement of the eq stops, since the barrel screws are hard to access/adjust.

This also required a modification to the eq stop bracket, D960008-v2, with 1/4-20 screws angled at 45 deg to line up with the chamfer.

The issue I am running into is there needs to be a screw on the backside of the ring as well, otherwise the ring would fall backwards into the OSEMs in the event of an earthquake. The only two points of contact are these front two angled screws, a third is needed on the opposite side of the CoM for stability. This would require another bracket mounted at the back of the SOS tower, but there is very little open real estate because of the OSEMs.

 

Instead of this whole chamfer route, is it possible/easier to just swap the screws for the barrel eq stops? Instead of a socket head cap screw, a SS thumb screw such as this, will provide more torque when turning, and remove the need to use a hex wrench to turn.

 

Attachment 1: Side_View.png
Side_View.png
Attachment 2: Front_View.png
Front_View.png
Attachment 3: Ring_with_Modifed_Bracket.png
Ring_with_Modifed_Bracket.png
Attachment 4: Back_of_ring.png
Back_of_ring.png
Attachment 5: Front_of_Ring.png
Front_of_Ring.png
  16004   Wed Apr 7 13:07:03 2021 JordanUpdateSUSCoM on 3"->2" Adapter Ring for SOS

Adding the chamfer around the edge of the optic ring did not change the center of mass relative to the plane from the suspension wires.

The CoM was .0003" away from the plane. Adding the chamfer moved it closer by .0001". See the attached photo.

I've also attached the list of the Moments of Inertia of the SOS Assembly.

Attachment 1: CoM_with_Chamfer.png
CoM_with_Chamfer.png
Attachment 2: Moments_of_Inertia.PNG
Moments_of_Inertia.PNG
  16047   Mon Apr 19 09:17:51 2021 JordanUpdateVACEmpty N2 Tanks

When I came into the lab this morning, I noticed that both N2 tanks were empty. I had swapped one on Friday (4-16-21) before I left the lab. Looking at the logs, the right tank (T2) sprung a leak shortly shortly after install. I leak checked the tank coupling after install but did not see a leak. There could a leak further down the line, possibly at the pressure transducer.

The left tank (T1) emptied normally over the weekend, and I quickly swapped the left tank for a full one, and is curently at ~2700 psi. It was my understanding that if both tanks emptied, V1 would close automatically and a mailer would be sent out to the 40m group. I did not receive an email over the weekend, and I checked the Vac status just now and V1 was still open.

I will keep an eye on the tank pressure throughout the day, and will try to leak check the T2 line this afternoon, but someone should check the vacuum interlocks and verify.

 

Attachment 1: N2_Pressure.PNG
N2_Pressure.PNG
  16064   Wed Apr 21 12:56:00 2021 JordanUpdateVACEmpty N2 Tanks

Installed T2 today, and leaked checked the entire line. No issues found. It could have been a bad valve on the tank itself. Monitored T2 pressure for ~2 hours to see if there was any change. All seems ok.

Quote:

When I came into the lab this morning, I noticed that both N2 tanks were empty. I had swapped one on Friday (4-16-21) before I left the lab. Looking at the logs, the right tank (T2) sprung a leak shortly shortly after install. I leak checked the tank coupling after install but did not see a leak. There could a leak further down the line, possibly at the pressure transducer.

The left tank (T1) emptied normally over the weekend, and I quickly swapped the left tank for a full one, and is curently at ~2700 psi. It was my understanding that if both tanks emptied, V1 would close automatically and a mailer would be sent out to the 40m group. I did not receive an email over the weekend, and I checked the Vac status just now and V1 was still open.

I will keep an eye on the tank pressure throughout the day, and will try to leak check the T2 line this afternoon, but someone should check the vacuum interlocks and verify.

 

 

Attachment 1: Screenshot_2021-04-21_12-53-26.png
Screenshot_2021-04-21_12-53-26.png
  16135   Wed May 12 14:23:20 2021 JordanUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units
Attachment 1: Moments_of_Inertia_SI.PNG
Moments_of_Inertia_SI.PNG
  16137   Wed May 12 17:06:52 2021 JordanUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units

Here are the mass properties for the only the test mass assembly (optic, 3" ring, and wire block). (Updated with g*mm^2)

Quote:

No, this is the property of the suspension assembly. The mass says 10kg

Could you do the same for the testmass assembly (only the suspended part)? The units are good, but I expect that the values will be small. I want to keep at least three significant digits.

 

Attachment 1: Moments_of_Inertia_SI.PNG
Moments_of_Inertia_SI.PNG
  16165   Thu May 27 14:11:15 2021 JordanUpdateSUSCoM to Clamping Point Measurement for 3" Adapter Ring

The current vertical distance between the CoM and the wire clamping point on the 3" Ring assembly is 0.33mm. That is the CoM is .33 mm below the clamping point of the wire. I took the clamping point to be the top edge of the wire clamp piece. see the below attachments.

I am now modifying the dumbell mechanism at the bottom of the ring to move the CoM to the target distance of 1.1mm.

Attachment 1: CoM_to_Clamp.PNG
CoM_to_Clamp.PNG
Attachment 2: CoM_to_Clamp_2.PNG
CoM_to_Clamp_2.PNG
  16169   Tue Jun 1 14:26:23 2021 JordanUpdateSUSCoM to Clamping Point Measurement for 3" Adapter Ring

After changing the material of the Balance Mass from 6061 Al to 304 Steel, and changing the thickness to 0.21" from 0.25". The CoM is now 1.11mm below the clamping point.

Koji expected a mass change of ~ 4g to move the mass to 1.1mm. The 6061 mass weighed ~1.31g and the 304 mass weighs 4.1g.

A potential issue with this is the screw used the adjust the position of these balance masses, threads through both the aluminum ring and this now 304 steel mass. A non silver plated screw could cold weld at the mass, but a silver plated screw will gall in the aluminum threads.

Quote:

The current vertical distance between the CoM and the wire clamping point on the 3" Ring assembly is 0.33mm. That is the CoM is .33 mm below the clamping point of the wire. I took the clamping point to be the top edge of the wire clamp piece. see the below attachments.

I am now modifying the dumbell mechanism at the bottom of the ring to move the CoM to the target distance of 1.1mm.

 

Attachment 1: CoM_to_Clamp_Updated.PNG
CoM_to_Clamp_Updated.PNG
  16296   Wed Aug 25 08:53:33 2021 JordanUpdateSUS2" Adapter Ring for SOS Arrived 8/24/21

8 of the 2"->3" adapter rings (D2100377) arrived from RDL yesterday. I have not tested the threads but dimensional inspection on SN008 cleared. Parts look very good. The rest of the parts should be shipping out in the next week.

Attachment 1: 20210824_152259.jpg
20210824_152259.jpg
Attachment 2: 20210824_152259.jpg
20210824_152259.jpg
Attachment 3: 20210824_152308.jpg
20210824_152308.jpg
  16305   Wed Sep 1 14:16:21 2021 JordanUpdateVACEmpty N2 Tanks

The right N2 tank had a bad/loose valve and did not fully open. This morning the left tank was just about empty and the right tank showed 2000+ psi on the gauge. Once the changeover happened the copper line emptied but the valve to the N2 tank was not fully opened. I noticed the gauges were both reading zero at ~1pm just before the meeting. I swapped the left tank, but not in time. The vacuum interlocks tripped at 1:04 pm today when the N2 pressure to the vacuum valves fell below 65psi. After the meeting, Chub tightened the valve, fully opened it and refilled the lines. I will monitor the tank pressures today and make sure all is ok.

There used to be a mailer that was sent out when the sum pressure of the two tanks fell <600 psi, telling you to swap tanks. Does this no longer exist?

  16326   Tue Sep 14 16:12:03 2021 JordanUpdateSUSSOS Tower Hardware

Yehonathan noticed today that the silver plated hardware on the assembled SOS towers had some pretty severe discoloration on it. See attached picture.

These were all brand new screws from UC components, and have been sitting on the flow bench for a couple months now. I believe this is just oxidation and is not an issue, I spoke to Calum as well and showed him the attached picture and he agreed it was likely oxidation and should not be a problem once installed.

He did mention if there is any concern from anyone, we could take an FTIR sample and send it to JPL for analysis, but this would cost a few hundred dollars.

I don't believe this to be an issue, but it is odd that they oxidized so quickly. Just wanted to relay this to everyone else to see if there was any concern.

Attachment 1: 20210914_160111.jpg
20210914_160111.jpg
  16364   Wed Sep 29 09:36:26 2021 JordanUpdateSUS2" Adapter Ring Parts for SOS Arrived 9/28/21

The remaining machined parts for the SOS adapter ring have arrived. I will inspect these today and get them ready for C&B.

Attachment 1: 20210929_092418.jpg
20210929_092418.jpg
  16419   Thu Oct 21 11:38:43 2021 JordanUpdateSUSStandoffs for Side Magnet on 3" Adapter Ring SOS Assembly

I had 8 standoffs made at the Caltech chemistry machine shop to be used as spacers for the side magnets on the 3" Ring assembly. This is to create enough clearance between the magnet and the cap screws directly above on the wire clamp.

These are 0.075" diameter by .10" length. Putting them through clean and bake now.

Attachment 1: Magnet_Standoffs.jpg
Magnet_Standoffs.jpg
  16494   Wed Dec 8 10:14:43 2021 JordanUpdateVACPumping down the RGA section

After an overnight pumpdown/RGA warm up, I took a 100 amu scan of the RGA volume and subsequent pumping line. Attached is a screenshot along with the .txt file. Given the high argon peak (40) and the N2/O2 ratio, it looks like there is a decent sized air leak somehwere in the volume.

Are we interested in the hydrocarbon leak rates of this volume? That will require another scan with one of the calibrated leaks opened.

Edit: Added a Torr v AMU plot to see the partial pressures

Quote:

So that Jordan can run the RGA scan this afternoon, I ran TP3 and started pumping down the RGA section.

Procedure:
- Same 1~4
- Same 5
- 6 Opened only the backing path for TP3
- 7 Turned on TP3 only

- TP3 reached the nominal full speed @75kRPM

- 11 Opened V5 to pump the pump spool -> Immediately reached P3<1e-4
- 12 Opened VM3 to pump the RGA section -> Immediately reached P4<1e-4

The pumps are kept running. I'll come back later to shut down the pumps.
=> Jordan wants to heat the filament (?) and to run the scan tomorrow.
So we decided to keep TP3 running overnight. I switched TP3 to the stand-by mode (= lower rotation speed @50kRPM)

 

 

Attachment 1: 40m_RGAVolume_12_8_21.PNG
40m_RGAVolume_12_8_21.PNG
Attachment 2: 40m_RGAVolume_Torr_12_8_21.PNG
40m_RGAVolume_Torr_12_8_21.PNG
  16508   Wed Dec 15 15:06:08 2021 JordanUpdateVACVacuum Feedthru Install

Jordan, Chub

We installed the 4x DB25 feedthru flange on the North-West port of ITMX chamber this afternoon. It is ready to go.

  16634   Mon Jan 31 10:39:19 2022 JordanUpdateVACTP1 and Manual Gate Valve Removal

Jordan, Chub

Today, Chub and I removed TP1 and the failed manual gate valve off of the pumping spool.

First, P2 needed to be vented in order to remove TP1. TP1 has a purge valve on the side of the pump which we slowly opened bringing the P2 volume up to atmosphere. Although, this was not vented using the dry air/N2, using this purge valve eliminated the need to vent the RGA volume.

Then we disconnected TP1 foreline, removed TP1+8" flange reducer, then the gate valve. All of the removed hardware looked good, so no need to replace bolts/nuts, only needs new gaskets. TP1 and the failed valve are sitting on a cart wrapped in foil next to the pumping station.

Attachment 1: 20220131_100637.jpg
20220131_100637.jpg
Attachment 2: 20220131_102807.jpg
20220131_102807.jpg
Attachment 3: 20220131_102818.jpg
20220131_102818.jpg
Attachment 4: 20220131_100647.jpg
20220131_100647.jpg
  16643   Thu Feb 3 10:25:59 2022 JordanUpdateVACTP1 and Manual Gate Valve Install

Jordan, Chub

Chub and I installed the new manual gate valve (Nor-Cal GVM-6002-CF-K79) and reinstalled TP1. The new gate valave was placed with the sealing side towards the main 40m volume, then TP1 was installed on top and the foreline reattched to TP1.

This valve has a hard stop in the actuator to prevent over torquing.

 

Attachment 1: 20220203_101455.jpg
20220203_101455.jpg
Attachment 2: 20220203_094831.jpg
20220203_094831.jpg
Attachment 3: 20220203_094823.jpg
20220203_094823.jpg
  16717   Wed Mar 9 10:23:28 2022 JordanUpdateVACLeak Testing of New Manual Gate Valve - Attempt #1

Jordan, Chub, Paco

Chub and I went into the lab this morning to leak check the new gate valve after pumping over the weekend. This would be done through the RGA and spraying helium around the newly installed flanges. The RGA is set to monitor the partial pressure of helium versus time and we visually watch for any spikes in pressure to indicate an air leak.

So, I mistakenly thought the gate valve was opened and both sides were being pumped on, this was not the case. The vavle was closed so there was a pressure differential whenI turned the handle it tripped the interlocks and closed V4. I closed VM3 to the RGA volume to prevent the filament from being damaged.

Then the medm screen for the vac controls started flashing rapidly, I closed the window and reopened the controls to find all the panels were white, but we could still see the read only vac screen. So Paco restarted c1vac and the controls were restored. V7 closed, but was then reopened.

We now need to restart pumping with the odd pressure differentials between V4 and VM3.

Plan

- TP2 turned off along with the AUX pump

- VM3 opened to vent RGA volume (RGA turned off, filament cooled)

- Open the manual vent screw on TP1 to bring the RGA+TP1 volume back to atmosphere, now no pressure diff. on V4

- Open V4, restart AUX pump to rough out the volume

- Connect RP1/3 line to the pump scroll, turn on RP1/3 RGA+TP1 volume went to mtorr

- Slowly open the manual gate valve

- Connect AUX pump to TP2 and rough out

- Restart TP2, once at speed open V4, close V6 and turn off RP1/3

Now we are pumping on the RGA/TP1 volume with TP2, leak check attempt #2 will happen tomorrow morning

  16721   Thu Mar 10 09:39:59 2022 JordanUpdateVACLeak Testing of New Manual Gate Valve - Attempt #2

This morning Chub and I leak checked the manual gate valve with the RGA and helium. There was no change in the helium partial pressure while spraying helium around the flanges, all looks good.

 

I also took a 100 AMU analog scan, after the filament had warmed up overnight and the plot was quite noisy even with the lowest scan speed. I recommend this unit go back to SRS for a filament replacement/recalibration. I am worried yesterday's "vent" of the RGA volume may have burned the filament. See the comparison of yesterday's analog scan to today's below.

Attachment 1: 3-09-2022.PNG
3-09-2022.PNG
Attachment 2: 3-10-2022.PNG
3-10-2022.PNG
  16772   Tue Apr 12 09:05:21 2022 JordanUpdateVACNew Pressure Gauge Install/Pump Spool Vent

Today, Tega and I would like to vent the pump spool an dinstall the new FRG-400 Agilent Pressure Gauges (per elog 15703). The attached picture shows the volume needed to be vented highlighted in red, and the gauges that need to be replaced/removed (purple dot next to the name).

The vent plan is as follows:

Open RV2

Open VM3

Open V7

Open V4

Shut down TP2

Install new gauges

Will add to post with updates post vent.

Attachment 1: Screenshot_2022-04-12_08-42-33.png
Screenshot_2022-04-12_08-42-33.png
Attachment 2: 81CB0936-1B19-4722-8A32-C3DC1D1FBC21.heic
Attachment 3: 2262ECEF-6200-4E95-8E32-C83CB9EB4F17.heic
Attachment 4: B5712B34-ECF6-43BE-BCB2-38CD775CF653.heic
Attachment 5: BEE14A07-976A-45C2-82A0-1774D377941E.heic
Attachment 6: 84557D6E-6AAE-47CF-A3AD-1DF329FEB550.heic
  16777   Thu Apr 14 09:04:30 2022 JordanUpdateVACRGA Volume RGA Scans

Prior to venting the RGA volume on Tuesday (4/12/2022) I took an RGA scan of the volume to be vented (RGA+TP1 volume+Manual Gate Valve) to see if there was a difference after replacing the manual gate valve. Attached is the plot from 4/12/22, and an overlay plot to complare 4/12/22 to 12/10/2021, when the same volume was scanned with the old (defective) manual gate valve.

There is a significant drop in the ratio O2 compared the the nitrogen peak and reduced Argon (AMU 40) which indicates there is no longer a large air leak.

12/10/21 N2/O2 ratio ~ 4 (Air 78%N2 / 21%O2)

4/12/22 N2/O2 ratio ~ 10      

There is one significant (above noise level) peak above AMU 46, which is at AMU 58. This could possibly be acetone (AMU 43 and 58) but overall the new RGA Volume scans look significantly better after the manual gate valve replacement. Well done!

Attachment 1: 40mRGA_Overlay.pdf
40mRGA_Overlay.pdf
Attachment 2: RGAVolume_4_12_22.PNG
RGAVolume_4_12_22.PNG
  16806   Fri Apr 22 14:14:33 2022 JordanUpdateVACTP3 Forepump tip seal replacement

Jordan, JC

While the pumpspool is vented, I thought it would be a convenient time to change out the tip seal on the TP3 forepump. This one had not been changed since 2018, so as preventative maintence I had JC remove the pump and begin cleaning/installing the new tip seal.

Unfortunately the tip seal broke, but I have ordered another. We should have this pump ready to go late next week. If one is needed sooner, there is a spare IDP 7 pump we can install as the TP3 forepump.

Attachment 1: IMG_0572.jpeg
IMG_0572.jpeg
Attachment 2: IMG_0573.jpeg
IMG_0573.jpeg
  16822   Mon May 2 10:00:34 2022 JordanUpdateVACTP3 Forepump tip seal replacement

[JC, Jordan]

Jordan recieved the new tip seal Friday afternoon and I continued the replacement process in the morning. Finishing up, we proceeded to test the pump in the Clean and Bake room. The pump's pressure lowered to 110 mTorr, and we continue pumping so the seal can recieve a good fitting.

Update: We have confirmed the pump is working great and have reinstalled this back into the vacuum system.                                                                                                                   Note: The same O-Rings were used.

Quote:

Jordan, JC

While the pumpspool is vented, I thought it would be a convenient time to change out the tip seal on the TP3 forepump. This one had not been changed since 2018, so as preventative maintence I had JC remove the pump and begin cleaning/installing the new tip seal.

Unfortunately the tip seal broke, but I have ordered another. We should have this pump ready to go late next week. If one is needed sooner, there is a spare IDP 7 pump we can install as the TP3 forepump.

 

  10279   Sat Jul 26 15:30:15 2014 Joseph AreedaUpdateComputer Scripts / ProgramsNDS2 server propem on megatron

The NDS2 server on megatron was unresponsive for what i think was the last couple of days.

The NDS the log file (~nds2mgr/logs/nds2-201407151045.log) started reporting "Stage: parser output queue is full." at 2014.7.24 14:47:54 also there are 16 connections still not closed with LindmeierLaptop.cacr.caltech.edu (131.215.146.102) with 15 of them in CLOSE_WAIT. 

To identify these zombie sockets we use "netstat -an | grep 31200"

The server was in a condition that /etc/init.d/nds2 stop didn't work and the process had to be manually kill -9'ed and then about 3 or 4 minutes later the zombie sockets were gone at /etc/init.d/nds2 start was used to restart the server.

The LindemejerLaptop was using pynds to get a bunch of channels at once to test drive a streaming visualization code for glitches.  It's unclear whether this bumped into a server limitation.  We have seen similar states in ldvw that seem to be the result of errors which result in client-server connections not being closed properly, leaving data in an output buffer causing Linux to wait for the other side to empty the buffer.

  5254   Wed Aug 17 12:14:27 2011 Josh SmithOmnistructureComputer Scripts / Programs40m summary page plans

Josh Smith, Fabian Magana-Sandoval, Jackie Lee (Fullerton)

Thanks to Jamie and Jenne for the tour and the input on the pages.

We had a look at the GEO summary pages and thought about how best to make a 40m summary page that would eventually become and aligo summary page. Here's a rough plan:

- First we'll check that we can access the 40m NDS2 server to get data from the 40m lab in Fullerton.

- We'll make a first draft of a 40m summary page in python, using pynds, and base the layout on the current geo summary pages.

- When this takes shape we'll iterate with Jamie, Jenne, Rana to get more ideas for measurements, layout.

Other suggestions: Jenne is working on an automated noisebudget and suggests having a placeholder for it on the page. We can also incorporate some of the features of Aidan's 40m overview medm screen that's in progress, possibly with different plots corresponding to different parts of the drawing, etc. Jenne also will email us the link of once per hour medm screenshots.

 

  1221   Fri Jan 9 17:30:10 2009 KakeruUpdateComputersSnapshots of MEDM screens
I wrote a web page which shows snapshots of MEDM screens generated by Yoich's script (e-log #1206).
https://nodus.ligo.caltech.edu:30889/medm/screenshot.html
This page refreshes itself every 5 minutes automatically.

The .html file is generated by /cvs/cds/caltech/statScreen/bin/genHtml.pl
This script generates the .html file contains snapshots listed on /cvs/cds/caltech/statScreen/etc/medmScreens.txt every 5 minutes with cron.
When you wont to display other screens, please edit this .txt file and wait 5 minutes!


To make thumbnails, I wrote /cvs/cds/caltech/statScreen/bin/genThumbnail.pl
This script reads /cvs/cds/caltech/statScreen/etc/medmScreens.txt, too.
(Sometimes, it makes thumbnails with larger storage...)


Quote:
I wrote scripts to take snapshots of MEDM screens in the background.
These scripts work even on a computer without a physical display attached.
You don't need to have X running.
So now the scripts run on nodus every 5 minutes from cron.
The screen shots are saved in /cvs/cds/caltech/statScreen/images/

There is a wiki page for the scripts.
http://lhocds.ligo-wa.caltech.edu:8000/40m/captureScreen.sh

Someone has to make a nice web page summarizing the captured images.
  1225   Tue Jan 13 18:59:09 2009 KakeruUpdateLSCAS CCD centering and ASDD demod phase
I tuned the demod-phase for PRCL and SRCL hand-off, but it have not been optimized enoughly.
I continue this work tomorrow.


Quote:
After Rob's AS beam work, I centered the beam on the AS CCD.
I also optimized the ASDD demod-phase for the MICH signal.
Rob suggested to me that whenever we restart or change the frequency of the DD Marconis, we have to re-optimize the demod-phase
because the initial phase of the Marconi is random. We had the power failure, so it was time to do so.
I confirmed that MICH hand-off from REFL33Q to AS133DDQ is ok.
I will do the same thing for the PRCL, SRCL hand-offs.
  1241   Wed Jan 21 16:18:17 2009 KakeruUpdateLSCAS CCD centering and ASDD demod phase
I tuned the DD demod-pahse for SRM.
It was tuned as the error singnal is to be 0 when the cavity is locked.

The problem is that the good phase changes if MICH and PRM are handed to DD or not.
This may be a result of the demod-phase of these two signals are tuned to be maximise the error signal, not to be 0-offset.

I will tune these two demod-phases, and write a script to tune.


Quote:
I tuned the demod-phase for PRCL and SRCL hand-off, but it have not been optimized enoughly.
I continue this work tomorrow.


Quote:
After Rob's AS beam work, I centered the beam on the AS CCD.
I also optimized the ASDD demod-phase for the MICH signal.
Rob suggested to me that whenever we restart or change the frequency of the DD Marconis, we have to re-optimize the demod-phase
because the initial phase of the Marconi is random. We had the power failure, so it was time to do so.
I confirmed that MICH hand-off from REFL33Q to AS133DDQ is ok.
I will do the same thing for the PRCL, SRCL hand-offs.
  1249   Fri Jan 23 12:48:12 2009 KakeruUpdateoplevsarm cavity oplev calibration
I calibrated optlevs of x and y arm cavity, indipendently from Peter's work.

ITMX pit: 77 microrad/ct
ITMX yaw: 73 microrad/ct
ETMX pit: 280 microrad/ct
ETMX yaw: 263 microrad/ct

ITMY pit: 120 microrad/ct
ITMY yaw: 93 microrad/ct
ETMY pit: 280 microrad/ct
ETMY yaw: 270 microrad/ct

This result is similar to Royal's one (within 30% difference except for ETMX pit), but different from Peter's in ETMY.

The attached figure is the data and fitted curve of ITMX pit.
I took this data for 8s, with 4 Hz excitation.
Attachment 1: ITMX_pitch.png
ITMX_pitch.png
  1259   Thu Jan 29 17:24:41 2009 KakeruUpdateoplevsarm cavity oplev calibration
I calibrated optlevs again. My previous work has a lot of mistakes, so ignore it.

ITMX pit: 195 microrad/ct
ITMX yaw: 185 microrad/ct
ETMX pit: 303 microrad/ct
ETMX yaw: 296 microrad/ct

ITMY pit: 192 microrad/ct
ITMY yaw: 141 microrad/ct
ETMY pit: 294 microrad/ct
ETMY yaw: 301 microrad/ct

(For ITMY, the data is low quality)

My calcuration and Peter's(based on Royal's report) is different in two point.
i) Royal uses some geometrical factor to calibrate ITM.
ii) Royal fits data to exp(-a^2/(2*w0^2)), and I fit data to exp(-a^2/w0^2).

When I calculate with modification of these differences, my result became almost same value of Peter's one.
Now we are discussing which equation is correct.


But we must do some laser works before it...
  1262   Fri Jan 30 19:38:57 2009 KakeruUpdatePSLISS Bad
Kakeru, Peter

We try to improve ISS bord, but there isn't circuit diagram with correct parameters.
We are to measure transfar function and guess each parameter before we desogn new circuit parameters.
  1277   Fri Feb 6 09:52:35 2009 KakeruUpdatePSLCurrent shunt transfar function

I attach the transfar function of the current shunt.
There is a little gap at 10 Hz for phase, but it is a ploblem of measurement and not real one.
 

Attachment 1: TF_CS_gain.png
TF_CS_gain.png
Attachment 2: TF_CS_phase.png
TF_CS_phase.png
  1278   Fri Feb 6 09:56:11 2009 KakeruUpdatePSLISS servo transfar function

I attache the transfar function of ISS servo.

The 4th stage and variable gain amplifier has alomost same transfar function, so their lines pile up.

Attachment 1: TF_ISSservo_gain.png
TF_ISSservo_gain.png
Attachment 2: TF_ISSservo_phase.png
TF_ISSservo_phase.png
  1279   Fri Feb 6 10:46:40 2009 KakeruUpdatePSLISS servo and noise
I measured the output noise of eache stage of ISS servo, and calcurated the noise ratio between input and 
output of each stage.
Generaly, each noise ratio corresponds to their transfar function. This means servo filter works well, not 
adding extra noise.

I attache example of them.
For 2nd stage, the noise ratio is smaller than transfar function with a few factor. This is because the 
input noise is coverd by analyser's noise and ratio between output and input looks small.
This means the input noise of 2nd stage was enough small and all stage before 2nd stage work well
Attachment 1: ISS_servo_TF_noise.png
ISS_servo_TF_noise.png
  1289   Tue Feb 10 23:36:25 2009 KakeruUpdatePSLPA current and laser output
I changed the PA current and measured laser output power (monitor PD signal).
The gain of ISS is 13dB
Attached figure is the relation of PA current and the average and standard diviation of laser output.
The average of output power decreas as current increase. It looks something is wrong with PA.
When current is -0.125, 0, 0.5, ISS become ocsilating. This looks to be changed from previous measurement.

I wrote matlab code for this measurement. The code is
/cvs/cds/caltech/users/kakeru/scripts/CS_evaluate.m
This function uses
/cvs/cds/caltech/users/kakeru/scripts/moveCS.m
Attachment 1: PA_current_output.png
PA_current_output.png
  1295   Wed Feb 11 23:51:53 2009 KakeruUpdatePSLPA current and laser output
I attached a plot of ISS monitor PD and MOPA output to PA current.
The both end of PA current (26.0353[A] and 28.4144[A]) correspond to the slider value of -2.0 and 1.0 .
It looks that we must use MOPA with PA current below 27.5[A].
Attachment 1: PA_current_output.png
PA_current_output.png
  1299   Thu Feb 12 18:35:10 2009 KakeruConfigurationPSLPA current limitter


I added a PA current limiter.
It is only a voltage devider (composed with 3.09k and 1.02k resiste) between DAC and PA current adjustment input.
The output range of DAC is +/- 10[V] and  the conversion factor of PA current adjustment is 0.84[A/V] (measured value), so the PA current adjustment is limited +/- 2.1[A] ( 10[V]*1.02k/(1.02k+3.09k)*0.84[A/V] ).


Actually, the manual of the PA tells that the conversion factor is 0.25[A/V].
There is 3 possibility.
1) There are some mistakes in channels of digital system.
2) The PA manual is wrong.
  2-1) The conversion factor of current adjustment is wrong.
  2-2) The conversion factor of current monitor is wrong.
I measured the signal of current adjustment and current monitor directly, and confirm that they are consistent to the value monitord from MEDM.
Hence the PA manual must be wrong, but I don't know which factor is wrong (or both?).
If the suspect 2-2) is guilty, it means we adjust PA current with very small range.
This is a completly safety way, but a wast of resource.


Now, the slider to control current adjustment indicate the output of DAC.
I will improve this to indicate  current adjustment input, but it takes some time for me to learn about EPICS.

  1328   Fri Feb 20 01:54:18 2009 KakeruUpdateComputer Scripts / Programstdsdata might have a bug

I found a strange jump of value in my data taken with tdsdata.
I couldn't find same jump in a playback of DataViewer, so I think this is a problem of tdsdata.
Be careful when you use tdsdata!

The attached file is an example of jumped data.
I try to get data with allegra and op440m, and both has same kind of jump.
(A downsampling or interpolation may be wrong.)

Rana said there is a fixed version of tdsdata in some PC, but 64bit linux may not have.
I try it tomorrow.

Attachment 1: jumped_data.png
jumped_data.png
  1362   Thu Mar 5 23:18:38 2009 KakeruConfigurationComputerstdsdata doesn't work
I found that tdsdata doesn't work.

When I star tdsdata, he takes a few ~ 10 seconds of data, and he dies with a message "Segmentation fault".
I tried to get data for some times and some channels, and this problem was observed everytime.
I also tried tdsdata on allegra, op440m and mafalda, and it didn't work on all of them.

Yesterday, I got a new version of tdsdata (which modified the problem of Message ID: 1328) and tried to build 
thme on my directory (/cvs/cds/caltech/users/kakeru.....)
This may have some relation to this problem.
ELOG V3.1.3-