Displaying reports 71581-71600 of 83397.Go to page Start 3576 3577 3578 3579 3580 3581 3582 3583 3584 End
Reports until 10:22, Monday 02 June 2014
LHO General
justin.bergman@LIGO.ORG - posted 10:22, Monday 02 June 2014 (12170)
morning meeting

LVEA transitioned to laser SAFE

Teams taking fiducial measurements (ITMs/ETMs/OpLevs)

Ready to vent all three corner station volumes after lunch

Good results from Thomas measurements on the stability of RH over the weekend

HAM4/5 doors and HAM6 septum in place

HAM6 SLED ready to install, on hold for now

need visual inspect on HAM6 cabling lengths

Apollo restoring beer garden cleanroom---coupling with BSC1/3

installation of TCS table stops on hold

need to lock HEPI for BSC1/3 due to potential contact with HEPI crossbeams

need to protect TCS mirrors during in chamber work

H1 General
travis.sadecki@LIGO.ORG - posted 10:17, Monday 02 June 2014 (12169)
Particulate Mobility Experiment is running again

The particulate mobility experiment that is mounted to HAM 3 is back up and running.  It will be running for the next 3 days to make sure the entire vent cycle is captured.

H1 ISC (ISC, SUS, TCS)
sheila.dwyer@LIGO.ORG - posted 09:41, Monday 02 June 2014 - last comment - 16:47, Wednesday 04 June 2014(12167)
alignment snapshot, ring heater changes alingment

Betsy, Sheila, Keita, Arnaud, Thomas

Here is a snap shots of the current alingment offsets. This alingment was checked quickly this morning, both of the arms are flashing green so the ITMs are within a urad or so of alinged. 

We noticed that the ailngment of ITMY was off by about 8 urad in pitch from the saved offset, this seems to be because turning on and off the ring heater changes the ailngments.  Attached are trends of the OpLevs durring the ring heater stress test this weekend, the itms moved by 2-5 urad in yaw, and both moved by about 30 urad in pitch. The third screenshot shows how the pitch changed as the ring heater power cycled.

Images attached to this report
Comments related to this report
jeffrey.kissel@LIGO.ORG - 09:50, Tuesday 03 June 2014 (12182)DetChar, SUS, TCS
Link 

@DetChar -- can you grab calibrated ASDs of the optical levers before and after the ring heaters are on full blast? It looks like they not only displace the optic in angle, but also add noise. It would be good to quantify this early, so we can fix it!
aidan.brooks@LIGO.ORG - 11:12, Tuesday 03 June 2014 (12184)
Link 

I forgot to check this. 

https://dcc.ligo.org/LIGO-T1100184
Phil Willems wrote a document (T1100184) that predicted around 0.9urad of pitch per Watt of RH power. We applied 27W of power, so the Spurious Willems Pitch is around 24urad. This seems consistent with what was seen. It's worth a more detailed look though.

I can't explain the 8urad offset between the start and finish.
laura.nuttall@LIGO.ORG - 14:37, Tuesday 03 June 2014 (12190)
Link 

From Jeff's request I've taken a look at the Oplevs before, during and after the heaters were on and found their ASDs (1st plot). These ADSs are taken over 10 minutes and the times are noted in the legend. I specifically chose times where the ITMY ISI ODC is reporting a good state. In addition the BLRMs look normal and similar for all three times. I also found the ground motion ASDs for these times (2nd plot) to reconfirm the ground motion is similar for all three times. 

Conclusion - the ASDs for the Oplevs look very similar before, during and after the heaters are on; they don't appear to add extra noise. There is perhaps an extra peak between 7-8Hz in the YAW when the heaters are on but other than that nothing stands out.
Images attached to this comment
shivaraj.kandhasamy@LIGO.ORG - 21:15, Tuesday 03 June 2014 (12197)
Link

There is also a DC power level difference between states before after the weekend stress test. Based on the  channel H1:TCS-C_RH_Y_LOWERCURRENT and Aidan's note of 27 W in the ramp up state, the forementioned DC offset correspond to a power level difference of ~8 W (assuming 0.55 for the current level during stress test and 0.3 before the stress test and 0 after the stress test, obtained from the plot of H1:TCS-C_RH_Y_LOWERCURRENT; 27 * 0.3^2/0.55^2).  From the dcc documnet noted in the Aidan's comment this correspond to ~8 urd difference we between the initial and end states. This also means that we probably have to make new reference with the current setting (of zero current), if desired.

daniel.sigg@LIGO.ORG - 07:26, Wednesday 04 June 2014 (12198)
Link

The ITMY ring heater was set to 8W during the past commissioning period to correct for the fact that we had an ETM with ITM coating installed. This will be changed in the current installation phase. New references will be rquired when we have the new optics installed and aligned.

betsy.weaver@LIGO.ORG - 09:15, Wednesday 04 June 2014 (12200)
Link

Also note, the ITMs that this ring heater test was performed on are hung from metal wires in stead of glass fibers.  I wonder if this is what is making them more susceptible to steering errors when the ring heater is engaged...  The current install is to swap these ITMs out for new units complete with glass fibers.  Hopefully the ITMs won't be as susceptible to mispointing when on fibers if this is the case.

jeffrey.kissel@LIGO.ORG - 15:58, Wednesday 04 June 2014 (12209)COC, DetChar, ISC, SUS, SYS
Link 

J. Kissel

As Betsy indicates these ITMs are suspended via steel wire instead of fused silica fiber. This plays a difference in the compliance used in the Phil's calculation of the expected displacement in T1100184.

Also, the Willems calculation uses a QUAD suspension model from T1000263 which is an out-dated model parameter set that was never confirmed against real measurements (which we now have).  Also it's unclear which Stage / DOF to Stage / DOF was used to produce the "pitch coupling" of 0.154 [rad/Nm]. The mathematica notebook that is "available from the author" is regrettably *not* zipped up in the "Other Files" on the DCC card, so I can't confirm. The attached .pdf doesn't have the 0.154 anywhere in the document.

However, assuming the compliance he used was pitch displacement of the test mass from pitch torque on the test mass, the values from the production quad model model (now confirmed against measurement) are
Fiber: 0.141 [rad/N.m] (using the quadopt_fiber.m parameter set)
Wire: 0.105 [rad/N.m] (using the quadopt_wirerehang.m parameter set)
Willems quotes the displacement of the Center of Mass (CoM) as 1.47e-7 [m] for 11 [W] of ring heater power. Assuming the displacement is linear with ring-heater power (safe assumption??), that's
1.34e-8 [rad/W]
The displacement one expects per Watt of Ring heater power from the Willems model of a displaced CoM is then
Fiber:  1.34e-8 [m/W] * 40 [kg] * 9.8 [m/s^2] * 0.141 [rad/N.m] =  7.4064e-07 [rad/W] = 0.74 [urad/W]
Wire:   1.34e-8 [m/W] * 40 [kg] * 9.8 [m/s^2] * 0.105 [rad/N.m] =  5.5154e-07 [rad/W] = 0.55 [urad/W]

And therefore at max power of 27 [W], the ITMs should be displaced by
Wire: 5.5154e-07 [rad/W] * 27 [W] = 1.4892e-05 [rad] = 15 [urad].

This is a factor of two less than what is seen in ITMX Pitch (the cleanest example). For ITMY, I don't think the test mass was allowed to reach equilibrium before the ring heater's power was changed during the power cycling, so it's more difficult to assess the displacement -- but I think it's much closer to 15 [urad] judging by when the test was turned off (presumably it was turned off to zero current, and not the equivalent of 8 [W] that it had been set to as Daniel indicates).
thomas.vo@LIGO.ORG - 16:47, Wednesday 04 June 2014 (12214)
Link

Jeff pointed out that the factor of two in the ring heater deviation could arise from the optical lever gain in ITMY being a factor of two smaller than ITMX.  We trust the ITMX's optical lever calibration because its gain was measured using the baffle PDs and the entire 4km arm (noted in ALOG 10331) but it doesn't look like a similar procedure was done for ITMY, or at least we couldn't find an ALOG that indicated as such.

H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 09:10, Sunday 01 June 2014 (12163)
CDS model and DAQ restart report, Saturday 31st May 2014

no restarts reported.

H1 TCS
thomas.vo@LIGO.ORG - posted 21:54, Saturday 31 May 2014 - last comment - 23:35, Sunday 01 June 2014(12162)
TCS Ring Heater Test 
D. Hosken, G. Grabeel, T. Vo

We were able to fix the ring heater chassis EtherCAT wiring by referencing the drawings.  We initially turned both ITM ring heaters to 30 Watts at 6:46 PM PT but it seems as though the maximum power that the drivers can put out is ~15-16 Watts so we changed the script that Greg wrote to run the power at 13.5 Watts during the high power portion and .5 Watts in the low power portion.  I'll come in tomorrow morning to run some trends and take some measurements.  John verified in the first hour that there were no spikes in pressure.
Comments related to this report
thomas.vo@LIGO.ORG - 13:58, Sunday 01 June 2014 (12164)
Link 

Here's the past 17 hour trends, there doesn't seem to be much correlation between pressure and ring heater cycling. The test is going to run for about another 5.5 hours or so.

Also, I've plotted one cycle at 17:17 UTC and you can see the voltage rise to a steady state in about 30 minutes or so as we would expect, which means that the temperature of ring heater in question is in fact getting hotter which changes the resistivity and the ring heater driver is reacting to that change.  The current output is noisier and the X_UpperCurrent doesn't seem to follow this trend and I'm not sure why.
Images attached to this comment
aidan.brooks@LIGO.ORG - 18:43, Sunday 01 June 2014 (12165)
Link 

The RH driver is a current source. There's an internal servo that holds the drive current steady - hence it doesn't change as the RH resistivity changes.
thomas.vo@LIGO.ORG - 23:35, Sunday 01 June 2014 (12166)
Link 

Thanks Aidan. We've finished with the test, both ITM RHs are now off.
H1 ISC (INS)
sheila.dwyer@LIGO.ORG - posted 18:08, Saturday 31 May 2014 (12161)
Did not find beam on End X QPDS

It looks like we will need to go in chamber at end X to fins IR on the QPDs.  I searched for the beam today by locking ALS, and moving the picomotor for M4 to toward the position that Kiwamu et al found in February (alog 10091).  This was fine for the Y direction, but in the X direction I only got about a quarter of the way toward the old position before the green transmitted power started to drop.  One theory is that this could be the green clipping on the mount for M4 (TMS table drawing).  After a little bit of searching around, I decided move the picomotors back to the position that we had set them to to restore the beam on the table. 

The positions used to get IR onto the LSC PD from February until yesterday were 9267 X 1665 Y for M4.  Today after moving the picomotor around quite a bit, I needed to use 27357 for X and -12616 for Y to restore the beam to the same position.  So these numbers are meaningless as references. 

If you remove the snout from the LSC TRX PD in air, there are two brighter green spots (with two very faint spots below them to form a square, right now the lower ones are clipped upstream).  The one that is slightly brighter and on the side of the PD face that is closer to the chamber is the one that is co-linear with the IR, and could be used as a reference if we decide to send IR into the chamber from this path to align the QPDs. 

H1 ISC
keita.kawabe@LIGO.ORG - posted 16:59, Saturday 31 May 2014 (12160)
EX WFSA beam clipping fixed

Yesterday Daniel noticed that the beam was clipped on EX WFSA, but the beam was not centered either and we were in the middle of IR beam finding. Today I centered the beam and it was still clipped because the beam was coming to the WFS head at much shallower angle than it should be. I fixed it by tilting the WFS head.

H1 ISC
keita.kawabe@LIGO.ORG - posted 16:48, Saturday 31 May 2014 (12159)
Another EY WFS whitening chassis swap (Daniel, Keita)

I and Daniel went to EY and tested WFSB using AM laser, and we saw that some of the channels were a factor of 5 or so smaller than the others.

Eventually we tracked it down to the WFSB whitening chassis (S1101602) though I thought it was working OK on Thursday (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=12138),

We tested S1101601 that was pulled out earlier this week that was suspicious unit but was never conclusively diagnosed bad, and it didn't work. So we got another spare unit (S1101638) from the corner station and  put it in.

What are in use now: S1101600 for WFSA, S1101638 for WFSB.

Bad units: S1101601, S1101602, S110163.

Bad ones are put on a table in EY.

LHO VE
kyle.ryan@LIGO.ORG - posted 11:21, Saturday 31 May 2014 (12157)
RGA @ BSC7 is OK - logging scans 


			
			


		
		


		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		
		


			
			


				 H1 CDS 
(DAQ)				
				


			
			


			
			

			
			


		
		


		
		


			david.barker@LIGO.ORG - posted 10:54, Saturday 31 May 2014 (12156)
			
			


		
		


		
		


			CDS model and DAQ restart report, Friday 30th May 2014
			
			


		
		


		
		


			

	model restarts logged for Fri 30/May/2014

	2014_05_30 14:42 h1fw0



	unexpected restart of h1fw0


			
			


		
		


		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		
		


			
			


				 H1 SYS 
				
				


			
			


			
			

			
			


		
		


		
		


			rainer.weiss@LIGO.ORG - posted 20:48, Friday 30 May 2014  - last comment - 13:20, Thursday 05 June 2014(12155)
			
			


		
		


		
		


			Vibration Measurements of the beamtube
			
			


		
		


		
		


			
John Worden, R. Weiss
Vibration measurements of the beamtube with the new R10 insulation and aluminum jacket were made and described in the
appended document. The new insulation reduces the acoustic coupling to the beamtube but not as well as the initial insulation.
The data enables a more detailed estimate of the phase noise from the beamtube motion due to the faulty HR coatings of the new 
test mass mirrors. The DCC number of the document is T1400384.


			
			


		
		


		
		


				Non-image files attached to this report
			
			


		
		


		
		


			

				

				
Vibrationmeasurementsofthebeamtube.pdf

			

			
			


		
		


		
		






	
	


		Comments related to this report
		
		


	
	


	
	


		rainer.weiss@LIGO.ORG - 13:20, Thursday 05 June 2014 (12233)
 Link 


		
		


	
	


	
	


		
Error in the document. Please see T1400384-v2 or LHO log entry 12232


		
		


	
	


	
	






		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		
		


			
			


				 H1 ISC 
(IOO, ISC, SEI, SUS)				
				


			
			


			
			

			
			


		
		


		
		


			daniel.hoak@LIGO.ORG - posted 19:02, Friday 30 May 2014 (12154)
			
			


		
		


		
		


			Beams marked
			
			


		
		


		
		


			
Sheila & Dan

We marked the two IM4_TRANS beams (PRM_REFL and IO_TRANS) on the wall of the LVEA today.

To be clear: both of these beams are transmitted through IM4.  One is from the beam leaving the IMC, the other is the reflection coming back from the PRM.  The IO_TRANS beam is in the -X direction on the wall.

We noticed that there are also two green beams very close to the IR beam reflected off the PRM.  Only the Y-arm was locked at the time, so this must be the faint green reflection off of PR2 from the Y-arm.  We might want to use these as a reference for the BS alignment in the future.


			
			


		
		


		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		
		


			
			


				 H1 ISC 
				
				


			
			


			
			

			
			


		
		


		
		


			daniel.sigg@LIGO.ORG - posted 18:00, Friday 30 May 2014  - last comment - 13:23, Saturday 31 May 2014(12153)
			
			


		
		


		
		


			EY WFS
			
			


		
		


		
		


			

	(Keita, Daniel)



	Today we measured and adjusted the gain/phase of the WFS RF signals. WFS_A looks fine, but WFS_B has segments 3 and 4 which are ~10x smaller than 1 and 2. Engaging DOF4 did result in a stable feedbakc but with a rather large offset. We added an offset to segment 4 of WFS_B to recover. Adding DOF3 did not result in a stable feedback.



	Playing around with the individual pit/yaw offsets and the WFS DC centering one can find feedback topologies with all 4 DOFs engaged. However, they are susceptible to disturbances.


			
			


		
		






	
	


		Comments related to this report
		
		


	
	


	
	


		daniel.sigg@LIGO.ORG - 13:23, Saturday 31 May 2014 (12158)
 Link 


		
		


	
	


	
	


		

	For this measurement the WFS offsets are:



	
		

			
				Bias
			
				WFS A
			
				WFS B
		

	
	
		

			
				Pitch
			
				-2500
			
				-1600
		

		

			
				Yaw
			
				-5000
			
				4700
		

	




	 



	 



	 



	First measurement shows an ETMY yaw misalignment by 1 µrad. The power drops by about 15%. The yaw offsets are of order 10,000 counts. We also see a significant pitch ofset. But, more importantly the DC offsets on the WFS heads are also very large. The WFS servo was off during the measurement.



	The second plot shows the effect of moving the picomotor for WFS_B by about 0.2 in yaw and 0.3 in pitch. The resulting offsets are of order 7000. Since the WFS servo was off, there was no degradation of the cavity power.


		
		


	
	






Non-image files attached to this comment
	
	













	
	






		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		
		


			
			


				 LHO VE 
				
				


			
			


			
			

			
			


		
		


		
		


			kyle.ryan@LIGO.ORG - posted 17:58, Friday 30 May 2014 (12152)
			
			


		
		


		
		


			~1715 hrs. local -> Combined BSC7's RGA with the XBM
			
			


		
		


		
		


			
This RGA is set up to scan every 60 minutes for this weekend in order to capture data during the Ring Heater "burn".


			
			


		
		


		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		
		


			
			


				 H1 SUS 
				
				


			
			


			
			

			
			


		
		


		
		


			arnaud.pele@LIGO.ORG - posted 17:13, Friday 30 May 2014 (12151)
			
			


		
		


		
		


			ETMy L2L measurement with ESD
			
			


		
		


		
		


			

	Yesterday night, after Richard re-rerouted the end-y ESD cabling, I took a L2L transfer function to check the length drive with the ESD. It seems to behave nicely, and similarly as EX. The attached plots shows the comparison of Ex and Ey TF in m/cts.



	The measurement was taken using the same dtt template as for ETMx. The arm was locked without the slow control engaged. Sensor used was ALS-Y_REFL_CTRL (in um). Measurement lives in



	/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMY/SAGL3/Data/2014-05-29_H1SUSETMY_L3_L2LPY_SweptSine.xml



	2014-05-29_H1SUSETMY_L3_L2LPY_SweptSine.xml2014-05-29_H1SUSETMY_L3_L2LPY_Swep


			
			


		
		


		
		


				Images attached to this report
			
			


		
		


		
		


			
			
			


		
		


		
		


		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		
		


			
			


				 H1 TCS 
(TCS)				
				


			
			


			
			

			
			


		
		


		
		


			thomas.vo@LIGO.ORG - posted 17:05, Friday 30 May 2014 (12150)
			
			


		
		


		
		


			TCS Progress
			
			


		
		


		
		


			
CO2X
 - Zero-ed out the QPD segments to compensate for the differences in individual quadrants.
CO2Y:
 - Zero-ed out the QPD segments to compensate for the differences in individual quadrants.

HWS:
 - Built up HWS camera for both X&Y sides of the table, able to get serial connection and read out the status information
 - End station HWS table inventory progress: Cables and optics completely kitted.
 - Need a re-do of positioning of the HWS-Y camera because of interference with the table enclosure.

RH:
 - Prepared for a 24 hour ITM ring heater test. 30 minutes on full power (~30 Watts) and 30 minutes off. We'll do this work on Saturday and Sunday.


			
			


		
		


		
		


	
	


	
	


		
		


			
			


		
		


		
		


			
			


		
		


		
		


	
	


	
	


		

		
Displaying reports 71581-71600 of 83397.Go to page 
Start 3576 3577 3578 3579 3580 3581 3582 3583 3584 End