S5 update

Ben Owen
Ben Owen
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Topic 191100

Hi folks,

In LIGO land we've all been running full steam for a while, but it's time for an update.

S5 (the fifth science data run) has been going since early November and is scheduled to last about a year. It was certified (I think by the National Science Board?) as having reached the initial design goal, so we're officially in business.

Roughly speaking, S5 data is about twice as good as S4. That is, the strain noise is half what it was in S4. But there is room for improvement.

First, the duty cycle for triple coincidence (H1, H2, and L1 interferometers all running) wasn't so hot. The main culprit was L1. Before S4, Livingston was down every day due to logging next door. Improved seismic isolation fixed that, but for the first couple of months of S5 they started adding another building right next to the corner station. It's an education and outreach center, full of all sorts of goodies for the general public. That'll be great, but during the day it meant L1 was down even with the new isolation. The building is done, so we're seeing better duty cycle now.

Also, the noise below 100Hz was actually a bit worse than design. That's been slowly improving as some things were caught, but we still don't know what's causing it. Fair bet it's somehow up-conversion of 1-3Hz seismic noise from traffic, since it correlates pretty strongly with the working day and rush hour. Last time I did shifts in the control room was January, and during the day it was enough that we had to lower the laser power to avoid dropping out of lock constantly. One gravel truck wouldn't do it, but two in rapid succession would nail us. One figure of merit is the range to which we could see a signal from a binary neutron star signal. That was peaking at 12 megaparsecs for H1 back in January and dropping to 10 during the day. Now it's up to almost 14 on a good night.

Once the current Einstein@Home analysis finishes, we're probably going to do the same search on S5 data. That is, 30-hour chunks of data (which may span 40 hours of clock time due to dropouts) which require a search of a spindown parameter as well as sky position. But nothing is set in stone. We are still looking at the quality (duty cycle and stationarity) of the first few months of S5 data, and trying to decide if we want to do a longer search this time.

The reason we can contemplate doing that is that more of you have been joining and staying. And the ones running Windows have been a lot faster lately with help from Hungary.

Thanks from all of us,
Ben

Andreas
Andreas
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S5 update

Thanks a lot Ben for the update! It's always good to know what's happening, and also good to know we have plenty of more work to crunch through!

Click my stat image to go to the BOINC Synergy Team site!

Chipper Q
Chipper Q
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Thanks for the update, Ben!

Thanks for the update, Ben! Sounds like good progress all around. Can more improvements be done regarding seismic isolation hardware, or is it something we'll have to live with? What about some sensors closer to the thoroughfares to help with filtering?

AnRM
AnRM
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Thanks for the update, Ben.

Thanks for the update, Ben. It means a great deal to all of us to have some insight into your problems as well as your successes....it keeps the machines running as well....Cheers, Rog.

Mike Hewson
Mike Hewson
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Ah.... What splendid news all

Ah.... What splendid news all round!
As you've 'all been running full steam for a while', please make sure no-one blows a valve. :-)
Officially in business, eh? Spank that NSB! :-)
As for S5 data, I'm ready any time ...
It's very good that 'more of you have been joining and staying', and if LIGO can do more with that then I'd say go for it!
All hail akosf!!!
I'll tell my teenagers to start tiptoe-ing if that will help at all... :-)
Thank you Ben.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Trog Dog
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Perhaps a note about this on

Perhaps a note about this on the home page and a pointer in Crunching and Cafe would help to spread the news. I usually don't read the Science board but I always check the headers just in case something catches my eye as this thread did, but I'm sure there are plenty of forum users that don't check out the Science board.

ExtraTerrestrial Apes
ExtraTerrestria...
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Count another vote for these

Count another vote for these interesting news one on the home page!

MrS

Scanning for our furry friends since Jan 2002

Ben Owen
Ben Owen
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Hi folks, In all the

Hi folks,

In all the excitement I forgot ... there is good news on S5. As of early June the "mystery noise" below 100Hz is pretty much gone from all three interferometers. And with construction finished on the new building at Livingston, the duty cycles are much better than they used to be. We're going for a year of triple coincidence data (all three interferometers in science mode simultaneously), so with dropouts that will take more than a calendar year, but at the present rate S5 should hit its goal in early 2007.

Crunching all that data is another story....

Ben

Nothing But Idle Time
Nothing But Idl...
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RE: Hi folks, In all the

Message 28220 in response to message 28219

Quote:

Hi folks,

In all the excitement I forgot ... there is good news on S5. As of early June the "mystery noise" below 100Hz is pretty much gone from all three interferometers. And with construction finished on the new building at Livingston, the duty cycles are much better than they used to be. We're going for a year of triple coincidence data (all three interferometers in science mode simultaneously), so with dropouts that will take more than a calendar year, but at the present rate S5 should hit its goal in early 2007.

Crunching all that data is another story....

Ben


With all the logging, building construction, road traffic etc, why was this site chosen for L1? Is there something special about it? Why not locate in the desert of New Mexico for example?

KEP
KEP
Joined: 10 Jul 05
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RE: Hi folks, In all the

Message 28221 in response to message 28219

Quote:

Hi folks,

In all the excitement I forgot ... there is good news on S5. As of early June the "mystery noise" below 100Hz is pretty much gone from all three interferometers. And with construction finished on the new building at Livingston, the duty cycles are much better than they used to be. We're going for a year of triple coincidence data (all three interferometers in science mode simultaneously), so with dropouts that will take more than a calendar year, but at the present rate S5 should hit its goal in early 2007.

Crunching all that data is another story....

Ben

Forgive me if I mistake, but it sound like it's time for a real aussia assault to help you once S5 is cleared, and also it looks like you need to start spreading the word of Einstein@home, and thereby try to make yourself more popular than seti... maybe you should try convinsing the crunchers at seti, just waisting a lot of time double crunching data previously crunched, that einstein is a much more worthy cause :)

m.mitch
m.mitch
Joined: 11 Feb 05
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RE: Forgive me if I

Message 28222 in response to message 28221

Quote:
Forgive me if I mistake, but it sound like it's time for a real aussia assault to help you once S5 is cleared, and also it looks like you need to start spreading the word of Einstein@home, and thereby try to make yourself more popular than seti... maybe you should try convinsing the crunchers at seti, just waisting a lot of time double crunching data previously crunched, that einstein is a much more worthy cause :)

Now that's caught the eye of a few people. It's on the table for discussion and in my opinion, not a bad choice for an Aussie Assault!

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