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Archive for October, 2008

Email watch

Friday, October 31st, 2008

One of my early posts (six months ago is ancient history, you know) was about the volume of email that I receive.  Large volumes of email make me cranky.  Now, I haven’t clocked it in any serious way, but it seems to me that the email rate has been going down over the last few weeks.  Why might this be?

  • I could be sending less email myself, and thus getting fewer responses.  I don’t think that’s the case, and anyhow most of my email comes through various lists that I’m subscribed to.
  • Everyone has adopted better email habits, not replying to a message unless they have something particularly important to add, or not starting up threads without good reason.  Seems unlikely.
  • People are taking it slightly easier in light of the LHC delay?

That’s an interesting one.  There was a huge buildup in effort and excitement as we headed into September.  How do we maintain the effort we need to bring these experiments online, while also making sure that people don’t get burned out before we even have colliding beams?  How do we make sure that run the detector regularly, so that we can get data for systems debugging and make tests of different conditions while also not having people take so many shifts that they just don’t have it in them to do more six months from now?  These are real concerns, and I’m sure that our managers are thinking hard about them.  My advice to people is to be sure to take that week off if you need to — we need everyone to be well-rested and enthusiastic as we move into 2009, and we get ready for the real excitement to come.

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216 million events

Monday, October 27th, 2008

Today marked the end of the combined running (using the entire detector as it would be for recording collisions data) of the ATLAS detector for 2008. Unfortunately the running didn’t include any time with collisions this year, but as you can see in the image, we have still been recording tons of data recently.  The blue line is the sum of all the events recorded by ATLAS in days since September 13.  “Events” are just snapshots taken at one moment by the detector.

The last few weeks were devoted to getting as much high quality cosmic-ray data recorded as possible, while the detector was still “all in one piece”.  Over the next few months, there will still be data recorded, but more often with a few pieces at a time, and usually some piece off for maintenance at any moment.

The data that was just recorded will be analyzed for the next few months to calibrate the detector and get ready for collisions in 2009.  The total number of events recorded in the last 44 days was 216 million.  That works out to about 57 events recorded per second, every second of the day, for 44 days straight.  Each event is a megabyte or so, so we are talking hundreds of terabytes of data written out.  You can also see, it wasn’t a constant 57 events per second.  There was a week where about half the total data was recorded that was much faster during some special running to accumulate data for the inner detector calibration.

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Telling the world about CMS

Wednesday, October 22nd, 2008

Yesterday’s big event was the LHC official inauguration, at which I was present to represent CMS to the various delegations. This was a great experience, it is very interesting to meet the people who make decisions about how we are funded and explain (hopefully in a successful way) why the studies we will do at the LHC are essential for the understanding of how nature and the universe work. (more…)

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LHC Inauguration LIVE!

Tuesday, October 21st, 2008

You may have already been watching this all day but the LHC inauguration is being webcast live — but if you weren’t, you’ve already missed alpinekat and crew, who rocked.

And it just occurred to me that alpinekat and the Canettes Blues Band are all ATLAS people.  Needless to say, I’ve been to some pretty good ATLAS parties over the last couple of years…

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Take the Helm, Mr. Chekov

Monday, October 20th, 2008

Seth on Pixel Data Aquisition shiftAuthor’s note: This entry is mostly for my mother. If it happens to amuse anyone else, this is purely by coincidence. Also, there is no need to leave comments informing me that I’m an enormous nerd; I have noticed.

It’s true, life here at CERN is pretty much like Star Trek, or at least it looks that way sometimes. After training last month, and some very hectic shifts earlier this month, I’ve finally had a chance to get a picture of myself at the Pixel Detector operation station in the ATLAS control room. I have lots of screens with technical information in front of me, and the front of the room has a full seven projection screens.

Driving the Pixel Detector is not exactly like driving the USS Enterprise, of course. Where they have a navigator and a helmsman helmsperson, we have a shifter who does Detector Control and one who does Data Acquisition. (I do the latter, although I plan eventually to qualify for both so I can operate the whole thing when everything is very stable.) While they do things like “pivot at warp 2” or “reroute auxilliary power through the main deflector dish to produce a tachyon pulse,” we are more likely to “disable a Read Out Driver to re-enter ATLAS combined running” or “consult the data quality shifter about low statistics in the ID cosmic data stream.” The Pixel Detector has a Shift Leader, who’s sort of like the captain, but they’re only around some of the time if nothing exciting is happening. And of course the Pixel shifters are part of a much larger shift crew, which dwarfs the number of people it apparently takes to operate a starship.

Ok, it’s not that much like Star Trek after all, but — dare I say it? — it’s actually cooler, because it’s real.

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On science education spending

Sunday, October 19th, 2008

Even across an ocean, people at CERN spend a lot of time talking about the US elections. A lot of us are American, and many non-Americans consider the election vital to their own countries’ well-being. We’ve been watching the debates on youtube, and reading our favorite websites, like Nate Silver’s fivethirtyeight. He explains what he’s doing with the polling data in detail that’s really appealing to geeks like us. 🙂

When I had lunch with Ken this week, some friends joined us and we spent a lot of the lunch talking about the election. At some point, Ken said, “OK, OK, I know about all this stuff… tell me more about what’s going on at CERN.” It’s fairly likely that he could have been having the same discussion back at his university in Nebraska, and he came to CERN to get caught up on things here instead. I can’t blame him — sometimes I feel like the election is taking up a lot of my brain.

One detail that I’ve gotten a few emails about this week was the now-famous “$3 million overhead projector” that McCain has referred to in the last two debates. Scientists everywhere are spreading the story that the projector is not a simple one used in a classroom — it’s the projector that creates the night sky at the Adler Planetarium in Chicago. The planetarium is a National Historic Landmark, the first planetarium in the Western hemisphere when it was built. I’ve been there, to see Lisa Randall give a talk when she was touring around for her book “Warped Passages.” It’s an awesome place. You can read more about the debate controversy here.

overhead projector?
Image from Alder Planetarium press kit

People are certainly free to disagree whether federal or local or private funds should cover projects like this one, visited by millions of people including schoolchildren from many states and countries. One thing that’s clear to me, though, is that it is *not* a waste of money.

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The view from here

Friday, October 17th, 2008

As I write, it is Friday afternoon in Geneva, and from my hostel room I can see Mont Blanc.  It’s often cloudy around Geneva, and it’s not always clear enough to see it.  This was my one opportunity for this trip.

Despite all my complaints about how hard it is to get here and how disruptive it is back home, it is still nice to be here.  The experiment does seem more real when you are this much closer to it.  It’s not just a few of us around the university talking about what’s going on; here there are people all around focused on where we are and what we need to do.  So yes, I will be back again (probably in the spring).

I think we did manage to bring out some interesting issues during the computing meetings this week.  Yesterday I chaired a session about how things are going with the use of the Tier-2 computing sites.  As we try to roll out the distributed analysis model, just how is it working out for the sites, and, more importantly, for the physicists that are starting to use them more intensively?  We had reports from both sites and physics groups, and (unsurprisingly) many of each cited the same problems over and over.  We also learned about some things that the physics groups want and didn’t realize that we were already working on (or have already provided!); things that they want and that we’re going to have to gently say “no” to; and things they want that are legitimate use cases that require further consideration.  I still need to sit down and summarize everything that got discussed, but it will help set our agenda for the upcoming weeks, and everyone agreed that we need to do this more often.

Now that the DG’s report on the 9/19 incident is out, people have been trying to interpret what it means for us.  Hard to say yet; obviously it will take a lot of effort to do the magnet replacements and so forth as described in the report.  We’re still going to focus on having the detector (and everything else!) ready for May, which is the soonest we could imagine the machine being ready.  From talking to people here, my sense is that people are of course disappointed by the delay, but no one is in a panic.  Which is good.

So, off for some dinner in France tonight, then I have a noon flight to Amsterdam and then Minneapolis and Lincoln tomorrow.  By my calculation, it will be about 20 hours door to door.  Yawn.

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An Official Word

Thursday, October 16th, 2008

CERN has released an interim report on the 9/19 incident:

http://press.web.cern.ch/press/PressReleases/Releases2008/PR14.08E.html

Interesting reading, especially the full report posted here:

https://edms.cern.ch/file/973073/1/Report_on_080919_incident_at_LHC__2_.pdf

It includes a detailed primer on the LHC configuration and layout, which is essential for understanding where the problem started (an electrical bus between two magnets) and how it spread to the cryogenic system.

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As seen on TV

Thursday, October 16th, 2008

Unless you too are one of the millions of people contacted by my mother, you may not have noticed that several of your (ahem) favorite bloggers and former bloggers appeared in a “60 Minutes” segment a few weeks ago on the LHC. If you missed it, you can view the segments on cnet, in particular the Americans at the LHC portion.
Until Monica comes out of blogging retirement, I guess we won’t know what she thought of it, but for me it was partly fun and partly harrowing. I’m probably as vain as the next person, so showing up on a highly respected nationally televised news program was a kick – I have even been approached (only once) by a complete stranger on the subway who said “you’re famous”, which was a bit unnerving really. And my aforementioned mother was really excited. On the other hand, when we actually did the interview we just sat there and talked to them for about 20 minutes, and had no idea what of that material they would air and when. Fast forward a few months, and there’s considerable hoopla being made of the event in my department and in general, and we still had no idea what would actually be shown, and didn’t find out until we saw it with everyone else. From my perspective, it came out fine, but it was a little like tightrope walking without a net. But now my kids’ soccer teammates (as well as my own soccer teammates – Go Fossils!) are asking all about Particle Physics and what it’s all about, which is really the goal for me, so alls well that ends well. Let’s just hope we don’t end up here.

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Life in the Fishbowl

Wednesday, October 15th, 2008

There has been quite a lot of activity at the ATLAS site this week. I don’t mean the physicists, I mean the construction workers. The result is a new entrance area to the building that houses the ATLAS control room, just in time for the big inauguration next Tuesday.

The new entrance area has mostly glass walls, and you can see in the photo (thanks Richard!) that it looks into the ATLAS control room (also visible on this web cam which updates every 5 minutes).  You might also see that not only does it look into the ATLAS control room, it is approximately 3 feet from where I usually sit.  This means visitors will be staring at me and my colleagues from 3 feet away while we work.

For most people in the control room, this fishtank configuration is an improvement because there have often been visitors walking through the control room taking flash photographs (I assume this means visitors will no longer be allowed in).  For those of us at the liquid argon calorimeter desk, it might be a little distracting.  But maybe they will feed us…

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