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Steve Nahn | USLHC | USA

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Getting out of the fog…

Monday, January 19th, 2009

Went hiking up the Jura Mountains the other day with my friend Maarten.  Going to the mountains is the only manner of staying sane in Geneve during the grey grey grey grey grey wintertime.  It’s the Brouillard, and sometimes you don’t see the sun for weeks.  Everyone gets grumpy.  But the cure is is just to go up, as we did:

Me, in the Jura not far from La Dole

You can see the soup of clouds behind and below me, underneath which is Geneve and Lac Leman.  We did a little slipping and sliding, but overall had a great time in the sunshine at 1500 meters, when it was dark and dreary at 400 meters.  Just one of the things one does around here when not banging away on the laptop or in a meeting (or both).


A new outlook?

Thursday, January 15th, 2009

So, I’ve been gone a bit (again), sorry.  I’m not sure you really want to hear about my trials and travails in teaching undergraduates Classical Electromagnetism, although a nice story on my class did appear in the New York Times yesterday  (Prof. Sciolla is a colleague, we were teaching two different sections of the same class, and Ms. Rimer visited hers).  I can discuss this TEAL business in another blog, if there is demand.

Made it back to CERN in October briefly, and now during the MIT break in January.  Pretty quiet over here, but I sense after last fall’s exercises in Cosmic Ray running and “almost Beam” running, people are gung-ho to apply what was learned and sharpen our preparations to improve our “readiness for beams”.  This is a good thing.   Exactly when we may see some more beam?  The $1,000,000 question – but there is a workshop in early February which is expected to produce an updated schedule for 2009.  It would be very good to see beam this year.

In the meantime, there’s the continual plight of  Science Funding in the US – noone is quite sure what will happen, but everyone is quite happy about Obama’s science team – Energy Secretary Steve Chu (a fellow member of Project Steve!), Nobelist and Director of LBL certainly is cogniscent of the issues in HEP, and John Holdren, President’s Science Advisor,  also recognizes the importance basic science can play in everybody’s life (even if they don’t realize it).  Before the legislative branch recessed, there was some indication that funding for science would be bundled into the Economic Bailout legislation, but I haven’t heard any update.  Otherwise it is a continuing resolution, which would be bad – I don’t want to go into what bad means, it’ll depress me.

However, two things I caught recently encourage me – first, a document from the National Academy of Science (executive summary for free) which notes the link between National Security and Technology, and among other things finds

US national security and economic prosperity depend on full global engagement in science, technology, and commerce

although most of the note is about export rules, but it does recommend lifting the rather stringent Visa requirements for foreign scientists coming in to the US.  Having had collaborators who spent 5 hours in Border Control after a trans-atlantic flight, and excellent prospects whom we simply could not hire due to Visa restrictions, I can see where this may have a direct benefit on Science, and the demonstration of the benefit of investment in scientific pursuits on other aspects is certainly something to be applauded.

Second was an guest opinion in the New York Times (you can tell how I get my news when I am at CERN, huh?) from Stanford PhD. biologist, who uses the LHC as an example of Big Science – to (mis)use his metaphor, if you want to reach the fruit at the top, you need to build a big ladder.  He is advocating something a little different, Citizen Science, where ordinary citizens gather eg. ecological data for survey purposes, but even the LHC has its own version – LHC@Home, where you can put spare cycles on your home computer to work for LHC.  I think there are even some variants out there, but you can use google, right?  Anyway, the good omen is that scientists outside the arena of Particle Physics are recognizing the reasons behind why “Big Science” is the way our field works, and even seeing how the developments of our field (large scale computing, synchrotrons were his two examples) are benefiting other scientific disciplines which lead to direct ramifications for the public at large.

All this is fairly heartening from my point of view – evidence that we are moving away from a situation where science pursuits were seen as a luxury,  towards the recognition of the cross feeding between different scientific endevours and the realization of the importance of the role science plays in our societal “pursuit of happiness”.


Where ya been, Perfesser?

Tuesday, November 11th, 2008

Ok, Silence may be golden, but this is a bit ridiculous.  Truth is, right now I am back at MIT, busily teaching Electromagnetism to unsuspecting freshmen and upperclassmen who are onto me, giving presentations to Visiting Committees and preparing seminars which when scheduled had the promise of REAL BEAM DATA (see, you’re drooling too!)  but now fall into the category of “what we can do with zillions of cosmic rays” – is is unfair to pooh pooh the 300 million events CMS just collected, which are very useful for us as a dry run, but it just isn’t the same.

Being back here while everyone else is at CERN means I am a virtual presence, attending meetings in my PJs with a cup of coffee at my computer at 7 AM via VOIP, or occasionally getting to work in time to join by real video conference.  There was a surreal moment last week when Josh showed up using his laptop onboard camera:

Someone needs to recomplie his Kernel

No, he’s not from Australia – he claims he needs to recompile the Linux Kernel to get the camera to uninvert, but still, it is pretty strange to see such a thing so early in the morning.

Actually, funny enough, there has been some noise about blogging from the CMS management – apparently they are very concerned about physicists disparaging physicists, or “leaks” about LHC or about new results.  Now, I understand the concerns, but to me it also borders on censorship, and we professors feel pretty strongly about our intellectual freedom – anyway, maybe that is another reason for my lack of spouting off, but anyone who is worried about that ought to have a look at my second blog entry– it isn’t a real result unless it is in a peer reviewed journal.

So, I will continue to blog but if I  make anybody angry, let me know and we can discuss.  Discussion is good – sometimes I’ve had some pretty vigorous and loud ones, and usually I find all participants learn something (unless they are my 11 year old, who decides he isn’t going to learn anything even if it kills him which happens more often than I’d like).


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.


Case dismissed

Monday, September 29th, 2008

Enough said.


You get what you pay for

Thursday, September 25th, 2008

Now, I know that there is impending doom on Wall St and all (How did that happen in fact? Anyone asking that question before we taxpayers bail out the economy?) but as we write Congress is going to consider a continuing resolution since we don’t have an appropriations bill. This means the same funding next year as last year, which was a disaster for science before a “Deus ex Machina” partial recovery that no one wants to relive. Here’s what the president of the American Physical Society has to say:

Congress has not passed any FY 2009 appropriations bills and is now finalizing a Continuing Resolution (CR) that will keep the government operating when the new fiscal year begins on October 1, 2008. The House is expected to consider the bill on Thursday or Friday of this week. The CR, according to the latest information, will remain in effect until March 6, 2009 and would keep all federal programs operating at FY 2008 levels, except those granted waivers. At this time, science is not on the waiver list, and the proposed bill would not include any of the science increases contained in the Supplemental Appropriations bill Congress passed earlier this year. Unless science receives a waiver, the impact will be extraordinarily damaging.


  • Department of Energy user facilities would be forced to cut back operations substantially
  • A new round of layoffs at the national laboratories could occur
  • The number of university grants would be cut, with new, young investigators especially harmed
  • and

  • The U.S. would be forced to cut to near zero its planned contributions to the global fusion energy project, ITER, damaging the nation’s ability to participate in future international scientific collaborations

Another great read is the editorial written by Norman Augustine, chairman of the “Gathering Storm” commission, in the current edition of Science – I’m pretty sure I’d break a few copyright laws by posting it, but if you have access to Science through an online subscription you can have a look– it is a very poignant look at how science funding is going in the US compared to the rest of the world.

I’m preaching to the choir, and perhaps abusing my podium a bit (note, I am trying to be nonpartisan – this is just if you want the US to continue to lead the world in scientific endeavours), but I suggest you write your representatives and tell them how you feel about Science support in the US. It is easy, just start here

OK, step back from the soap box! On a side note, 60 Minutes has a segment on “The Collider” this week which may prove to be interesting (or embarrasing…)


That is how it goes…

Sunday, September 21st, 2008

Hi All-

Welcome to the occasionally exasperating world of pushing the limits of science.  Yes, transformers break (and are repaired within days) and problems occur which also could be fixed in days were it not that they are in parts that operate at about 1 degree above absolute zero, which means repair requires some care and some time.  If you don’t know what I am talking about, have a look at Seth’s blog which does a nice play-by-play.  This sort of thing makes it very hard to plan on the beam, but those of us who have been there before (like at the Tevatron for 8 years) know that this is how it goes.  So do not despair and think the LHC is dead on arrival, it’s just going to take a little while longer.   In fact, for me it means an opportunity to be present at first collisions, which is a bit like icing on the cake in that I’m not crucial for operations, still, icing tastes good!

So what happens now?  Well, that is what the experimental teams are discussing, but essentially we’ll keep refining our own operational procedures using cosmic rays, take the opportunity to shore up the weak links in our systems, like fans that are affected by the magnetic fields, or failing electronic components, etc – turns out even the elevator at CMS is somewhat susceptible to the stray magnetic field – there are stairs for backup, but it is a long way up.

I hope (and expect) we’ll get a debriefing on what went wrong in the accelerator, and why it wasn’t caught in testing before the turn on, but right now they have to wait until the arcs are warm before they can go find out.  Anyway, one of the most remarkable things we’ve learned so far is that people are genuinely excited about what is happening, which enourmously gratifying – keep asking questions, we’ll keep answering, and try to fill you in on what to expect in the next few months.


Can’t get it out of my head

Wednesday, September 10th, 2008

Well, I thought of a song to promote science education and the LHC, particularly appropriate today – if Katie can do it, so can I! Although my demographic is definitely different than hers. Have a listen.

Some comments

  • Who says scientists cannot be completely ridiculous
  • I believe I should put off that career in music and stick with my day job
  • I attempted to get a more friendly performer, but was refused – although it might cost him some allowance
  • There was some breakfast table discussion about what detrimental effects this may have on my career, but if you don’t take risks, you’ll never really live, right?

Anyway, the real problem is that I cannot get the song out of my head.  Feel free to add more verses, I can really see the target audience getting into “Crash Crash Crash…”


The race is on, but it is a marathon

Wednesday, September 10th, 2008

In fact, it happened like I might have expected.  There was a small bit of excitement when one of the many turbines around the ring failed last night, and had to be quickly repaired before injections could occur.  A little bump in the road, overcome fairly quickly, and success in the end, somewhat delayed.

While I am caught up in the excitement of it all, I do have to keep reminding myself that this is a marathon, not a 100m dash.  It is excellent to have concrete evidence that the LHC will provide us with a new window on the subatomic world, but it will take us months or years to open that window and fully appreciate the view.   We have guesses about what might be behind the window, but are hoping to find something unexpected.

Oops, mixed metaphors.  Oh well, that’s what you get with spontaneous writing.  Anyway, it is good to see the events from beam remnants, good to see that the beam monitors are verifying the beam going around the ring multiple times, and good that the world is watching.  But we’re still in the first steps of the marathon, where everyone is sort of walk-running and bumping into things and each other- We have a ways to go before we hit our stride.


Curved Tracks

Wednesday, September 3rd, 2008

They did get to 3 Tesla the other evening, and after a long set of safety checks making sure the residual magnetic field (100 mT~ 100 Gauss, still 100x the Earth’s field!) near the cooling and power supply racks didn’t affect their performance, they turned on the tracker and took some data – only about 5 minutes worth, as it was 2 AM on a Sunday morning, so you cannot really fault them for that, since they’d been at it all Saturday.   In that 5 minutes we saw curved tracks:First curved tracks duing a trial run at 3T

You are looking at a schematic of our tracker end on – each concentric layer is made of many silicon wafers, and we have ten layers in the barrel region (6 outer layer in magenta, plus 4 in blue, and lest I draw the wrath of Freya the pixel detector is also part of the tracker and is the three innermost layers in green, so I guess we really have 13). The red line is a projection of the path of a muon, which left energy depositions in the layers at the little red points.  This one just happened to graze our detector (remember – we aren’t built to measure Cosmic Rays, but really the tracks from the interaction point) but it is easy to see the curvature, which is of paramount importance to measuring the track energy.

The magnet tests went well, apparently the biggest trouble they had was that the elevator seems to be susceptible to high magnetic fields, so the fire brigade had to extract someone.  Well, if I have to, I’ll take the stairs!