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Archive for February, 2008

Tower of Babel

Wednesday, February 27th, 2008

I am trying to think of a word that adequately describes my ability to learn languages. Abysmal, for example. That would be a good description. Actually even my English can be quite ‘creative’ at times. So much so, it once led my advisor, Gene, to ask, ‘Are you sure that English is your native language?’. Thus, my personal inability to learn languages makes me envy and admire many of my colleagues who have no problem conversing in whatever language necessary.

When it comes to communication, English is certainly this field’s lingua franca. Talks at conferences, meetings, analysis papers for example are all in English. But at CERN, native English speaks are a minority. So it is not uncommon to be in a meeting (in English) and yet be the only native speaker. Nor is it uncommon to be speaking with someone whose English is very, very good, essentially perfect and then learn that this person has never actually been to an English-speaking country. That they have learned English in the presence of non-native speakers.

One hears complaints that the English spoken here has become ‘twisted’. In the sense that it has become its own dialect. We have of course both American and British dialects, but now maybe we have a generic non-native dialect which is something of a melting pot of the 100 or so languages spoken here at CERN. I for one rather like it. It is interesting to see how the Greeks will phrase a sentence, compared to the Italians or Russians or Chinese. It is a little glimpse into their own language through the English.

Although English is generally the one language nearly everyone uses, it is interesting to see this web of communication that people create. Most of my European colleagues, for example, tend to speak three languages: their native language, English and then a third. It is very common therefore to have two people who not only both speak English but also both speak German. And why speak only English, when you can speak both? Some things are better said in one language then another. And I often see people switching from one language to the next where it best fits the conversation. The two languages are simply combined. And why not: isn’t two always better than one?

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Atlas’ Globe

Friday, February 22nd, 2008

And for those curious what I actually want to do with ATLAS, here’s one hint (a somwhat detailed, but not exhaustive, summary). This is a link to the talk I gave in Jaipur, India a couple of weeks ago. It (briefly, almost cryptically) motivates the utility of “Global observables” in the study of heavy ion collisions, as well as the so-called “minimum-bias” proton-proton collisions we’ll soon be getting at the LHC, and ATLAS. While these observables — counting the number of particles, or measuring the amount of energy dumped into the collisions — sound “simple” on one hand (at least to measure), they are surprisingly resistant to ab initio calculations using the usual perturbative methods common in particle physics. Even weirder, they show surprising commonalities between different collision systems (nucleus-nucleus, proton-proton, even electron-positron), which can lead one (OK, me) in some interesting conceptual directions if you’re willing to follow your nose a bit. More on this later, if anyone’s interested (as if you need to ask!).

And just in case anyone didn’t notice the image, that’s the real ATLAS logo, Lee Lawrie’s status of ATLAS, which has been sitting in front of Rockefeller Center since the Great Depression. One comes up with these things working on talks late into the night sometimes.

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Small Wheels Descend

Tuesday, February 19th, 2008

I fully and completely admit that I am a total sucker for heavy machinery. It is something I have in common with most four-year-olds. Take us to a construction site, feed us peanut butter and jelly sandwiches and we will be happy all day.

On that note, I couldn’t resist showing some pictures of the ‘small wheels’ being lowered. The small wheels are part of the Muon system. They are located between the end of the calorimeter and the toroid magnet end-caps. And they are the last big piece of the detector to be installed.

As the small wheels were assembled on surface, the first order of business is transporting the wheels to the ATLAS surface building. Fortunately CERN has many custom trucks for this kind of transport. Seen here one of the wheels is moved (very slowly) into the surface building on this massive, two-lane wide flat-bed truck. And this truck is just one of many in CERN’s armada of very cool transportation vehicles. These vehicles do contribute to frustrating local drivers, though. It is one of the interesting ‘features’ of the area. It is not uncommon, for example, to get stuck behind either some slow-moving tractor carrying hay or some slow-moving truck carrying a huge super-conducting dipole magnet.

Moving the Small Wheel

From the surface building, the wheel is lowered by the crane down one of the access shafts to the ATLAS cavern. In the picture, one small wheel is attached to the crane and suspended over the access shaft, while the second (in the foreground) waits its turn.

Small wheels at surface

So why do we call them small wheels? In this picture as the small wheel is lowered into the cavern, you can see one of its siblings, the ‘Big Wheel’ on the right. Small really is just relative.

small and big wheels

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Not ready for remote operation

Friday, February 15th, 2008

One of the more interesting aspects of working on this experiment is the emphasis on remote operations. For both of my previous experiments (I started on CMS in 2000), this meant that you used your office or home computer (with modem) to connect and opened a terminal window to a specific computer connected to the data acquisition system of the experiment (my old 386 even made the text green and the background black – just like at work). It was pretty primitive, but I remember checking and helping with problems and not having to go into the experiment, which for my first experiment meant a 90 minute drive from home.

For this experiment, it is much more sophisticated. We have a Remote Operations Center (ROC) at Fermi National Accelerator Laboratory (FNAL), all the way across the ocean near Chicago. We also have a control room located at the main CERN site, and one upstairs from where we currently sit, which isn’t quite ready for prime time (it’s lacking vital things, like computers, and a coffee machine). These do/will have fast internet connections, computers, printers, and the like.

But, when we are downstairs, such as during this past week, we were trying to keep things going with some colleagues by phone, which proved difficult. I was playing secretary and answering the fixed phone, and things were only slowly moving forward. People were becoming frustrated. At this point in the commissioning of the experiment, it really helps to be in the same room with the experts involved. The communication channels are always open since they are just a shout away. (Unless one expert is on the phone remotely with someone else, which is unavoidable, since we _almost_ all have mobile phones.) Things are still a bit unstable and unpredictable as we commission the system. Soon it will get better, but it is still a lot of “two steps forward, one step back”.

Here were are – all experts underground:

CMS Underground Control Room

And I’ve been down here too much this week, and I’m getting bleary-eyed and I am ready to spend some time above ground this weekend – I think my vitamin D stores are low…

A la prochain…

postscript to the previous post: Evie had a little improvement, and we brought her home for a couple of days, but again she deteriorated. We made the tough decision to put her to sleep on Monday, Feb. 4, she was 7. We miss her, of course, but couldn’t watch her suffer anymore. She was a loving, affectionate, fun cat, and we are glad to have been on her staff: “Dogs have owners, cats have staff.” – Unknown

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Ends of the Earth

Friday, February 15th, 2008

Whew, it’s been a busy couple of weeks moving between what feel like two ends of the Earth: a week in Jaipur, India attending Quark Matter 2008, the “big” conference in Heavy Ion Physics (where I’m coming from), and a week at CERN (from where I write) at ATLAS week. Not that I didn’t consider blogging during these hectic days, but as I’ve mentioned before: Life + Blogging = const, and although it looks like we’re doing nothing but sitting around in meetings, talks, etc. all the day long, we’re also doing lots of important things in the quiet, like reading the Times and writing emails. OK, we’re also learning, plotting, strategizing, thinking — and listening. It’s really that pesky listening thing that gets in the way of constant, or even occasional, blogging.

Anyway so here we are, wrapping up two intense meetings (and getting ready for a couple of well-earned days in the Swiss Alps). Quark Matter was a nice time, even if I showed up 3 days late (only 2 of them by design, the third due to a fog bank in Delhi on Wednesday morning, and a little “mix-up” about my hotel reservation in Jaipur). Lots of interesting, if disparate, results and some excellent wandering around Jaipur and environs, and a fantastic banquet. For some record of this, have a look at my Flickr set. There are conference shots, Jaipur shots, and a lot of stuff taken by me hanging out the bus window.

ATLAS week was hectic as usual, with the usual 9-6 meeting schedule (plenaries, parallels, and impromptu). Things are really heating up here, something which I probably perceive more dramatically than my other colleagues on this blog since I have been at CERN so infrequently recently (something which should be changing, I hope!) The CERN cafeteria is simply buzzing these days, at all hours, with orders of magnitude more young physicsts than I ever saw in my old days here as a student. And it really seems like TV crews are crawling the place, although I only see them following people around as they eat lunch, which I hope isn’t the bulk of the footage. Anticipations — and tensions — are running high, mainly for the p+p program (the heart of the matter) and also for the heavy ion program, which is progressing more and more rapidly by the week.

Anyway, back to the listening thing. I should get to my Quark Matter rundown (especially the various LHC showdowns) soon.

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ATLAS Real Language

Tuesday, February 12th, 2008

The main language within ATLAS is not English or French or Italian. It is the language of acronyms. Ask any new person what the most difficult thing about ATLAS is and they will say understanding what people are saying. Oh yes, they can understand all the words and syllables but not the encoded meaning of the acronyms.

The number of acronyms is a little out of control. We have webpages devoted to our acronym definitions. ATLAS itself is a bit of a kluge of an acronym.

ATLAS: A Toroidal LHC ApparatuS

I think this is a great example of deciding on the acronym first and then settling on the meaning.

Additionally with so many acronyms, you end up having acronyms that are phonetically the same. Such as

DAQ: Data Acquisition System
DAC: Digital to Analog Converter

This leads to conversations like

Person one: I am trying to measure the exact setting of the DAC
Person two: But we know what value the DAQ is setting. It is written out to the log file.
Person one: What are you talking about?
Person two: What are you talking about?
Person one: The DAC setting. D-A-C!
Person two: Oh. Right.

And then it is inevitable that you get to acronyms of acronyms. Like

RCD: ROD Crate DAQ

which fully stands for Read-Out Driver Crate Data Acquisition System

And then there are acronyms like this….

OTSMOU (pronounced Ots-moo) meaning the Operation Task Sharing and Maintenance and Operation Update.

This is my personal favorite acronym of all time. This acronym is genius for so many reasons. a) Seeing the full meaning of the acronym offers the reader zero insight about what exactly this is. ‘Maintenance and Operation Update’? Is that a group of people or a software package? It is unclear. b) The word ‘Operation’ is used twice. c) The acronym just exudes management. It is difficult to create an acronym that once spoken instantly conveys the image of management to the listener. Yet, this acronym accomplishes just that. And d) the person inventing this name clearly must still be laughing.

My only comfort is that if people (management excepted) continue to stick to the TLA (Three Letter Acronym) rule, we will eventually run out of combinations.

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She did her part, did you do yours?

Wednesday, February 6th, 2008

I’m so proud. I told you my Mom was on the job. She’s waiting to hear back from her representatives. By the way, the proposed budget for 2009 just put out looks better (but we’ve been down this road before).

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Down and Up Again

Tuesday, February 5th, 2008

The looming nature of ‘the closing’ has injected an increased sense of urgency into all those still working on detector installation. Since TileCal has been installed in the pit for several years now, you would think we would be exempt from such urgency. But no. In the past year or so, TileCal has undergone a campaign to repair some less-than-optimal components in our electronics. The front-end electronics for the TileCal are organized in long ‘drawers’ which can be pulled out from the ends of the calorimeter. We are replacing things like the power connectors which have been causing some problems over time. In the past year, we had the time and detector access to make these repairs so we decided not to wait for the problems to worsen.

There are 256 electronics drawers in TileCal so upgrading every single one is more than a day’s work. The drawer itself is almost nine feet long. It has to be removed from the calorimeter, lowered down to the floor of the detector cavern. On the floor, three electronics tables are set up where technicians can make the modifications. Once done, the drawer is tested, raised back to the calorimeter, re-inserted and re-tested.

One of the most difficult parts of this procedure is just getting the drawer from the calorimeter to the technician’s tables. There is no space to make the modifications right at the calorimeter so moving the drawer is the only solution. Furthermore, the scaffolding surrounding the calorimeter is accessible by ladders so we have to invent some creative ways to get the electronics drawers up and down the scaffolding.

One technique is to lower and raise the drawers through the access areas in the scaffolding. As seen here. The blue boxes at the top of the picture is the part of the calorimeter, where the electronic drawers are inserted. In the center of the picture, part of one of the drawers is being raised between two access ladders. This is delicate work. You don’t want to go banging your newly repaired electronic drawer against the sides of the scaffolding. And these are all custom-built electronics. It is not like you can go get a replacement at Radio Shack. On my former experiment, SNO, the electronics racks had signs reading, ‘Careful! These electronics cost more than your house!’.

raising a drawer

It is times like these where I really admire a technician’s patience. The pressure of ‘the closing’ is increasing, everyone knows that soon the scaffolding will come down, the collective heart rate has gone up several beats. But the technicians are never fazed and continue to raise the drawers with the same patience and precision as ever. They know better than anyone: you raise the drawer too fast, you will break it. We are in good hands with those guys.

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A Love-Hate Relationship

Friday, February 1st, 2008

Without the internet, it would be impossible to do my job. We rely on it to control our hardware: we have several special boxes that have their own internet addresses in our CMS private network. We can talk to it via the internet to control the power in our racks, readout the temperature of the crates (cold? go stand next to a powered RCT crate for awhile) and other things about our racks. Its great, because to turn off or on crate power and I don’t have to be in the same room. I can also log in remotely and configure all my crates with special software, using a package we call the “Trigger Supervisor” to write to the memories on our boards and read out bits that tell us the status of various parts of it. This makes use of a browser like Firefox or Safari (I’m an Apple fan), and can be done anywhere in the world (in principle – though sometimes it is too slow).

We also use it to keep in touch via e-mail and video conferencing, document our hardware, and research topics. Because of all this, and because I am living abroad, far from my family, I have access at home as well. I have wireless so that I can sit in any room of my small apartment and work, talk with my family via Skype, shop, or just goof off and surf the web. I love this technology for all it enables me to do.

But it sometimes seems to rule my life – my home computer is beeping at me whenever an e-mail comes in – demanding my attention. If I happen to read an email before I go to bed that agitates me in some way, I can’t go to sleep until I answer it. For complete peace, I have to put my computer to sleep too. Sometimes I don’t want to talk to anyone via Skype, so I have to shut that program down, and the mail program has to be shut down too. There are times when the spam is out of hand, and I hate it for all that.

JungleCat

But it was recently able to give me some answers and some peace of mind. My littlest cat, who has even had her picture in one my posts (Evie: see above), has developed a very rare condition of the nervous system, dysautonomia. This condition leaves her digestive system unresponsive because the contractions which are automatic don’t work anymore. Because of the internet, I was able to find out that there is no treatment, other than symptom relief, and it is fatal. This sounds awful, I know, but it allows me to be able to let go, as hard as it is, and not be angry with the vets for not doing enough when they care for her. We are trying something experimental to see if it helps, for the next few days, but don’t want to see her suffer, so at some point we will have to say it is time for her to go.
A la prochain…

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