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Posts Tagged ‘switching experiments’

More Multitasking

Friday, April 13th, 2012

I fell out of practice at multitasking at the end of grad school. For the final six months, almost all of my work went into finalizing how to present my analysis results. There were two versions of the presentation: the paper and my thesis, but the general direction of work was all the same. The previous tasks I had worked on, geared toward keeping ATLAS running, were all long since “done,” at least as far as I was concerned.

Starting a postdoc means a sudden change of gears, with more multitasking than ever before. I’ve started many new projects from scratch at the same time, and because I’m new to CMS, every one of those tasks involves tools and procedures that I don’t know. It’s easy to lose track of some of those tasks at any given time, or simply to want to focus on one thing until I understand it, but the job doesn’t work that way. Being succesful as a postdoc will mean significant contributions to the running and understanding of the detector and significant contributions to keeping my group’s analysis running and starting a new analysis (sub)channel of my own. None can be dropped, and most of the things I’m doing have deadlines in the next few months.

So I’m having to remember and improve my multitasking skills, quickly. Step one is bringing this post to a close, and asking you to wish me luck, and getting back to work!


Location, Location, Location

Thursday, January 19th, 2012

If I had to pick one thing that’s definitely better on my old experiment, ATLAS, than on my new experiment, CMS — and especially if I had to pick something I could write publicly without getting into trouble — it would be this: the ATLAS detector is across the street from the rest of CERN. I’m not sure how that was decided, but once you know that, you know where CMS has to be: on the other side of the ring, 5 or 6 miles away. That’s because the detectors have the same goals and need the same beam conditions; two opposite points on the LHC are where a duplicate performance is easiest. The pre-existing caverns from the LEP collider, whose tunnel the LHC now uses, probably also helped determine where the detectors are.

In any case, it used to be that when I wanted to work on my detector, I had only to go across the street. Now I have to drive out of Switzerland and several miles into France. Except, I don’t like driving. So I’ve been working on alternate means of transportation. A few months ago I walked. Last night I had to go to downtown Geneva, so I took the bus. It’s actually pretty good, although the bus stop is a mile away from CMS. There’s also the shift shuttle, which runs from the main CERN site to CMS every 8 hours via a rather roundabout route. And I can bike, once the weather gets better and I get myself a little more road-worthy. To be honest, every option for getting here is much slower than driving, but I enjoy figuring out ways to get places enough that I’m going to keep trying for a while.

I have plenty of chances to try, because I’ll be here in the CMS control room a lot of the time over the next few weeks. Right now, I’m learning and helping with the pixel detector calibration effort. (We’re changing the operating temperature, so all the settings have to be checked.) Soon I’ll be learning to take on-call shifts. So the more I stay here, the more I learn. I got here this morning, and I won’t leave tonight until about 11 pm. I could take the shift shuttle back — or maybe I’ll just get a ride.


Lost in Acronym Translation

Thursday, October 13th, 2011

My first impression, once I got myself properly into the CMS databases and joined the requisite forty or so mailing lists, was that CMS has a lot more acronyms than I was used to. Particularly jarring were the mysterious PVT (“Physics Validation Team”) meetings, and the many occurrences of “PU” (“pileup“) always looked to me like “Princeton University” until I realized that made no sense in context.

But then I remembered all the acronyms on ATLAS, and learned that “PU” has gotten more common there too now that the increasing pileup is a frequent subject of discussion. (I really wasn’t paying attention generally to either ATLAS or CMS for the year where I did my analysis and wrote my thesis.) So although the culture of acronym use may be a bit different, it’s really just a matter of translating from one experiment’s terms to another.

For example, I recently learned that a JSON (“JavaScript something something”) file indicates which LumiSections (not an acronym, oddly) are good in a set of runs — in other words, for which times are the recorded data for all parts of CMS in good shape? On ATLAS, it would have been a GRL (“good run list”) indicating which LumiBlocks were good.

I still think that acronyms are thrown around in conversation a bit more on CMS than on ATLAS. Fortunately, there is a public list of CMS acronyms to help me. I’m sure I’ll figure them out eventually.


Turning to the Dark Side

Monday, October 3rd, 2011

“So, you’ve turned to the dark side?” I’ve heard it surprisingly often, usually from my new colleagues on CMS. “Yes,” I reply. “My hate makes me powerful.”

We’re just kidding, of course.

I’ve been asked more seriously, on a number of occasions, why I switched from working with ATLAS to working with CMS. There are several ways I can answer that one:

1. Why not? ATLAS and CMS both look for the same exciting things at the LHC: the Higgs boson, supersymmetry, and all sorts of other new physics. They have roughly similar capabilities and, for the most part, conceptually similar designs. So I should be happy to work on either one.

2. It came with the job. Being happy to work on either experiment means I applied to some groups working on ATLAS and some on CMS. The job I ended up with is with Princeton, and they have a CMS group, so…

3. It’s good for our field to exchange techniques and expertise between experiments.

4. It’s good for me to know people from both collaborations and learn different ways of doing things, and good to be forced into doing something completely different than what I did as a graduate student.

So why would switching be a bad idea? Well, mostly, it’s harder. There is more logistics to deal with to get started as a postdoc — on top of the logistics of starting a job — and a lot of time spent learning new software and new organization. And it will take me quite a bit longer to be in a position where I know enough and people have enough confidence in my work to give me significant responsibilities. But all of this, I hope, is transitory.

In the end, neither experiment is the dark side. They do compete with each other — as intended, to keep everyone working hard — but they’re more like opposing sports teams than opposite sides of the Force. You may despise the team across town much of the time, but without them you couldn’t play baseball. And once in a while, players get traded.