Tuesday, April 1, 2008


There's a famous story amongst physicists about Robert Wilson, the first director of Fermilab who played a huge role in the development and construction of the facility. Once, when pressed by a US Senator on whether Fermilab would do for national security, Wilson retorted by saying "it has nothing to do with the defense of our nation, except to make it worth defending."

I was thinking a lot about this this weekend because our Physics and Astronomy Club got the wonderful opportunity to visit Fermilab, and let the record show that Wilson is absolutely right. It really is a great place, filled with world-class research that is downright exciting to see for yourself!
This is the main building at Fermilab, which was our first stop of the day after waking up really early in the morning to drive the ~6 hours from Cleveland to Batavia, Illinois. We were supposed to meet at 6 but I didn't wake up until my friend called me at 6:25 asking where I was, which prompted a loud "why the [censored] did my alarm not go off?!?" followed by frantic scurrying out the door. Our car was actually on the road by 6:35 though, so no problem getting there (and I confess I don't remember much of the drive, as I spent most of it napping in the back seat there and back).

But anyway, if you ever go and tour Fermilab you'll probably be taken to the top story of the building above, which is a museum of sorts for the facility and has a great view-

This picture is looking out from the main enterance. Don't be fooled by the decorative-looking ponds, they're actually there to drain in case the giant Tevatron accelerator's superconducting magnets stop doing their job correctly.... Fermilab for the most part doesn't look that impressive from above for the simple reason that most particle experiments are done underground, but they've creatively made up for this by making the place the biggest restorative prairie in the state of Illinois. There's even a herd of buffalo wandering around the place.
This is another view from the 15th story, this one looking towards part of the Tevatron (the entire ring is four miles in circumference or so, so I couldn't even begin to see all of it, let alone get a decent picture). Essentially the point of the Tevatron is to speed up ionized hydrogen gas so it travels just a tiny fraction under the speed of light, then smash together the particles and see what we see. It's sort of like if you had a clock and smashed it to have all the parts fly apart and tried to reassemble the clock based on what you find. Doesn't sound very effective in a sense, but this is really what particle physicists do except for atoms and for Fermilab this proved to be quite effective- the top quark and bottom quark were discovered here.
We couldn't go into the Tevatron itself but there was a mockup with mirrors so you could step in and sort of get a feel for what it's like. Currently the Tevatron is the most powerful operational particle accelerator in the world until the Large Hadron Collider turns on later this year, after which the Tevatron will be shut down (as the LHC will be several times more powerful). We also learned that the Tevatron gets an electric bill of approximately a million dollars a month, making me conclude that the local electric company really hit the jackpot when Batavia won the rights to build it.
We did get to take a look at the control room for the Tevatron, which is pictured above. I must say the operators had a great sense of humor about it- there's a large glass panel all the tours stop at, so they put up a "do not feed the operators" sign on the door for good measure. Further, at one point one of the operators abruptly turned us and snapped a picture of us with his own camera as retaliation for all the ones we were taking, and I thought that was hilarious.

We also checked out one of the smaller experiments on site, known as MiniBooNE. This one tests for neutrino mass via neutrino oscillations, and they specially built a tunnel 300 feet below ground to do it (so ~30 stories). It's a pretty long elevator ride!
Here's what the tunnel looked like underground. I think I prefer looking at the sky.
This large box is part of an experiment in the tunnel trying to find dark matter. Basically there's a bit of water inside and a particle passing through leaves a bubble trail, so you're looking for a bubble trail that would be left over from a dark matter candidate... Of course, you get noise from things like cosmic rays that find their way in even down here and radioactive decay from the glass holding the water and all sorts of things most people would never think of, so no dark matter yet. You can hear the machine go "ping" once a minute or so thanks to all the false positives.

And this is in no way a critical judgment against my friends who are dedicating their lives to the dark matter search, but I decided within five minutes this is not exactly my sort of project. This is, of course, the amount of time the novelty of being 30 stories underground wears off on you, and don't know if I could spend years obsessing over if my glass is radioactive and what not. Different strokes for different folks...
This is the origin of the neutrinos in miniBooNE, which are generated here on the order of a billion neutrinos pulsed every 2.5 seconds (so standing in front of it means you're in the most concentrated beam of neutrinos on the planet- luckily they pass right through you harmlessly!). The neutrinos then tunnel underground to another detector in a mine in Soudan, Minnesota several hundred miles away- leading physicists to joke that they're using Wisconsin as a drift space- and they vary the type of neutrinos produced so they can see if there are any differences between the pulses upon detection.

Explaining how exactly you make a neutrino beam takes a fair amount of time and I don't want to make this much longer than it already is/ will be, so if you're interested take a gander over here.
Finally, our group underground (there were actually 20 or so students on this trip, but only so many of us could be underground at a given time). Now that I look at this picture, all I can say is I'm the one who really stands out compared to all the dark colors everyone else was apparently wearing!

As one last entertaining postscript, we went to the visitor center while waiting for the last group to finish touring, which is filled with cute little science displays you usually find at science centers to entertain little kids. Needless to say we had a blast, but I was particularly enamored with this one-
I really can't pretend to know why it was there, but in short it's a scintillator panel cosmic ray detector, which is something I'm using in my own senior project setup! So if I don't get mine to work, think they'll let me hang out in the Fermilab visitor center and collect data?

But anyway, that was the end of our time at Fermilab as we were off to a swanky restaurant to hang out with some members of the Case Alumni Association who were kind enough to foot our trip bill. I spent a lot of time talking to Cyrus Taylor, Dean of the College of Arts and Sciences and speaker for the night, and we spent a great deal of time discussing things like women in science, string theory, and Dean Taylor's crazy backpacking trip through Tanzania after he got his PhD which involved an economic meltdown and him getting sick with malaria for three weeks. You know, normal physicist talk!

And last but not least we were all exhausted having gotten up so early, so we went back to the hotel to crash. Because after all there was a big day ahead of us, with the city of Chicago looming nearby...