19 October 2012 Intro to the Expedition

My expedition dates are getting close! I thought this would be a good time to do a more thorough introduction to the project I’ll be helping with.

IceCube

The IceCube NeutrinoAn elementary particle with zero charge and zero mass. An electrically neutral particle that is often emitted in the process of radioactive decay of nuclei. Neutrinos are difficult to detect, and their existence was postulated twenty years before the first one was actually discovered in the laboratory. Millions of neutrinos produced by nuclear reactions in the sun pass through your body every second without disturbing any atoms. ObservatoryA location used for observing terrestrial and/or celestial events. is basically a giant telescope buried under the ice at the South Pole. Unlike other telescopes, it’s not looking for light from stars. It’s trying to detect light given off by little particles called muons. But, muons aren’t really the goal. Muons are interesting because some of them are created by other tiny little particles called neutrinos. For a great introduction to neutrinos, I highly recommend watching this video (made by Casey O’Hara, another PolarTREC teacher who worked with IceCube in 2009):

http://youtu.be/aMnGWqoDaAA

Askaryan Effect

So, neutrinos can make muons and muons produce a small flash of blue light (Cherenkov radiation – this is the same reason that uranium glows blue in water).

But there’s another cool way to detect neutrinos!

In the 1960’s, a physicist named Gurgen Askaryan came up with the idea that, if a particle (like the quickly moving neutrino) travels through a material at the right speed, it can create a cloud of charged particles behind it. These charged particles are arranged in such a way that they actually create a burst of radio waves! So, if we have radio antennas, we could pick up those waves and then we know there was a neutrino. This is the catch: the material can only be a few different things like salt, moon dust, or… (drum roll, please)… ice!

How cool is that? There’s already a project at the South Pole for detecting neutrinos and now, here’s this second way to detect them that also uses ice. Serendipitous.

The Askaryan Radio Array (ARA)

So, to detect the radio waves, we need a radio antenna. The problem is, if we only have one antenna, we don’t get a lot of information about what direction the neutrinos came from or how much energy the neutrinos have. To solve this problem, there are several antennas being placed in the ice in an array. Right now, the array is still in the early phases of construction.

I’m technically part of the IceCube crew but I’ll be helping with ARA, doing whatever they need me to do.