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I worked in the Cosmic Ray Research group at Utah as an undergrad and postgrad. I started at the tail end of HiRes, which was the sucessor to Fly's Eye, and hel
by batbomb 11y ago
I worked in the Cosmic Ray Research group at Utah as an undergrad and postgrad. I started at the tail end of HiRes, which was the sucessor to Fly's Eye, and helped develop, test, deploy, run etc... parts of the Telescope Array experiment.
I know a bunch about these experiments if anybody is curious.
Also, AFAIK, Telescope Array has the only approved outdoor LINAC^H^H^H^H^H "electron light source" they fire directly into the sky. We joked about it giving birds cancer. It's also a potentially an awesome lightning rod.
- Trombone12 11y agoIs there a chance of seeing these showers by eye, or are they too weak even for the extremely high events compared to the stars?
- batbomb 11y agoYou can't see them by eye, we detect indirectly through nitrogen fluorescence with Photomultiplier tubes and mirrors, and for Telescope Array, also with scintillation detectors. That being said, there are EAS everywhere.
- Trombone12 11y agoHow does this really work? I imagine looking at the starry sky for brief flashes of light is not without complications, what are the biggest backgrounds?
- batbomb 11y agoTo elaborate, when a proton (or iron) particle hits the atmosphere, it starts interacting with matter it hasn't interacted with before. These interactions produce pions and kaons, which decays further until you end up with a bunch of electrons/positrons, gamma rays, and muons. These particles ionize the atmosphere, which puts the electrons in the N2 orbitals in a frenzy, causing fluorescence and Cerenkov radiation (also light). This light is more energetic (shorter wavelength, more blue, near-UV, etc...) than the human eye can detect. In theory you could maybe see some light (in high humidity environments, but I think there's a bunch of favorable conditions that would be required for that to happen.
- ridgeguy 11y agoI was very curious about "the only approved outdoor LINAC...". I presume it's what this article describes? http://galprop.stanford.edu/elibrary/icrc/2011/papers/HE1.4/icrc1252.pdf http://galprop.stanford.edu/elibrary/icrc/2011/papers/HE1.4/...
- batbomb 11y agoYep, that's it. We used to calibrate with laser shots into the night sky, but direct excitation of the sky with the LINAC is much better, because you are directly measuring fluorescence.