ANITA Launch
In response to a friend's request, here finally is that post about neutrinos. Cosmic Rays are a big source of concern. Last week the crews of ISS and Discovery had to take shelter because of solar flares. Isn't that how the Fantastic Four got started? Sometimes the best science happens outside the glare of publicity. I was privileged to talk with NASA Administrator Michael Griffin at last year's AGU Meeting, and have met with other NASA officials since then.
Friday December 15 a very exciting experiment was launched from McMurdo Sound. That is Mount Erebus in the background. The Antarctic Impulsive Transient Antenna (ANITA) is a low-cost balloon experiment searching for the highest energy neutrinos from Space. The detector was tested this June at SLAC in sunny California using a ten-ton block of ice. See the live mission clock and other links here!
Because University of Hawaii is the lead institution, a hula girl paint scheme was chosen. Panel to the right says in Hawaiian: "The Stars Are the Spies of Heaven."
From the ANITA Project Website: "Why study neutrinos? Neutrinos are of great interest to astrophysicists as they are the only particle that can reach Earth unattenuated at all energies. This is particularly of interest at high energies where other particles and photons will interact with the photons of the microwave background making them unable to propagate and survive over long astrophysical distances.
"The ANITA instrument detects these ultra-high energy neutrinos by use of the Askaryan effect. This effect predicts the production of a coherent radio emission from the cascade of particles produced in a high-energy particle interaction. In other words, we're detecting a 'snap' in the radio frequencies caused by the interaction of our ultra-high energy neutrino.
"In order to detect this radio emission (Askaryan pulses) we need a radio transparent medium for the interaction to occur in - and lots of interactions are rare. Some materiels that are radio transparent are salt, sand and ice. We also need a fairly quiet radio area as the Askaryan pulses are very faint signals.
"The ANITA instrument is designed to fly over the continent of Antarctica - the location of the most pure ice in the world and one of the most radio quiet spots on Earth. Flying at 120,000 ft the instrument can observe ~ 1.5 million square kilkometers of ice. Even with a detector area that large we don't expect to see more than a hundred or so events (and possibly much fewer).
Relating to a previous question, detecting very high-energy neutrinos would be yet another indicator of a higher primordial speed of light. Here is the launch December 15, 1340 New Zealand Daylight Time. Go, baby, go!!
4 Comments:
Ooooh, exciting. Thanks for the photographs. We have a team at UC working on the RICE experiment down on the ice. Good stuff.
Our super GZK capabilities will improve greatly in the next few years, which should sort out GZK one way or another. See for example this. Could you show us quantitatively why you expect the UHE neutrinos?
Working on that, thanks. Lots of excitment about global warming this week.
12 19 06
Hello Louise:
Thanks:) and Merry Christmas to you and your loved ones.
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