Dr. Kimberly Palladino

Abstract:

We report new limits on cosmic neutrino fluxes from the test flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day flight of a prototype long-duration balloon payload, called ANITA-lite, in early 2004. We search for impulsive events that could be associated with ultrahigh energy neutrino interactions in the ice and derive limits that constrain several models for ultrahigh energy neutrino fluxes and rule out the long-standing -burst model.

Abstract:

• ANITA project has been progressing in amazing pace • instrument is well tested, understood, and calibrated with SLAC electron beam • ANITA is now ready to detect UHE neutrinos - collaborators heading for Antarctica - two calibration radio sources scheduled to be set up. • a nominal 15 days flight should cut into expected GZK flux • hope to have a longer flight (like 42 days CREAM '0405 flight) and a positive detection of GZK neutrinos.

Abstract:

The Antarctic Impulsive Transient Antenna (ANITA) experiment is being developed to search for ultra-high-energy (UHE) neutrino interactions ($>3\times10^{18}$ eV) in the Antarctic ice cap. A neutrino interaction in the ice will produce a radio pulse by the means of the Askaryan effect. The large radio transparency of ice allows for such a pulse to be recorded by a cluster of balloon-borne antennas. The details of the ANITA instrument, now in a construction phase, and the science we hope to achieve is discussed. In order to prepare for the main mission, we have flown ANITA-lite during the 2003/04 austral season. ANITA-lite consisted of two quad-ridge horn antennas and a prototype RF (radio frequency) triggering and recording system. Here we present the results of an impulsive RF background survey of Antarctica, as well as proof-of-principle gain, tracking, and timing calibrations conducted by observing solar radio emissions and calibration radio-pulses. A preliminary UHE neutrino flux limit based on ANITA-lite data is also presented.

Abstract:

The ANITA experiment is a balloon-borne radio-pulse detector system designed to measure Ultra-High Energy (UHE) neutrinos interacting in the Antarctic ice utilizing the distinct broadband radio pulse due to the Askaryan effect. The radio-transparent ice serves as a target volume for the production of these pulses. ANITA will have an effective viewing area of over one million km2 of ice at float altitude (∼37 km). A prototype experiment, ANITA-LITE, was flown during the 2003-2004 Austral Summer from Antarctica to perform an impulsive RF background survey of Antarctica. In the process, it has yielded strong constraints on UHE neutrinos, ruling out some theoretical models. We also discuss the expected instrument performance for the first full ANITA flight, planned for a 2006 Austral Summer launch out of McMurdo, Antarctica.