| アブストラクト: |
The primary objective of the ANtarctic Impulsive Transient Antenna
(ANITA) mission is to investigate and constrain the nature of the
sources of high energy cosmic ray particles above 100 EeV, by
measurements of neutrinos that are strongly believed to be both
spectrally and spatially correlated to them. Observation over the
last 40 years of several dozen cosmic ray events with energies
exceeding the Greisen-Zatsepin-Kuzmin (GZK) cutoff poses among the
most intriguing and intractable problems in high energy astrophysics.
Operating from a long-duration balloon at an altitude of 37km, ANITA
will synoptically observe the Antarctic ice sheet out to a horizon of
more than 600km, giving a detection volume of order 1 million cubic
kilometers. ANITA will search for radio pulses that arise from
electromagnetic cascade interactions of high energy neurinos within
the ice. Such radio pulses, recently confirmed in accelerator
experiments, easily propagate through the ice due to its remarkable
radio transparency. During the 2003-2004 Austral Summer a prototype
of the ANITA payload, designated ANITA-lite, was flown on an Antarctic
long-duration balloon flight and validated the experimental technique.
Essential to the viabiliy of a full-size instrument, low-power radio
frequency instrumentation has been developed and results of this
successful R&D program will be presented. Time permitting,
application of this Askaryan-effect detection technique to naturally
occuring salt domes, and results from a detector prototype, will be
provided. |
