Accelerator Measurments of the Askaryan Effect in Rock Salt: A Roadmap Toward Teraton Underground Neutrino Detectors

Technical Report · Wed Dec 15 04:00:00 EST 2004

DOI:https://doi.org/10.2172/839783· OSTI ID:839783

Gorham, P ^[1]

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1. SLAC

We report on further SLAC measurements of the Askaryan effect: coherent radio emission from charge asymmetry in electromagnetic cascades. We used synthetic rock salt as the dielectric medium, with cascades produced by GeV bremsstrahlung photons at the Final Focus Test Beam. We extend our prior discovery measurements to a wider range of parameter space and explore the effect in a dielectric medium of great potential interest to large scale ultra-high energy neutrino detectors: rock salt (halite), which occurs naturally in high purity formations containing in many cases hundreds of cubic km of water-equivalent mass. We observed strong coherent pulsed radio emission over a frequency band from 0.2-15 GHz. A grid of embedded dual-polarization antennas was used to confirm the high degree of linear polarization and track the change of direction of the electric-field vector with azimuth around the shower. Coherence was observed over 4 orders of magnitude of shower energy. The frequency dependence of the radiation was tested over two orders of magnitude of UHF and microwave frequencies. We have also made the first observations of coherent transition radiation from the Askaryan charge excess, and the result agrees well with theoretical predictions. Based on these results we have performed detailed and conservative simulation of a realistic GZK neutrino telescope array within a salt-dome, and we find it capable of detecting 10 or more contained events per year from even the most conservative GZK neutrino models.

• Research Organization: Stanford Linear Accelerator Center (SLAC), Menlo Park, CA
• Sponsoring Organization: SC
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 839783
• Report Number(s): SLAC-PUB-10912
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
ACCELERATORS
ASYMMETRY
BREMSSTRAHLUNG
DIELECTRIC MATERIALS
FREQUENCY DEPENDENCE
HALITE
NEUTRINOS
PHOTONS
POLARIZATION
RADIATIONS
SALT DEPOSITS
SIMULATION
SYNTHETIC ROCKS
TRANSITION RADIATION
VECTORS