arXiv subjects

P. Gorham

Publications and source records attributed to P. Gorham.

8 recordsLinked to original sources

arXiv2022

The SLAC T-510 experiment for radio emission from particle showers: detailed simulation study and interpretation

Over the last several decades, radio detection of air showers has been widely used to detect ultra-high-energy cosmic rays. We developed an experiment under controlled laboratory conditions at SLAC with which we measured the radio-frequency radiation from a charged particle shower produced by bunches of electrons as primaries with known energy. The shower took place in a target made of High Density Polyethylene located in a strong magnetic field. The experiment was designed so that Askaryan and magnetically-induced components of the radio emission could be measured independently. At the same time, we performed a detailed simulation of this experiment to predict the radio signal using two microscopic formalisms, endpoint and ZHS. In this paper, we present the simulation scheme and make a comparison with data characteristics such as linearity with magnetic field and amplitude. The simulations agree with the measurements within uncertainties and present a good description of the data. In particular, reflections within the target that accounted for the largest systematic uncertainties are addressed. The prediction of the amplitude of Askaryan emission agrees with measurements to within 5% for the endpoint formalism and 11% for the ZHS formalism. The amplitudes of magnetically-induced emission agree to within 5% for the endpoint formalism and less than 1% for the ZHS formalism. The agreement of the absolute scale of emission gives confidence in state-of-the-art air shower simulations which are based on the applied formalisms.

astro-ph.IM↗

arXiv2014

Planning the Future of U.S. Particle Physics (Snowmass 2013): Chapter 8: Instrumentation Frontier

These reports present the results of the 2013 Community Summer Study of the APS Division of Particles and Fields ("Snowmass 2013") on the future program of particle physics in the U.S. Chapter 8, on the Instrumentation Frontier, discusses the instrumentation needs of future experiments in the Energy, Intensity, and Cosmic Frontiers, promising new technologies for particle physics research, and issues of gathering resources for long-term research in this area.

hep-ex↗

arXiv2013

An Interferometric Analysis Method for Radio Impulses from Ultra-high Energy Particle Showers

We present an interferometric technique for the reconstruction of ultra-wide band impulsive signals from point sources. This highly sensitive method was developed for the search for ultra-high energy neutrinos with the ANITA experiment but is fully generalizable to any antenna array detecting radio impulsive events. Applications of the interferometric method include event reconstruction, thermal noise and anthropogenic background rejection, and solar imaging for calibrations. We illustrate this technique with applications from the analysis of the ANITA-I and ANITA-II data in the 200-1200 MHz band.

astro-ph.IM↗

arXiv2009

IceRay: An IceCube-centered Radio-Cherenkov GZK Neutrino Detector

We discuss design considerations and simulation results for IceRay, a proposed large-scale ultra-high energy (UHE) neutrino detector at the South Pole. The array is designed to detect the coherent Askaryan radio emission from UHE neutrino interactions in the ice, with the goal of detecting the cosmogenic neutrino flux with reasonable event rates. Operating in coincidence with the IceCube neutrino detector would allow complete calorimetry of a subset of the events. We also report on the status of a testbed IceRay station which incorporates both ANITA and IceCube technology and will provide year-round monitoring of the radio environment at the South Pole.

astro-ph.HE↗

arXiv2008

New Limits on the Ultra-high Energy Cosmic Neutrino Flux from the ANITA Experiment

We report initial results of the first flight of the Antarctic Impulsive Transient Antenna (ANITA-1) 2006-2007 Long Duration Balloon flight, which searched for evidence of a diffuse flux of cosmic neutrinos above energies of 3 EeV. ANITA-1 flew for 35 days looking for radio impulses due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. We report here on our initial analysis, which was performed as a blind search of the data. No neutrino candidates are seen, with no detected physics background. We set model-independent limits based on this result. Upper limits derived from our analysis rule out the highest cosmogenic neutrino models. In a background horizontal-polarization channel, we also detect six events consistent with radio impulses from ultra-high energy extensive air showers.

astro-ph↗

arXiv2008

The Antarctic Impulsive Transient Antenna Ultra-high Energy Neutrino Detector Design, Performance, and Sensitivity for 2006-2007 Balloon Flight

We present a detailed report on the experimental details of the Antarctic Impulsive Transient Antenna (ANITA) long duration balloon payload, including the design philosophy and realization, physics simulations, performance of the instrument during its first Antarctic flight completed in January of 2007, and expectations for the limiting neutrino detection sensitivity. Neutrino physics results will be reported separately.

astro-ph↗

arXiv2004

Prospects for radio detection of ultra-high energy cosmic rays and neutrinos

The origin and nature of the highest energy cosmic ray events is currently the subject of intense investigation by giant air shower arrays and fluorescent detectors. These particles reach energies well beyond what can be achieved in ground-based particle accelerators and hence they are fundamental probes for particle physics as well as astrophysics. Because of the scarcity of these high-energy particles, larger and larger ground-based detectors have been built. The new generation of digital radio telescopes may play an important role in this, if properly designed. Radio detection of cosmic ray showers has a long history but was abandoned in the 1970's. Recent experimental developments together with sophisticated air shower simulations incorporating radio emission give a clearer understanding of the relationship between the air shower parameters and the radio signal, and have led to resurgence in its use. Observations of air showers by the SKA could, because of its large collecting area, contribute significantly to measuring the cosmic ray spectrum at the highest energies. Because of the large surface area of the moon, and the expected excellent angular resolution of the SKA, using the SKA to detect radio Cherenkov emission from neutrino-induced cascades in lunar regolith will be potentially the most important technique for investigating cosmic ray origin at energies above the photoproduction cut-off. (abridged)

astro-ph↗

arXiv1997

VERITAS: Very LArge Energetic Radiation Imaging Telescope Array System

A next generation atmospheric Cherenkov observatory is described based on the Whipple Observatory $γ$-ray telescope. A total of nine such imaging telescopes will be deployed in an array that will permit the maximum versatility and give high sensitivity in the 50 GeV - 50 TeV band (with maximum sensitivity from 100 GeV to 10 TeV).

astro-ph↗