The Radio Detection Technique#
In-Ice Askaryan Emission#
- Shower#
In particle physics, a shower is a cascade of secondary particles produced as the result of a high-energy particle interacting with dense matter (Wikipedia).
- Electromagnetic shower#
Denoted by \(X\).
An EM shower begins when a high-energy electron, positron or photon enters a material. At high energies, in which the photoelectric effect and Compton scattering are insignificant, photons interact with matter primarily via pair production – that is, they convert into an electron-positron pair, interacting with an atomic nucleus or electron in order to conserve momentum. High-energy electrons and positrons primarily emit photons, a process called bremsstrahlung… Pair production and bremsstrahlung continue, leading to a cascade of particles of decreasing energy until phtotons fall below the pair production threshold.
See the [Wikipedia page on EM showers] (https://en.wikipedia.org/wiki/Particle_shower#Electromagnetic_showers)
- Hadronic shower#
Hadronic showers are produced by hadrons (i.e. nucleons and other particles made of quarks), and proceed mostly via the strong nuclear force.
Geomagnetic Emission form Air Showers#
“The EAS \(\tau\) channel typically has a lower energy threshold than the Askaryan channel. Due to the narrow emission cone, the overall aperture is less [?] once the Askaryan channel threshold is exceeded.”
This is saying that at lower energies, the \(\tau\) channel can see better.
Fig. 19 A qualitative figure showing the efficiency of the \(\tau\) channel versus the Askaryan channel.#
Radio Detection Platforms#
“…larger aperature generally comes at the price of a higher threshold…”
ie. “Threshold” below which we cannot detect.