Modelling of radio emission in the SLAC T-510 Experiment using microscopic Geant4 simulations

Abstract

The SLAC T-510 experiment was designed to verify established microscopic models for simulation of radio emission from air-showers by reproducing the physics under controlled lab conditions. For this verification, the simulation toolkit Geant4 was expanded by the calculation of the emitted radio signal with the "endpoint" and the "ZHS" formalisms in parallel. We present and compare the results of the two simulation approaches, taking into account the details of the experimental set-up such as the beam energy, target geometry and material, and the magnetic field configuration. We put special emphasis on the discussion of the effects due to refraction and transition radiation and show a comparison of the simulation results with the measured data of the SLAC T-510 Experiment.

Radio detection of cosmic ray air showers in the digital era

“…Cross-checks between the ZHS and endpoints formalisms have been made in the context of the SLAC T-510 experiment [55], indicating that the formalisms produce results agreeing within ≈ 5% of each other [56]. It is thus likely that deviations between CoREAS and ZHAireS are related mostly to the underlying air shower simulation between AIRES and CORSIKA, possibly related to hadronic interaction models and/or the choice of energy cuts for the simulation of the particle cascade.…”

SLAC T-510: A beam-line experiment for radio emission from particle cascades in the presence of a magnetic field

“…The simulations are described in details in Ref. [2]. The systematic uncertainty between the models does not exceed 3% in the peak-to-peak amplitudes or in the frequency spectra in the 30-1400 MHz range.…”

Measurements, system response, and calibration of the SLAC T-510 Experiment

“…Combined with the GEANT 4.10 toolkit, they provide the predictions for the radio emission in the SLAC T-510 experiemnt. are discussed in more detail in [7]. We describe here the experimental data and system calibration used for such comparisons.For a discussion of the simulations developed for this experiment, see Zilles et al in these proceedings [7].…”

“…Because the vertical (B z ) field falls off near the edges of the coils, we placed the edge of the target in the middle of the first coil. Along the beam position, the average magnetic field in the vertical direction is -845 G, and the root-mean-squared variation is 72 G. In our simulations of the T-510 experiment, we included the measured, three-dimensional magnetic field [7].…”

“…5 shows power spectral densities measured at several positions (1.30 m, 6.52 m,11.29 m) above the beam height and 13.47 m from the point where the beam enters the target. The spectra are compared with simulations following the ZHS and Endpoints formalisms [7] that are convolved with the effective height and system response shown in Fig. 4.…”