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Krijn de Vries

Publications and source records attributed to Krijn de Vries.

7 recordsLinked to original sources

NuRadioMC: Simulating the radio emission of neutrinos from interaction to detector

NuRadioMC is a Monte Carlo framework designed to simulate ultra-high energy neutrino detectors that rely on the radio detection method. This method exploits the radio emission generated in the electromagnetic component of a particle shower following a neutrino interaction. NuRadioMC simulates everything from the neutrino interaction in a medium, the subsequent Askaryan radio emission, the propagation of the radio signal to the detector and finally the detector response. NuRadioMC is designed as a modern, modular Python-based framework, combining flexibility in detector design with user-friendliness. It includes a state-of-the-art event generator, an improved modelling of the radio emission, a revisited approach to signal propagation and increased flexibility and precision in the detector simulation. This paper focuses on the implemented physics processes and their implications for detector design. A variety of models and parameterizations for the radio emission of neutrino-induced showers are compared and reviewed. Comprehensive examples are used to discuss the capabilities of the code and different aspects of instrumental design decisions.

astro-ph.IM↗

Validation of straight-line signal propagation for radio signal of very inclined cosmic ray air showers

An ongoing challenge for radio-based detectors of high-energy cosmic particles is the accurate description of radio signal propagation in natural nonuniform media. For radio signals originating from extensive air showers, the current state of the art simulations often implicitly assume straight-line signal propagation. The refraction due to a nonuniform atmosphere is however expected to have an effect on the received signal and associated reconstruction. This effect is currently not completely understood for the most inclined geometries. Here, we present a study regarding the validity of straight-line signal propagation when simulating radio emission associated with very inclined air shower geometries. To this end, the calculation of the electric field based on the end point formalism used in CoREAS was improved by use of tabulated ray tracing data. We find a difference of 2% in radiation energy and a difference of O(0.01°) on direction reconstruction when working at frequencies below 600 MHz. We thus find that, for frequencies up to 600 MHz and zenith angles up to 88°, the current straight-line based simulation approaches are accurate.

astro-ph.HE↗

Probing neutrino emission at GeV energies from compact binary mergers with IceCube

The advent of Multi-Messenger Astronomy has allowed for new types of source searches within the neutrino community. We present the results of the first search for GeV astrophysical neutrinos emitted from Compact Binary Mergers, i.e. binary black hole or binary neutron star mergers, detected by the LIGO and Virgo interferometers. We introduce a new approach that lowers the energy threshold of IceCube from roughly 10 GeV to <1 GeV. This method uses an innovative event selection of GeV neutrino events in IceCube and searches for a statistically significant increase in the amount of GeV-like events detected around the Compact Binary Merger time. We compare our results with constraints set by high-energy neutrino searches, and describe the complementarity of these low and high-energy searches.

astro-ph.HE↗

Radio Morphing: towards a fast computation of the radio signal from air showers

Over the last years, radio detection has matured to become a competitive method for the detection of air showers. Arrays of thousands of antennas are now envisioned for the detection of cosmic rays of ultra high energy or neutrinos of astrophysical origin. The data exploitation of such detectors requires to run massive air-shower simulations to evaluate the radio signal at each antenna position. In order to reduce the associated computational cost, we have developed a semi-analytical method for the computation of the emitted radio signal called Radio Morphing. The method consists in computing the radio signal of any air-shower at any location from the simulation of one single reference shower at given positions by i) a scaling of the electric-field amplitude of this reference shower, ii) an isometry on the simulated positions and iii) an interpolation of the radio pulse at the desired position. This technique enables one to compute electric field time traces with characteristics very similar to those obtained with standard computation methods, but with computation times reduced by several orders of magnitude. In this paper, we present this novel tool, explain its methodology, and discuss its limitations. Furthermore, we validate the method on a typical event set for the future GRAND experiment showing that the calculated peak amplitudes are consistent with the results from ZHAireS simulations with a mean offset of +8.5% and a standard deviation of 27.2% in this specific case. This overestimation of the signal strength by Radio Morphing arises mainly from the choice of the underlying reference shower.

astro-ph.IM↗

Radio Morphing - towards a fast computation of the radio signal from air-showers

Over the last decades, radio detection of air showers has been established as a promising detection technique for ultrahigh-energy cosmic rays and neutrinos. Very large or dense antenna arrays are necessary to be proficient at collecting information about these particles and understanding their properties accurately. The exploitation of such arrays requires to run massive air-shower simulations to evaluate the radio signal at each antenna position, taking into account features such as the ground topology. In order to reduce computational costs, we have developed a fast computation of the emitted radio signal on the basis of generic shower simulations, called Radio Morphing. The method consists in the calculation of the radio signal of any air-shower by i) a scaling of the electric-field amplitude of a reference air shower to the target shower, ii) an isometry on the simulated positions and iii) an interpolation of the radio pulse at the desired position. This technique enables one to gain many orders of magnitude in CPU time compared to a standard computation. In this contribution, we present this novel tool and explain its methodology. In particular, Radio Morphing will be a key element for the simulation chain of the Giant Radio Array for Neutrino Detection (GRAND) project, that aims at detecting ultra-high-energy neutrinos with an array of 200 000 radio antennas in mountainous regions.os with an array of 200 000 radio antennas in mountainous regions.

astro-ph.IM↗

Radio Morphing - towards a full parametrisation of the radio signal from air showers

Over the last decades, radio detection of air showers has been established as a detection technique for ultra-high-energy cosmic-rays impinging on the Earth's atmosphere with energies far beyond LHC energies. Today's second-generation of digital radio-detection experiments, as e.g. AERA or LOFAR, are becoming competitive in comparison to already standard techniques e.g. fluorescence light detection. Thanks to a detailed understanding of the physics of the radio emission in extensive air showers, simulations of the radio signal are already successfully tested and applied in the reconstruction of cosmic rays. However, the limits of the computational power resources are easily reached when it comes to computing electric fields at the numerous positions requested by large or dense antenna arrays. In the case of mountainous areas as e.g. for the GRAND array, where 3D shower simulations are necessary, the problem arises with even stronger acuity. Therefore we developed a full parametrisation of the emitted radio signal on the basis of generic shower simulations which will reduce the simulation time by orders of magnitudes. In this talk we will present this concept after a short introduction to the concept of the radio detection of air-shower induced by cosmic rays.

astro-ph.IM↗