We discuss the radar detection technique as a probe for high-energy cosmic neutrino induced particle cascades in a dense medium like ice. With the recent detection of high-energy cosmic neutrinos by ...the IceCube neutrino observatory the window to neutrino astronomy has been opened. We discuss a new technique to detect cosmic neutrinos at even higher energies than those covered by IceCube, but with an energy threshold below the currently operating Askaryan radio detectors. A calculation for the radar return power, as well as first experimental results will be presented.
In recent works we discussed the feasibility of the radar detection technique as a new method to probe high-energy cosmic-neutrino induced plasmas in ice. Using the different properties of the ...induced ionization plasma, an energy threshold of several PeV was derived for the over-dense scattering of a radio wave off the plasma. Next to this energy threshold the radar return power was determined for the different constituents of the plasma. It followed that the return signal should be detectable at a distance of several hundreds of meters to a few kilometers, depending on the plasma constituents and considered geometry. In this article we describe a more detailed modeling of the scattering process by expanding our model to include the full shower geometry, as well as the reflection off the under-dense plasma region. We include skin-effects, as well as the angular dependence of the scattered signal. As a first application of this more detailed modeling approach, we provide the effective area and sensitivity for a simplified detector setup. It follows that, depending on the detailed plasma properties, the radar detection technique provides a very promising method for the detection of neutrino induced particle cascades at energies above several PeV. Nevertheless, to determine the feasibility of the method more detailed information about the plasma properties, especially its lifetime and the free charge collision rate, are needed.
We have developed a code that semi-analytically calculates the radio footprint (intensity and polarization) of an extensive air shower subject to atmospheric electric fields. This can be used to ...reconstruct the height dependence of atmospheric electric field from the measured radio footprint. The various parameterizations of the spatial extent of the induced currents are based on the results of Monte-Carlo shower simulations. The calculated radio footprints agree well with microscopic CoREAS simulations.
TREND50 is a radio detection setup of 50 self-triggered antennas working in the 50-100MHz frequency range and deployed in a radio-quiet valley of the Tianshan mountains (China). TREND50 achieved its ...goal: the autonomous radiodetection and identification of air showers. Thanks to a dedicated offine selection algorithm, 564 air shower candidates were indeed selected out of \(7\cdot10^8\) transient radio signals recorded during the 314 live days of data taken during the first two years of operation of this setup (2011 and 2012). This event rate, as well as the distribution of the candidate directions of arrival, is consistent with what is expected from cosmic-ray-induced air showers according to simulations, assuming an additional \(\sim\)20% contamination of the final sample by background events. This result is obtained at the cost of a reduced air shower detection efficiency, estimated to be \(\sim\)3%. This low efficiency is mostly due to the large amount of dead time of the setup. This result paves the way for the GRANDProto35 experiment, the first stage of the GRAND project.
In this article we try to answer the question whether the radar detection technique can be used for the detection of high-energy-neutrino induced particle cascades in ice. A high-energy neutrino ...interacting in ice will induce a particle cascade, also referred to as a particle shower, moving at approximately the speed of light. Passing through, the cascade will ionize the medium, leaving behind a plasma tube. The different properties of the plasma-tube, such as its lifetime, size and the charge-density will be used to obtain an estimate if it is possible to detect this tube by means of the radar detection technique. Next to the ionization electrons a second plasma due to mobile protons induced by the particle cascade is discussed. An energy threshold for the cascade inducing particle of 4 PeV for the electron plasma, and 20 PeV for the proton plasma is obtained. This allows the radar detection technique, if successful, to cover the energy-gap between several PeV and a few EeV in the currently operating neutrino detectors, where on the low side IceCube runs out of events, and on the high side the Askaryan radio detectors begin to have large effective volumes.
Organoids are self‐organizing 3D structures grown from stem cells that recapitulate essential aspects of organ structure and function. Here, we describe a method to establish long‐term‐expanding ...human airway organoids from broncho‐alveolar resections or lavage material. The pseudostratified airway organoids consist of basal cells, functional multi‐ciliated cells, mucus‐producing secretory cells, and CC10‐secreting club cells. Airway organoids derived from cystic fibrosis (CF) patients allow assessment of CFTR function in an organoid swelling assay. Organoids established from lung cancer resections and metastasis biopsies retain tumor histopathology as well as cancer gene mutations and are amenable to drug screening. Respiratory syncytial virus (RSV) infection recapitulates central disease features, dramatically increases organoid cell motility via the non‐structural viral NS2 protein, and preferentially recruits neutrophils upon co‐culturing. We conclude that human airway organoids represent versatile models for the in vitro study of hereditary, malignant, and infectious pulmonary disease.
Synopsis
To date, persistent in vitro culture of adult human lung epithelium remains elusive. In this methods resource article, culture conditions to maintain three‐dimensional pulmonary tissue long‐term are reported and applied to recapitulate related diseases.
Culture conditions for long‐term expansion of healthy, hereditary disease and malignant human airway epithelial organoids.
Airway organoids are amenable for medium‐throughput drug screening.
Airway organoids readily allow modelng of viral infection.
Three‐dimensional human pulmonary tissue culture allows for investigation of hereditary diseases.
We report on the measurement of coherent radio emission from the electron beam sudden appearance at the Telescope Array Electron Light Source facility. This emission was detected by four independent ...radio detector setups sensitive to frequencies ranging from 50 MHz up to 12.5 GHz. We show that this phenomenon can be understood as a special case of coherent transition radiation by comparing the observed results with simulations. The in-nature application of this signal is given by the emission of cosmic ray or neutrino induced particle cascades traversing different media such as air, rock and ice.
Radio detection of cosmic-ray-induced air showers has come to a flight the last decade. Along with the experimental efforts, several theoretical models were developed. The main radio-emission ...mechanisms are established to be the geomagnetic emission due to deflection of electrons and positrons in Earth's magnetic field and the charge-excess emission due to a net electron excess in the air shower front. It was only recently shown that Cherenkov effects play an important role in the radio emission from air showers. In this article we show the importance of these effects to extract quantitatively the position of the shower maximum from the radio signal, which is a sensitive measure for the mass of the initial cosmic ray. We also show that the relative magnitude of the charge-excess and geomagnetic emission changes considerably at small observer distances where Cherenkov effects apply.
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