scholarly journals A Scintillator and Radio Enhancement of the IceCube Surface Detector Array

2019 ◽  
Vol 210 ◽  
pp. 06009
Author(s):  
Andreas Haungs
Keyword(s):  
Galactic Center ◽  
Cosmic Ray ◽  
Snow Accumulation ◽  
Mass Composition ◽  
Scintillation Detectors ◽  
Window Of Opportunity ◽  
Hadronic Interaction ◽  
Surface Detector ◽  
The Impact ◽  
Minimal Effort

An upgrade of the present IceCube surface array (IceTop) with scintillation detectors and possibly radio antennas is foreseen. The enhanced array will calibrate the impact of snow accumulation on the reconstruction of cosmic-ray showers detected by IceTop as well as improve the veto capabilities of the surface array. In addition, such a hybrid surface array of radio antennas, scintillators and Cherenkov tanks will enable a number of complementary science targets for IceCube such as enhanced accuracy to mass composition of cosmic rays, search for PeV photons from the Galactic Center, or more thorough tests of the hadronic interaction models. Two prototype stations with 7 scintillation detectors each have been already deployed at the South Pole in January 2018. These R&D studies provide a window of opportunity to integrate radio antennas with minimal effort.

scholarly journals Study of muons from ultrahigh energy cosmic ray air showers measured with the Telescope Array experiment

2019 ◽  
Vol 210 ◽  
pp. 02012
Author(s):  
R. Takeishi
Keyword(s):  
Interaction Model ◽  
Cosmic Ray ◽  
Mass Composition ◽  
Ultrahigh Energy ◽  
Air Showers ◽  
Hadronic Interaction ◽  
Telescope Array ◽  
Interaction Models ◽  
Air Shower ◽  
Number Of Particles

One of the uncertainties in ultrahigh energy cosmic ray (UHECR) observation derives from the hadronic interaction model used for air shower Monte-Carlo (MC) simulations. One may test the hadronic interaction models by comparing the measured number of muons observed at the ground from UHECR induced air showers with the MC prediction. The Telescope Array (TA) is the largest experiment in the northern hemisphere observing UHECR in Utah, USA. It aims to reveal the origin of UHECRs by studying the energy spectrum, mass composition and anisotropy of cosmic rays by utilizing an array of surface detectors (SDs) and fluorescence detectors. We studied muon densities in the UHE extensive air showers by analyzing the signal of TA SD stations for highly inclined showers. On condition that the muons contribute about 65% of the total signal, the number of particles from air showers is typically 1.88 ± 0.08 (stat.) ± 0.42 (syst.) times larger than the MC prediction with the QGSJET II-03 model for proton-induced showers. The same feature was also obtained for other hadronic interaction models, such as QGSJET II-04.

scholarly journals Measurements of UHECR Mass Composition by Telescope Array

2019 ◽  
Vol 210 ◽  
pp. 01008
Author(s):  
William Hanlon
Keyword(s):  
Monte Carlo ◽  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Second Moments ◽  
Systematic Uncertainties ◽  
Surface Detector

Telescope Array (TA) has recently published results of nearly nine years of Xmax observations providing its highest statistics measurement of ultra high energy cosmic ray (UHECR) mass composition to date for energies exceeding 1018.2 eV. This analysis measured agreement of observed data with results expected for four different single elements. Instead of relying only on the first and second moments of Xmax distributions, we employ a morphological test of agreement between data and Monte Carlo to allow for systematic uncertainties in data and in current UHECR hadronic models. Results of this latest analysis and implications of UHECR composition observed by TA are presented. TA can utilize different analysis methods to understand composition as both a crosscheck on results and as a tool to understand systematics affecting Xmax measurements. The different analysis efforts utilizing fluorescence detector stereo, surface detector and fluorescence detector hybrid, and surface detector-only, currently underway at TA performed to understand composition are also discussed.

scholarly journals Recent results from the Pierre Auger Observatory

2019 ◽  
Vol 208 ◽  
pp. 08001 ◽  
Author(s):  
Sergio Petrera
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Large Scale ◽  
Cosmic Ray ◽  
Pierre Auger Observatory ◽  
Mass Composition ◽  
Arrival Direction ◽  
Wide Range ◽  
Surface Detector

In this paper some recent results from the Pierre Auger Collaboration are presented. These are the measurement of the energy spectrum of cosmic rays over a wide range of energies (1017.5 to above 1020 eV), studies of the cosmic-ray mass composition with the fluorescence and surface detector of the Observatory, the observation of a large-scale anisotropy in the arrival direction of cosmic rays above 8 × 1018 eV and indications of anisotropy at intermediate angular scales above 4 × 1019 eV. The astrophysical implications of the spectrum and composition results are also discussed. Finally the progress of the upgrade of the Observatory, AugerPrime is presented.

scholarly journals Physics Potential of a Radio Surface Array at the South Pole

2019 ◽  
Vol 216 ◽  
pp. 01007 ◽  
Author(s):  
Frank G. Schröder
Keyword(s):  
Cosmic Rays ◽  
Galactic Center ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Mass Composition ◽  
Air Showers ◽  
Physics Potential ◽  
Shower Maximum ◽  
Mass Dependent ◽  
Near Future

A surface array of radio antennas will enhance the performance of the IceTop array and enable new, complementary science goals. First, the accuracy for cosmic-ray air showers will be increased since the radio array provides a calorimetric measurement of the electromagnetic component and is sensitive to the position of the shower maximum. This enhanced accuracy can be used to better measure the mass composition, to search for possible mass-dependent anisotropies in the arrival directions of cosmic rays, and for more thorough tests of hadronic interaction models. Second, the sensitivity of the radio array to inclined showers will increase the sky coverage for cosmic-ray measurements. Third, the radio array can be used to search for PeV photons from the Galactic Center. Since IceTop is planned to be enhanced by a scintillator array in the near future, a radio extension sharing the same infrastructure can be installed with minimal additional effort and excellent scientific prospects. The combination of ice-Cherenkov, scintillation, and radio detectors at IceCube will provide unprecedented accuracy for the study of highenergy Galactic cosmic rays.

scholarly journals Simulation study on the effects of diffractive collisions on the prediction of the observables in ultra-high-energy cosmic ray experiments

2021 ◽  
Author(s):  
Ken Ohashi ◽  
Hiroaki Menjo ◽  
Yoshitaka Itow ◽  
Takashi Sako ◽  
Katsuaki Kasahara
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Hadronic Interaction ◽  
Open Problems ◽  
Cross Sectional ◽  
High Energy Cosmic Rays ◽  
The Cross ◽  
Mass Dependent

Abstract The mass composition of ultra-high-energy cosmic rays is important for understanding their origin. Owing to our limited knowledge of the hadronic interaction, the interpretations of the mass composition from observations include several open problems, such as the inconsistent interpretations of ⟨Xmax⟩ and ⟨Xμmax⟩. Futhermore, the large difference between the predictions exists by the hadronic interaction models. Diffractive collision is one of the proposed sources of the uncertainty. In this paper, we discuss the effect of the detailed characteristics of diffractive collisions to the observables of ultra-high-energy cosmic-ray experiments, focusing on three detailed characteristics. These are the cross-sectional fractions of different collision types, diffractive-mass spectrum, and diffractive-mass-dependent particle productions from the diffractive dissociation system. We demonstrated that the current level of the uncertainty in the cross-sectional fraction can affect 8.9 g/cm2 of ⟨Xmax⟩ and 9.4 g/cm2 of ⟨Xμmax⟩, whereas the other details of the diffractive collisions exhibit relatively minor effects.

scholarly journals Tests of hadronic interactions with measurements by Pierre Auger Observatory

2019 ◽  
Vol 208 ◽  
pp. 08003 ◽  
Author(s):  
Raul R. Prado
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Mass Composition ◽  
Air Showers ◽  
Hadronic Interaction ◽  
Interaction Models ◽  
Hadronic Interactions ◽  
Air Shower ◽  
Muon Production

The hybrid design of the Pierre Auger Observatory allows for the measurement of a number of properties of extensive air showers initiated by ultra-high energy cosmic rays. By comparing these measurements to predictions from air shower simulations, it is possible to both infer the cosmic ray mass composition and test hadronic interactions beyond the energies reached by accelerators. In this paper, we will present a compilation of results of air shower measurements by the Pierre Auger Observatory which are sensitive to the properties of hadronic interactions and can be used to constrain the hadronic interaction models. The inconsistencies found between the interpretation of different observables with regard to primary composition and between their measurements and simulations show that none of the currently used hadronic interaction models can provide a proper description of air showers and, in particular, of the muon production.

scholarly journals Cosmic-ray neutron method for the continuous measurement of Arctic snow accumulation and melt

2021 ◽  
Author(s):  
Anton Jitnikovitch ◽  
Philip Marsh ◽  
Branden Walker ◽  
Darin Desilets
Keyword(s):  
Water Resource Management ◽  
Snow Water Equivalent ◽  
Pearson Correlation ◽  
Cosmic Ray ◽  
Snow Accumulation ◽  
The Arctic ◽  
Southern Ontario ◽  
Sensing Applications ◽  
The Impact

Abstract. The Arctic is warming at two to three times the rate of the global average, significantly impacting snow accumulation and melt. Unfortunately, conventional methods to measure snow water equivalent (SWE), a key aspect of the Arctic snow cover, have numerous limitations that hinder our ability to document annual cycles, the impact of climate change, or to test predictive models. As a result, there is an urgent need for improved methods that measure Arctic SWE; allow for continuous, unmanned measurements over the entire winter; and allow measurements that are representative of spatially variable, Arctic snow covers. In-situ, or invasive, cosmic ray neutron sensors (CRNSs) may fill this observational gap, but few studies have tested these types of sensors or considered their applicability at remote sites in the Arctic. During the winters of 2016/17 and 2017/18 we tested an in-situ CRNS system at two locations in Canada; a cold, low- to high-SWE environment in the Canadian Arctic and at a warm, low-SWE landscape in Southern Ontario that allowed easier access for validation purposes. CRNS moderated neutron counts were compared to manual snow survey SWE values obtained during both winter seasons. Pearson correlation coefficients ranged from −0.89 to −0.98, while regression analyses provided R2 values from 0.79 to 0.96. RMSE of the CRNS-measured SWE averaged 2 mm at the southern Ontario site and ranged from 28 to 40 mm at the Arctic site. These data show that in-situ CRNS instruments are able to continuously measure SWE with sufficient accuracy, and have important applications for measuring SWE in a variety of environments, including remote Arctic locations. These sensors can provide important SWE data for testing snow and hydrological models, water resource management applications, and the validation of remote-sensing applications.

scholarly journals Nautilus multi-grain model: Importance of cosmic-ray-induced desorption in determining the chemical abundances in the ISM

2018 ◽  
Vol 615 ◽  
pp. A20 ◽  
Author(s):  
Wasim Iqbal ◽  
Valentine Wakelam
Keyword(s):  
Grain Size ◽  
Surface Temperature ◽  
Gas Phase ◽  
Numerical Models ◽  
Cosmic Ray ◽  
Grain Sizes ◽  
Small Grains ◽  
Grain Model ◽  
Grain Surface ◽  
The Impact

Context. Species abundances in the interstellar medium (ISM) strongly depend on the chemistry occurring at the surfaces of the dust grains. To describe the complexity of the chemistry, various numerical models have been constructed. In most of these models, the grains are described by a single size of 0.1 μm. Aims. We study the impact on the abundances of many species observed in the cold cores by considering several grain sizes in the Nautilus multi-grain model. Methods. We used grain sizes with radii in the range of 0.005 μm to 0.25 μm. We sampled this range in many bins. We used the previously published, MRN and WD grain size distributions to calculate the number density of grains in each bin. Other parameters such as the grain surface temperature or the cosmic-ray-induced desorption rates also vary with grain sizes. Results. We present the abundances of various molecules in the gas phase and also on the dust surface at different time intervals during the simulation. We present a comparative study of results obtained using the single grain and the multi-grain models. We also compare our results with the observed abundances in TMC-1 and L134N clouds. Conclusions. We show that the grain size, the grain size dependent surface temperature and the peak surface temperature induced by cosmic ray collisions, play key roles in determining the ice and the gas phase abundances of various molecules. We also show that the differences between the MRN and the WD models are crucial for better fitting the observed abundances in different regions in the ISM. We show that the small grains play a very important role in the enrichment of the gas phase with the species which are mainly formed on the grain surface, as non-thermal desorption induced by collisions of cosmic ray particles is very efficient on the small grains.

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