Cosmic Rays In Atmosphere Research Articles

Probing the angular distribution of terrestrial cosmic-ray nuclei

Understanding how atmospheric cosmic-rays are distributed on Earth is crucial for simulating cosmic-ray setups and detectors for rare-event detection. The accuracy and reliability of such simulations and experiments depend on obtaining this information. This study focuses on analyzing the impact of key parameters in the PARMA model on the angular distributions of terrestrial cosmic-ray nuclei. These parameters include geomagnetic cut-off rigidity, atmospheric depth and solar activity. Moreover, angular distributions of various particles, including protons, electrons, neutrons, and muons, were systematically calculated over relevant rigidities, solar modulations, and altitudes. For this purpose, the latest version of the Excel-based Program for calculating Atmospheric Cosmic-ray Spectrum EXPACS (v.4.13), which relies on updated experimental data, was used. The results of the calculations showed clear trends in the angular distributions of all cosmic-ray species as a function of the model parameters. These findings provide valuable insights into the dynamics of cosmic rays in our solar system. Moreover, they can contribute to developing more accurate models for predicting the distribution of cosmic rays on the Earth's surface.

A review on natural background concentration of beryllium prevalent in ambient air and different environmental matrices

Abstract Beryllium, the 44th most abundant element in the Earth’s crust, is found ubiquitously in environmental matrices, including air, soil, and water, as well as in a variety of food items such as grains, fruits, and vegetables. The typical concentration of Be in air is reported to be ~0.05 ng/m3, whereas in soil, its concentration varies from ~2 to 5 ppm. The prevalence of Be in soil leads to its presence in water as well as in plants, and various human activities such as burning of coal, petrol, diesel, mining, and other industrial activities may further increase the concentration of beryllium in environment and associated matrices. It needs to be mentioned that the typical concentration of Be in food items is of the order of few ppb, whereas in drinking water, the typical values are reported to be <1 ppb or so. Based on the literature survey including some of the most recent studies, the present paper provides summary on concentration of Be in air, soil, and other relevant matrices as concise and consolidated reports on beryllium are scarce. In addition, related information like Be in drinking water along with available guidelines is also provided. Information on the prevalence of other isotopes of beryllium, i.e., 7Be4 and 10Be4, which are radioactive and are produced by cosmic rays in atmosphere, is also included in the present paper.

Mountain Muon Tomography Using a Liquid Scintillator Detector

Muon tomography (MT), based on atmospheric cosmic rays, is a promising technique suitable for nondestructive imaging of the internal structures of mountains. This method uses the measured flux distribution after attenuation, combined with the known muon angular and energy distributions and a 3D satellite map, to perform tomographic imaging of the density distribution inside a probed volume. A muon tomography station (MTS) requires direction-sensitive detectors with a high resolution for optimal tracking of incident cosmic-ray muons. The spherical liquid scintillator detector is one of the best candidates for this application due to its uniform detection efficiency for the whole 4π solid angle and its excellent ability to distinguish muon signals from the radioactive background via the difference in the energy deposit. This type of detector, with a 1.3 m diameter, was used in the Jinping Neutrino Experiment (JNE). Its angular resolution is 4.9 degrees. Following the application of imaging for structures of Jinping Mountain with JNE published results based on the detector, we apply it to geological prospecting. For mountains below 1 km in height and 2.8 g/cm3 in the reference rock, we demonstrate that this kind of detector can image internal regions with densities of ≤2.1 g/cm3 or ≥3.5 g/cm3 and hundreds of meters in size.

Feasibility Studies of Charge Exchange Measurements in pp Collisions at the LHC

(1) Pions produced in the development of extended atmospheric cosmic ray air showers subsequently decay to muons. The measured yield of those muons is generally underestimated by current phenomenological models and event generators optimized for cosmic ray physics. The importance of those disagreements motivates the feasibility studies for testing these models at the Large Hadron Collider (LHC) energies, at the highest center-of-mass energies achievable in a laboratory. The interaction of a nucleus and a virtual pion created in a charge exchange reaction at the LHC is a similar process to those contributing to the development of air showers in case of cosmic rays. The crucial problem of such an analysis is the selection of charge exchange events with the highest possible efficiency and high purity from proton–proton collisions at the LHC. (2) For this we consider distributions of various measurable quantities given by event generators commonly used in cosmic ray physics. (3) We examine the expected distributions of energy deposited in different calorimeters of an LHC experiment. We consider the geometrical acceptance and energy resolution of the detectors at the Compact Muon Solenoid (CMS) experiment, as an example. We determine a working point cut from the various options for event selection, and compare signal and background predictions using different models for a representative simple observable, such as average transverse momentum or charge particle yield. (4) A set of event selection cuts along these considerations is proposed, with the aim of achieving optimal efficiency and purity.

Calculation of the atmospheric cosmic ray flux and dosimetry with EXPACS code

Calculation of the atmospheric cosmic ray flux and dosimetry with EXPACS code

Microstructures and properties of CrxFeNi(3-x)Al high-entropy alloys

Muon tomography (MT), based on atmospheric cosmic rays, is a promising technique suitable for nondestructive imaging of the internal structures of mountains. This method uses the measured flux distribution after attenuation, combined with the known muon angular and energy distributions and a 3D satellite map, to perform tomographic imaging of the density distribution inside a probed volume. A muon tomography station (MTS) requires direction-sensitive detectors with a high resolution for optimal tracking of incident cosmic-ray muons. The spherical liquid scintillator detector is one of the best candidates for this application due to its uniform detection efficiency for the whole $4\pi$ solid angle and its excellent ability to distinguish muon signals from the radioactive background via the difference in the energy deposit. This type of detector, with a 1.3~m diameter, was used in the Jinping Neutrino Experiment~(JNE). Its angular resolution is 4.9~degrees. Following the application of imaging for structures of Jinping Mountain with JNE published results based on the detector, we apply it to geological prospecting. For mountains below 1~km in height and 2.8~${\rm g}/{\rm cm}^3$ in the reference rock, we demonstrate that this kind of detector can image internal regions with densities of $\leq$ 2.1~${\rm g}/{\rm cm}^3$ or $\geq$ 3.5~${\rm g}/{\rm cm}^3$ and hundreds of meters in size.

The reliability of muography applied in the detection of the animal burrows within River Levees validated by means of geophysical techniques

Animal burrows in a river's earthen levee leads to water piping phenomena causing structural damage and eventual collapse during floods. Currently, the state of the art comprises case studies that deal with management and maintenance, while very few documents attempt at assessing possible animal-induced failure mechanisms. For the latter, detection and characterisation of the animal burrows is crucial and Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar are the most employed geophysical techniques. Between 2017 and 2018 a team of physicists, engineering geologists, and geophysicists has for the first time probed the possibility of exploiting the Muon Transmission Radiography (MTR) to verify the internal conservation status of levees that were visibly damaged by animal activities. The technique is a non-invasive method, currently under development, based on the detection of muons, a highly penetrating component of atmospheric cosmic rays. MTR is capable of providing angular maps of the average density of the material present in front of the detector. A test site measurement campaign was carried out with a prototype instrument placed at the side of the levee. This new survey methodology was compared to a more traditional ERT measurement, performed with a pole-dipole and dipole-dipole configuration. Moreover, the actual burrows' distribution was mapped during the demolition works using Terrestrial Laser Scanner measurements to validate and constrain results. The comparison between ERT and MTR maps shows that, in spite of some limitations, the latter is a suitable and promising technique that could successfully complement a program of geological risk assessment.

Simulation of atmospheric cosmic-rays and their impacts based on pre-calculated databases, physical models and computational methods

The atmospheric cosmic-ray environment is composed of secondary particles produced when primary cosmic rays interact with the nucleus of atmospheric atoms. Modeling of atmospheric radiations is essential for investigating their impacts on human activities such as radiation risks in aviation or scientific fields such as cosmogenic dating. The nuclear transport codes are a common and accurate way to model the cosmic ray interaction in the atmosphere with minimal approximations. However, tracking all produced secondary particles in each event in the whole depth of the atmosphere and sampling many events to obtain the statistically meaningful results would be a computational challenge and disadvantageous from the point of view of time consumption. This paper presents a computational platform names ATMOS CORE based on pre-calculated databases coupled to physical models and computational methods. The fields of application concern the atmospheric cosmic-rays characterization as well as their effects on electronics systems, on the ambient dose for aircrews or the cosmogenic nuclide production for dating activities. Some comparisons between simulations and measurements are also presented and discussed.

Searches for atmospheric long-lived particles

Long-lived particles are predicted in extensions of the Standard Model that involve relatively light but very weakly interacting sectors. In this paper we consider the possibility that some of these particles are produced in atmospheric cosmic ray showers, and their decay intercepted by neutrino detectors such as IceCube or Super-Kamiokande. We present the methodology and evaluate the sensitivity of these searches in various scenarios, including extensions with heavy neutral leptons in models of massive neutrinos, models with an extra U(1) gauge symmetry, and a combination of both in a U(1)B−L model. Our results are shown as a function of the production rate and the lifetime of the corresponding long-lived particles.

History of Atmospheric Cosmic Ray Research at the National Bureau of Standards.

In the late 1930s, a team of physicists from the National Bureau of Standards (now the National Institute of Standards and Technology) published eight papers on the investigation of cosmic rays in the atmosphere. Payloads launched with weather balloons, also known as radiosondes, were equipped with sensors to measure temperature, relative humidity, pressure, and radiation dose. A battery-operated telemetry system was used to continuously transmit at 60 MHz to a base station. They measured the radiation dose profiles of cosmic radiation in the atmosphere up to 21 km. Calibration of the Geiger-Müller counters with a standard radium source allowed them to calculate a radiation dose rate at an altitude corresponding to 10 kPa that was 180 times the dose rate near sea level in Washington, DC. Ascents in Washington, DC (latitude 39 degrees) and Lima, Peru (near equator) allowed them to demonstrate the effects of Earth’s magnetic field on incident galactic cosmic rays; the dose rate in Peru was only half that in Washington, DC.

Update and New Features of NTHU Flight Dose Calculator: A Tool for Estimating Aviation Route Doses and Cumulative Spectra of Cosmic Rays in Atmosphere

This paper presents a major improvement in the NTHU Flight Dose Calculator, which not only extends its capabilities but also introduces three new features: the automatic batch analysis of multiple flights, route dose summation over all scheduled flights, and estimation of the cumulative spectra of cosmic rays along a flight path. Based on the results of extensive FLUKA simulations of atmospheric showers generated by galactic cosmic rays, a global database containing energy spectra and effective dose rates of neutrons, protons, muons, pions, electrons, positrons, photons, and heavy ions at various altitudes ranging from sea level up to 70 km was constructed and parameterized accounting for the dependences of altitude, geomagnetic cutoff rigidity, and solar modulation. The dose calculator was revised to accommodate and utilize the newly expanded database, which enables the estimation of aviation route doses and cumulative spectra of various radiation components by performing a series of interpolations and integration along a path. A program is a user-friendly tool for assessing radiation exposure of air travel due to galactic cosmic rays. The new features of the batch processing and route dose summation greatly facilitate studies of flight route effects and individual dose monitoring of aircrew. The cumulative spectra of various components can provide additional information for in-depth dosimetry analyses, designing experiments for measuring related quantities, and estimating single-event effects in avionics.

Dark matter astrophysical uncertainties and the neutrino floor

The search for weakly interacting massive particles (WIMPs) by direct detection faces an encroaching background due to coherent neutrino-nucleus scattering. For a given WIMP mass the cross section at which neutrinos constitute a dominant background is dependent on the uncertainty on the flux of each neutrino source from either the Sun, supernovae or atmospheric cosmic ray collisions. However there are also considerable uncertainties with regard to the astrophysical ingredients to the predicted WIMP signal. Uncertainties in the velocity of the Sun with respect to the Milky Way dark matter halo, the local density of WIMPs, and the shape of the local WIMP speed distribution all have an effect on the expected event rate in direct detection experiments and hence will change the region of the WIMP parameter space for which neutrinos are a significant background. In this work we extend the WIMP+neutrino analysis to account for the uncertainty in the astrophysics dependence of the WIMP signal. We show the effect of uncertainties on projected discovery limits with an emphasis on low WIMP masses (less than 10 GeV) when Solar neutrino backgrounds are most important. We find that accounting for astrophysical uncertainties changes the shape of the neutrino floor as a function of WIMP mass but also causes it to appear at cross sections up to an order of magnitude larger, extremely close to existing experimental limits - indicating that neutrino backgrounds will become an issue sooner than previously thought. We also explore how neutrinos hinder the estimation of WIMP parameters and how astrophysical uncertainties impact the discrimination of WIMPs and neutrinos with the use of their respective time dependencies.

Characterization of the atmospheric muon flux in IceCube

Muons produced in atmospheric cosmic ray showers account for the by far dominant part of the event yield in large-volume underground particle detectors. The IceCube detector, with an instrumented volume of about a cubic kilometer, has the potential to conduct unique investigations on atmospheric muons by exploiting the large collection area and the possibility to track particles over a long distance. Through detailed reconstruction of energy deposition along the tracks, the characteristics of muon bundles can be quantified, and individual particles of exceptionally high energy identified. The data can then be used to constrain the cosmic ray primary flux and the contribution to atmospheric lepton fluxes from prompt decays of short-lived hadrons.In this paper, techniques for the extraction of physical measurements from atmospheric muon events are described and first results are presented. The multiplicity spectrum of TeV muons in cosmic ray air showers for primaries in the energy range from the knee to the ankle is derived and found to be consistent with recent results from surface detectors. The single muon energy spectrum is determined up to PeV energies and shows a clear indication for the emergence of a distinct spectral component from prompt decays of short-lived hadrons. The magnitude of the prompt flux, which should include a substantial contribution from light vector meson di-muon decays, is consistent with current theoretical predictions.The variety of measurements and high event statistics can also be exploited for the evaluation of systematic effects. In the course of this study, internal inconsistencies in the zenith angle distribution of events were found which indicate the presence of an unexplained effect outside the currently applied range of detector systematics. The underlying cause could be related to the hadronic interaction models used to describe muon production in air showers.

Analytical Model for Estimating Terrestrial Cosmic Ray Fluxes Nearly Anytime and Anywhere in the World: Extension of PARMA/EXPACS.

By extending our previously established model, here we present a new model called “PHITS-based Analytical Radiation Model in the Atmosphere (PARMA) version 3.0,” which can instantaneously estimate terrestrial cosmic ray fluxes of neutrons, protons, ions with charge up to 28 (Ni), muons, electrons, positrons, and photons nearly anytime and anywhere in the Earth’s atmosphere. The model comprises numerous analytical functions with parameters whose numerical values were fitted to reproduce the results of the extensive air shower (EAS) simulation performed by Particle and Heavy Ion Transport code System (PHITS). The accuracy of the EAS simulation was well verified using various experimental data, while that of PARMA3.0 was confirmed by the high R 2 values of the fit. The models to be used for estimating radiation doses due to cosmic ray exposure, cosmic ray induced ionization rates, and count rates of neutron monitors were validated by investigating their capability to reproduce those quantities measured under various conditions. PARMA3.0 is available freely and is easy to use, as implemented in an open-access software program EXcel-based Program for Calculating Atmospheric Cosmic ray Spectrum (EXPACS). Because of these features, the new version of PARMA/EXPACS can be an important tool in various research fields such as geosciences, cosmic ray physics, and radiation research.

Multi-physics modelling contributions to investigate the atmospheric cosmic rays on the single event upset sensitivity along the scaling trend of CMOS technologies

Particles originating from primary cosmic radiation, which hit the Earth's atmosphere give rise to a complex field of secondary particles. These particles include neutrons, protons, muons, pions, etc. Since the 1980s it has been known that terrestrial cosmic rays can penetrate the natural shielding of buildings, equipment and circuit package and induce soft errors in integrated circuits. Recently, research has shown that commercial static random access memories are now so small and sufficiently sensitive that single event upsets (SEUs) may be induced from the electronic stopping of a proton. With continued advancements in process size, this downward trend in sensitivity is expected to continue. Then, muon soft errors have been predicted for nano-electronics. This paper describes the effects in the specific cases such as neutron-, proton- and muon-induced SEU observed in complementary metal-oxide semiconductor. The results will allow investigating the technology node sensitivity along the scaling trend.

Response of Water Cherenkov Detectors to Small Signals: a Case Study

Detailed studies of the response of the VATLY water Cherenkovdetector, a replica of those used in the ground array of the PierreAuger Observatory, are presented with emphasis on the response to lowamplitude signals. The method used is to detect decay electrons frommuons stopping in the water volume. Results include properties of the detection process as well as of the atmospheric cosmic ray flux.

Compact cosmic ray detector for unattended atmospheric ionization monitoring

Two vertical cosmic ray telescopes for atmospheric cosmic ray ionization event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B's event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located comparison of both telescopes exposed to atmospheric ionization showed a linear relationship between their event rates.

Imaging of high-Z material for nuclear contraband detection with a minimal prototype of a muon tomography station based on GEM detectors

Muon Tomography based on the measurement of multiple scattering of atmospheric cosmic ray muons in matter is a promising technique for detecting heavily shielded high-Z radioactive materials (U, Pu) in cargo or vehicles. The technique uses the deflection of cosmic ray muons in matter to perform tomographic imaging of high-Z material inside a probed volume. A Muon Tomography Station (MTS) requires position-sensitive detectors with high spatial resolution for optimal tracking of incoming and outgoing cosmic ray muons. Micro Pattern Gaseous Detector (MPGD) technologies such as Gas Electron Multiplier (GEM) detectors are excellent candidates for this application. We have built and operated a minimal MTS prototype based on 30cm \times 30cm GEM detectors for probing targets with various Z values inside the MTS volume. We report the first successful detection and imaging of medium-Z and high-Z targets of small volumes (~0.03 liters) using GEM-based Muon Tomography.

Study of the response of the cosmic ray muon flux to nonstationary processes in the Earth’s atmosphere

The results of the study of the correlation between dynamic atmospheric phenomena and cosmic ray muon flux variations are presented. The results of the long-term experiment on continuous measurements of spatioangular variations of the muon flux using the URAGAN muon hodoscope are considered. It was shown that the correlation between weather phenomena and changes in the angular distribution of the muon flux on the Earth’s surface are observed in 80% of cases, both in the general counting rate and in the zenith-azimuthal distribution of the muon flux intensity.

Comment on “‘Seed’ electrons from muon decay for runaway mechanism in the terrestrial gamma ray flash production,” by Gerson S. Paiva, Antonio C. Pavão, and Cristiano C. Bastos

Comment on “‘Seed’ electrons from muon decay for runaway mechanism in the terrestrial gamma ray flash production,” by Gerson S. Paiva, Antonio C. Pavão, and Cristiano C. Bastos