Cosmic-ray Showers Research Articles

Signal Convolution of Wide FOV Cherenkov Telescope

The operation of a wide field-of-view (WFOV) Cherenkov telescope is described. Detection of extensive air showers (EAS) of cosmic rays (CR) is based on the coincidence with signals from the Yakutsk array. The data acquisition system (DAQ) of the telescope yields signals connected with EAS development parameters: shower age and position of shower maximum in the atmosphere. Here we describe the application of digital signal processing for reconstruction of Cherenkov radiation signals induced by air showers.

Local shower age and segmented slope parameters of lateral density distributions of cosmic ray shower particles

The paper describes lateral density distributions of electrons and muons of cosmic ray extensive air showers (EAS) in the energy regime of the KASCADE experiment. Potential EAS observables are extracted while some suitable lateral distribution functions are introduced to describe these lateral density distributions of simulated/observed cosmic ray showers. Mass-sensitivity of these parameters are demonstrated particularly for the KASCADE electron and muon distributions data. Our studies indicate that the KASCADE data favours an idea of gradual change of cosmic ray mass composition from lighter concentration to heavier concentration in terms of these parameters.

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.

Quantifying the Effect of Cosmic Ray Showers on the X-IFU Energy Resolution

The X-ray Integral Field Unit (X-IFU) will operate an array of more than 3000 Transition Edge Sensor pixels at 90 mK with an unprecedented energy resolution of 2.5 eV at 7 keV. In space, primary cosmic rays and secondary particles produced in the instrument structure will continuously deposit energy on the detector wafer and induce fluctuations on the pixels’ thermal bath. We have investigated through simulations of the X-IFU readout chain how these fluctuations eventually influence the energy measurement of X-ray photons. Realistic timelines of thermal bath fluctuations at different positions in the array are generated as a function of a thermal model and the expected distribution of the deposited energy of the charged particles. These are then used to model the TES response to these thermal perturbations and their influence on the onboard energy reconstruction process. Overall, we show that with adequate heatsinking, the main energy resolution degradation effect remains minimal and within the associated resolution allocation of 0.2 eV. We further study how a dedicated triggering algorithm could be put in place to flag the rarer large thermal events.

A TLD-Microdosimeter for aerospace usage: Results relevant to airline pilots undertook long-haul intercontinental flights during March–May 2017

During high altitude long haul flights pilots, cabin crew and passengers are exposed to enhanced level of radiation originating from cosmic ray showers (CRS), produced via the interaction of very high-energy (~GeV) primary protons with the air molecules in Earth's atmosphere. The CRS are composed of energetic particles of diverse species, i.e. neutrons, protons, electrons, muons, pions and photons. Furthermore, the magnitude of aircrew radiation exposure depends on flight altitude and duration, geographical location (latitude), geomagnetic conditions and solar activity (modulation) status. In 1990 the International Commission on Radiological Protection (ICRP) classified airline crewmembers as “radiation workers”. A miniature passive microdosimeter (LiBe-14) based on LiF (TLD700) and Beryllium Oxide (BeO) thermoluminescence dosimeter chips emulating a large volume gas-filled Tissue Equivalent Proportional Counter (TEPC) was developed by one of the authors (BM). The LiBe-14 was deployed to assess the integrated ambient dose equivalent of two commercial pilots on long haul intercontinental flights during March–May 2017. The accumulated dose equivalents of 1st (38 y, Female, 148 total block hours) and 2nd (29 y, Male, 149 total block hours) pilots were evaluated to be 565 μSv ± 105 μSv and 738 μSv ± 137 μSv, respectively. The results agreed well within ±20% of simulated data evaluated using the well-known EPCARD (European Program Package for the Calculation of Aviation Route Doses) aviation dosimetry code. The implementation of LiBe-14 Microdosimeter in routine long haul, high-altitude commercial flights for the estimation of dose equivalent, average LET and quality factor relevant to impinging cosmic radiation is recommended.

Reconstructing the cosmic-ray energy from the radio signal measured in one single station

Short radio pulses can be measured from showers of both high-energy cosmic rays and neutrinos. While commonly several antenna stations are needed to reconstruct the energy of an air shower, we describe a novel method that relies on the radio signal measured in one antenna station only. Exploiting a broad frequency bandwidth of 80−300 MHz, we obtain a statistical energy resolution of better than 15% on a realistic Monte Carlo set. This method is both a step towards energy reconstruction from the radio signal of neutrino induced showers, as well as a promising tool for cosmic-ray radio arrays. Especially for hybrid arrays where the air shower geometry is provided by an independent detector, this method provides a precise handle on the energy of the shower even with a sparse array.

Stability of gluonic systems with multiple soft interactions

In this paper, we investigate the stability properties of soft gluons in SIBYLL 2.1 with reference to its original version 1.7 that corresponds to hadronic hard interactions. In order to investigate the stability structures, we classify the regions of the gluon density fluctuations in its double leading logarithmic approximation and its equivalent description as the fractional power law. In the parameter space of initial transverse momentum $Q$ and QCD renormalization scale $L$ that correspond to extensive air showers of cosmic rays, we have categorized the surface of parameters over which the proton is stable. We further discuss the nature of local and global correlations and stability properties where the concerning statistical basis yields a stable system or undergoes a geometric phase transition. Finally, we give a phenomenological understanding towards the stability of soft interactions, Pomeron particle productions in minijet model, string fragmentation and verify our result corresponding to the experiments - CDF, P238, UAS, GEUS and UA4 collaborations.

Observation of Ground-level Enhancement Across Canada's Fixed Point Surveillance Network During the 20 January 2005 Solar Event.

This paper presents the count rate enhancement observed across Canada's Fixed Point Surveillance network during the solar event on 20 January 2005 and explores the feasibility and value of applying the Fixed Point Surveillance network's long-term and continuous observations for space weather monitoring. The count rate, recorded in the high-energy channel of RS250 sodium iodide detectors, reflects the detector's response to muonic and electromagnetic components of the cosmic ray shower. During the event peak time, simultaneous count rate increases have been observed across many Fixed Point Surveillance network stations at enhancements varying from 10% to 18%, 12- to 15-fold less than relative increases in neutron detector observations.

Site analysis in the Argentinean Andean region for the placement of astrophysical observatories and solar photovoltaic power plants. The case of the “Leoncito 2” site

After a detailed search for possible sites where to place astrophysical facilities in Argentinean Andean region, a location labeled as LEO 2 (31°24′22″ S, 69°29′32″ W, 1630 masl) is proposed. It is placed near the largest Astronomical Observatory of Argentina: Complejo AStronómico El LEOncito (CASLEO). Its advantages are: a good altitude to detect the maximum development of cosmic ray showers, high spectral transmittance to UV and visible ranges, very low aerosol content (mean particle concentration measured at ground with an optical particle counter PM2.5 = 1.52 µg m−3 and PM>2.5 = 6.83 µg m−3, mean Aerosol Optical Depth at 550 nm = 0.027 (measured from space using the SeaWiFS instrument on board of the SeaStar NASA satellite). A local meteorological analysis was done, using data measured in situ, which shows a typical desertic site with the following mean annual (std. dev.) values:mean annual temperature 18.93 (7.66) °C, mean annual relative humidity 28.76 (20.55)%, low/ moderate mean annual average wind speed 11.63 (8.78) km/h, low mean water content (0.73 cm) and rather low mean cloud coverage fraction (cloud coverage fraction): 0.29 (0.02) (for the period 2003–2016 from Aqua/NASA satellite MODIS device) and 0.25 (0.01) (for the period 2000–2016, Terra/NASA satellite MODIS device). Concerning the conditions for the placement of photovoltaic solar power plants, some positive aspects that can be remarked are a large rather flat available surface (336 km2) with very good levels of annual mean horizontal solar irradiation: Global (2334 kWh m−2per year), Direct (3127 kWh m−2 per year) and Diffuse (394 kWh m−2 per year). Optimum angle to place solar panels at this site is determined and the global tilted solar irradiation is calculated (2689 kWh m−2 per year). In comparison with an African (Ouarzazate, Morocco) and Asian (Dubai) sites, the analysed site present better annual irradiation levels being the Global horizontal irradiation at the Argentinean site 8.1% and 10.3% higher than those calculated for the African and Asian site respectively. Also, a comparison is made of different solar cells (monocrystalline Si, polycrystalline Si and perovskite), through the calculation of the generated photocurrent (mean produced solar photovoltaic current per unit cell surface), considering the atmospheric and solar radiation parameters found for the studied site. We thus conclude that the proposed site in the Andes range is well suited for the placement of Astrophysical facilities, as well as Photovoltaic solar power plants.

The EUSO-SPB2 mission

EUSO-SPB2 is a second generation Extreme Universe Space Observatory (EUSO) on a Super-Pressure Balloon (SPB). The mission broadens the scientific objectives of the JEM-EUSO program and constitutes the first step toward the study of neutrino signals from the high atmosphere and space.The EUSO-SPB2 science payload will be equipped with two detectors designed for a long duration mission. One is a fluorescence telescope developed to detect Ultra High Energy Cosmic Rays via the UV fluorescence emission of the particle showers generated in the atmosphere. The other telescope will measure Cherenkov light emission from showers of lower energy cosmic rays to study and measure the background contribution for detecting cosmogenic neutrinos. These specific techniques and detection methods are performed in light of the realization of the Probe of Extreme Multi Messenger Astronomy (POEMMA), a space mission, currently under NASA-funded conceptual design studies. The EUSO-SPB2 mission has been approved by NASA and foreseen to be launched in 2022.In this paper we will give a description of the payload, including details on the detection techniques and the telescopes design.

Sterile neutrino origin for the upward directed cosmic ray showers detected by ANITA

The ANITA balloon experiment has recently observed several ~EeV cascade events at an angle below the horizon that renders any Standard Model (SM) interpretation unlikely as the Earth is significantly opaque to all SM particles at such energies. In this paper, we study a sterile neutrino interpretation of these events, calculating the angular acceptance of cascades and the relative sensitivities of several experiments to a cascade initiated by an EeV sterile neutrino. We find that ANITA is uniquely sensitive to this type of upward directed cascade signal over a wide portion of the sky and from the direction of the two observed events has a transient acceptance roughly equivalent to that of the IceCube experiment.

EAS detection by wide-angle cherenkov telescopes at the Yakutsk array

A proposed new method for measuring the Cherenkov light from extensive air showers (EAS) of cosmic rays (CR), which allows to determine not only the primary particle energy and angle of arrival, but also the parameters of the shower in the atmosphere - the maximum depth and “age”. For measurements, it is proposed to use Cherenkov light produced by EAS in a ground network of wide-angle telescopes, which are separated from each other by a distance 100-300 m depending on the total number of telescopes operating in coincidence, acting autonomously, or includes a detector of the charged components, radio waves, etc. as part of the EAS. The energy measurement and CR angle of arrival, data on the depth of the maximum and the associated mass of the primary particle generating the EAS is particularly important in the study of galactic cosmic rays for E> 1014 eV, where currently there are no direct measurements of the maximum depth of the EAS.

The hadronic interaction model Sibyll 2.3c and muon production in extensive air-showers

One of the applications of the hadronic interaction model Sibyll is the simulation of extensive air showers of ultra-high energy cosmic rays. In recent years it has become more and more clear that simulations do not agree with measurements when it comes to observables related to muons in air showers. We discuss the processes in Sibyll that are directly related to muon production in extensive air showers and describe their relation to shower observables.

Recent results from the KASCADE-Grande data analysis

KASCADE, together with its extension KASCADE-Grande measured individual air showers of cosmic rays in the primary energy range of 100 TeV to 1 EeV. The data collection was fully completed at the end of 2013 and the experiment was dismantled. However, the data analysis is still in progress. Recently, we published a new result on upper limits to the flux of ultra-high energy gamma rays, which set constraints on some fundamental astrophysical models. We also use the data to investigate the validity of the new hadronic interactions models like SIBYLL version 2.3c or EPOS-LHC. In addition, we updated and improved the webbased platform of the KASCADE Cosmic Ray Data Centre (KCDC), where now the data from KASCADE and KASCADE-Grande of more than 20 years measurements is available, including corresponding Monte-Carlo simulated events based on three different hadronic interaction models. In this contribution, recent results from KASCADE-Grande and the update of KCDC is briefly discussed.

Determining atmospheric electric fields through radio emission from air showers

During thunderstorm conditions the radio footprint (intensity as well as polarization) of cosmic ray showers deviates strongly from those measured during fair weather. We have been able to interpret this pattern in terms of atmospheric electric fields. We see that even when there is no thunderstorm activity within 100 km distance within an hour of the event, the radio footprint may be strongly affected

Performance optimization of the air shower simulation program for the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA), currently under construction, is the next-generation instrument in the field of very high energy gamma-ray astronomy. The first data are expected by the end of 2018, while the scientific operations will start in 2022 for a duration of about 30 years. In order to characterize the instrument response to the Cherenkov light emitted when cosmic ray showers develop in the atmosphere, detailed Monte Carlo simulations will be regularly performed in parallel to CTA operation. The estimated CPU time associated to these simulations is very high, of the order of 200 millions HS06 hours per year. Reducing the CPU time devoted to simulations would allow either to reduce infrastructure cost or to better cover the large phase space. In this paper, we focus on the main computing step (70% of the whole CPU time) implemented in the CORSIKA program, and specifically on the mod-ule responsible for the propagation of Cherenkov photons in the atmosphere. We present our preliminary studies about different options of code optimization, with a particular focus on vectorization facilities (SIMD instructions). Our proposals take care, as automatically as possible, of the hardware portability constraints introduced by the grid computing environment that hosts these simulations. Performance evaluation in terms of running-time and accuracy is provided.

Average shape of longitudinal shower profiles measured at the Pierre Auger Observatory

The average profiles of cosmic ray shower development as a function of atmospheric depth are measured for the first time with the Fluorescence Detectors at the Pierre Auger Observatory. The profile shapes are well reproduced by the Gaisser-Hillas parametrization at the 1% level in a 500 g/cm2 interval around the shower maximum, for cosmic rays with log(E/eV) > 17.8. The results are quantified with two shape parameters, measured as a function of energy. The average profiles carry information on the primary cosmic ray and its high energy hadronic interactions. The shape parameters predicted by the commonly used models are compatible with the measured ones within experimental uncertainties. Those uncertainties are dominated by systematics which, at present, prevent a detailed composition analysis.

A Scintillator and Radio Enhancement of the IceCube Surface Detector Array

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.

Measurement of the Background Gamma Dose Rates in Houston, Texas: A Descriptive Summary of an Undergraduate Research Mentored Project Performed by Students Underrepresented in the Health Physics Profession.

Natural background radiations include cosmic, terrestrial, and medical sources. Cosmic radiation is mostly shielded by the magnetic field of the Earth; however, those that penetrate can produce nuclear interactions within the Earth's atmosphere yielding cosmic ray showers. Terrestrial and medical sources of radioactivity are typically identified through radionuclide-specific decay signatures. Medical sources of radiation mainly result from diagnostic x rays, which attenuate into the environment. These x rays also contribute slightly to background radiation. The purpose of this study was to have students involved with the Texas Southern University (TSU) health physics program measure and report background gamma dose rates in Houston, Texas, using the Canberra InSpector 1000 Digital Hand-Held Multichannel Analyzer. The results were compared with the average gamma dose rate on Earth. Of note, TSU is one of the largest historically black colleges and universities (HBCUs) in the nation and currently boasts the only undergraduate health physics program in Houston. Targeted locations were selected within the I-610 loop of Houston covering an area of approximately 100 km. Measurements were performed at nine locations and verified by GPS latitude and longitude coordinates. The dose rate was measured over a 100 m area at each location, while spectral analysis was simultaneously performed for natural gamma-emitters. Our results suggest the dose rate averaged over all geographical locations in this study was 0.114 ± 0.001 μSv h and thus, consistent with most literature. The only radionuclide identified in the spectra in all measurements was K due to the limited energy resolution of the InSpector 1000.

Particle production in ultrastrong-coupling waveguide QED

Understanding large-scale interacting quantum matter requires dealing with the huge number of quanta that are produced by scattering even a few particles against a complex quantum object. Prominent examples are found from high energy cosmic ray showers to the optical or electrical driving of degenerate Fermi gases. We tackle this challenge in the context of many-body quantum optics, as motivated by the recent developments of circuit quantum electrodynamics at ultrastrong coupling. The issue of particle production is addressed quantitatively with a simple yet powerful concept rooted in the quantum superposition principle. This key idea is illustrated by the study of multi-photon emission from a single two-level artificial atom coupled to a high impedance waveguide. We find surprisingly that the off-resonant inelastic emission lineshape is dominated by broadband particle production, due to the large phase space associated with contributions that do not conserve the number of excitations. Such frequency conversion processes produce striking signatures in time correlation measurements, which can be tested experimentally in quantum waveguides. These ideas open new directions for the simulation of a variety of physical systems, from polaron dynamics in solids to complex superconducting quantum architectures.