Detection Of Extensive Air Showers Research Articles

Radio-detection signature of high-energy cosmic rays by the CODALEMA experiment

Taking advantage of recent technical progress which has overcome some of the difficulties encountered in the 1960s in the radio detection of extensive air showers induced by ultra-high-energy cosmic rays (UHECR), a new experimental apparatus (CODALEMA) has been built and operated. We will present the characteristics of this device and the analysis techniques that have been developed for observing electrical transients associated with cosmic rays. We find a collection of events for which both time and arrival direction coincidences between particle and radio signals are observed. The counting rate corresponds to shower energies ⩾5×1016eV. The performance level which has been reached considerably enlarges the perspectives for studying UHECR events using radio detection.

The water Cherenkov detector array for studies of cosmic rays at the University of Puebla

We describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla ( 19 ∘ N , 90 ∘ W , 800 g / cm 2 ) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV, i.e., around the knee of the cosmic ray spectrum. The array consists of 3 water Cherenkov detectors of 1.86 m 2 cross-section and 12 liquid scintillator detectors of 1 m 2 distributed in a square grid with a detector spacing of 20 m over an area of 4000 m 2 . We discuss the calibration and stability of the array for both sets of detectors and report on preliminary measurements and reconstruction of the lateral distributions for the electromagnetic (EM) and muonic components of extensive air showers. We also discuss how the hybrid character of the array can be used to measure mass composition of the primary cosmic rays by estimating the relative contents of muons with respect to the EM component of extensive air showers. This facility is also used to train students interested in the field of cosmic rays.

Results from the Milagro Gamma-Ray Observatory

The Milagro Gamma-Ray Observatory, located at an altitude of 2630 m in the mountains of northern New Mexico, is a water-Cherenkov extensive air shower detector consisting of a 4800 m 2 covered pond instrumented with 723 PMTs. For improved sensitivity, 175 instrumented water tanks have recently been added surrounding the pond, covering an area of 40,000 m 2 . Milagro continuously observes the entire overhead sky, making it the ideal instrument to perform an all-sky search for TeV gamma-ray sources. Results from this survey are presented here, as well as a search for TeV emission from the galactic plane, and a search for transient emission above ∼100 GeV from gamma-ray bursts.

Results from the Puebla extensive air shower detector array

We describe the design and operation of the first stage of the EAS-UAP extensive air shower array, as a detector of very high energy cosmic rays ( E o > 10 14 eV). The array is located at the Campus of Puebla University and consists of 18 liquid scintillator detectors, with an active surface of 1 m 2 each and a detector spacing of 20 m in a square grid. In this report we discuss the stability and the calibration of the detector array, as derived from the 10 detectors in operation in the first stage. The main characteristics of the array allow us also to use it as an educational and training facility. First distributions of the arrival direction and the lateral shower srpead are also given.

Study of CR primaries and their cascades at E[formula omitted] = 10 ÷ 100 TeV through EAS-TOP and MACRO

A measurement of the lateral distribution of Cherenkov light in Extensive Air Showers (EAS) at E o = 10 ÷ 100 TeV and a study of the compatibility of the photon number spectra with the expectations from the direct measurements of p and α spectra and the Corsika-QGSJET propagation code in the atmosphere have been performed at the National Gran Sasso Laboratories by the EAS-TOP and MACRO arrays. The telescope array of EAS-TOP has been used as the Cherenkov light detector. The muon tracking system of MACRO in the deep underground Gran Sasso Laboratories ( E μ > 1.3 TeV) served as the EAS detector, including core localization and arrival direction.

Review of primary cosmic ray composition studies with underground detectors

The most important results on Cosmic Ray Composition obtained by the underground experiments at different depths are reviewed. Both the stand alone mode and the coincidence with extensive air shower (EAS) detectors are discussed.

Muons in extensive air showers: IV. Search for diffuse -ray emission in the regions 1014-1015 eV and above 1018 eV

Using data from the Haverah Park EAS (extensive air showers) detector array (GREX) and the associated muon detector an attempt is made to detect -ray primaries from the plane of the Galaxy. Muon cuts are made which should reduce background but retain the majority of any -ray primaries. Using the GREX array, a 40 m2 muon detector, and a data batch of ~5 × 106 EAS around 1015 eV, no significant -ray signal is seen. Specifically, the /particle ratio is less than 8.7 × 10-4. At energies above 1018 eV and using data from the earlier water Cerenkov arrays at Haverah Park with `muon-poor' cuts, again no signal is recognizable from the 1258 EAS data set. However, there is some evidence for Galactic plane enhancement of magnitude equal to that seen before, and this confirmation has value. In view of the changing nature of high-energy collisions at ultra-high energies it is just conceivable that the enhancement is due to -rays. The results and conclusions are thus consistent with other observations.

A water tank Cherenkov detector for very high-energy astroparticles

Extensive airshower detection is an important issue in current astrophysics endeavours. Surface arrays detectors are a common practice since they are easy to handle and have a 100% duty cycle. In this work we present an experimental study of the parameters relevant to the design of a water Cherenkov detector for high-energy airshowers. This detector is conceived as part of the surface array of the Pierre Auger Project, which is expected to be sensitive to ultra high-energy cosmic rays. In this paper we focus our attention in the geometry of the tank and its inner liner material, discussing pulse shapes and charge collections.

Cosmic thermal neutrino background: Can it be detected?

The detection of the Cosmic Thermal Neutrino Background (CTNB) would provide the “cleanest” evidence for the hot big bang model of the early Universe. I discuss some recent thoughts on the possibility of detecting the CTNB (especially if neutrinos have a small mass of ~ few eV) by looking for certain CTNB-induced features in the extremely high energy (E ≳ 1020 eV) cosmic neutrino spectrum that may become measurable in the future by some of the large-area extensive air-shower detectors being built for detecting extremely high energy cosmic rays.

Chers collègues, chers amis, chers abonnés

The ARGO-YBJ experiment, a full coverage extensive air shower (EAS) detector located at high altitude (4300 m a.s.l.) in Tibet, China, has smoothly taken data, with very high stability, since November 2007 to the beginning of 2013. The array consisted of a carpet of about 7000 m2 Resistive Plate Chambers (RPCs) operated in streamer mode and equipped with both digital and analog readout, providing the measurement of particle densities up to few particles per cm2. The unique detector features (full coverage, readout granularity, wide dynamic range, ..) and location (very high altitude) allowed a detailed study of the lateral density profile of charged particles at ground very close to the shower axis and its description by a proper lateral distribution function (LDF). In particular, the information collected in the first 10 m from the shower axis have been shown to provide a very effective tool for the determination of the shower development stage (“age”) in the energy range 50 TeV - 10 PeV. The sensitivity of the age parameter to the mass composition of primary Cosmic Rays is also discussed.

A Search for Ultra–High-Energy Gamma-Ray Emission from Five Supernova Remnants

The majority of the cosmic rays in our Galaxy with energies in the range of ~1010-1014 eV are thought to be accelerated in supernova remnants (SNRs). Measurements of SNR gamma-ray spectra in this energy region could support or contradict this concept. The Energetic Gamma-Ray Experiment Telescope (EGRET) collaboration has reported six sources of gamma rays above 108 eV whose coordinates are coincident with SNRs. Five of these sources are within the field of view of the CYGNUS extensive air shower detector. A search of the CYGNUS data set reveals no evidence of gamma-ray emission at energies ~1014 eV for these five SNRs. The flux upper limits from the CYGNUS data are compared to the lower energy fluxes measured with the EGRET detector using Drury, Aharonian, & Volk's recent model of gamma-ray production in the shocks of SNRs. The results suggest one or more of the following: (1) the gamma-ray spectra for these five SNRs soften by about 1014 eV, (2) the integral gamma-ray spectra of the SNRs are steeper than about E-1.3, or (3) most of the gamma rays detected with the EGRET instrument for each SNR are not produced in the SNR's shock but are produced at some other site (such as a pulsar).

A Northern Sky Survey for Astrophysical Point Sources of 100 TeV Gamma Radiation

The CASA-MIA experiment is a very large extensive air shower detector with good angular resolution. A part of this instrument has been used to search the visible sky for astrophysical point sources of gamma rays with energies ≥100 TeV. Approximately 90% of the charged cosmic-ray background is rejected through measurement of the muon content of the showers. Stringent limits are placed on the flux of 100 TeV gamma rays from previously unknown point sources across a large fraction of the northern sky. The complete instrument, with significantly greater sensitivity, has been in operation for more than a year

Observation of shadowing of ultrahigh-energy cosmic rays by the Moon and the Sun.

Data from an extensive air shower detector of ultrahigh-energy cosmic rays shows shadowing of the cosmic-ray flux by the Moon and the Sun with significance of 4.9 standard deviations. This is the first observation of such shadowing. The effect has been used to determine that the angular resolution of the detector is 0.75{degree} {sub {minus}0.90{degree}}{sup +0.13{degree}}.

Time dispersion of muons in EAS

Describes the results and conclusions from an experiment set up to measure the time spread of muons in extensive air showers (EAS) detected at the Haverah Park EAS detector array, UK. The pulse risetimes (T70) from 10% to 70% amplitude of the responses from 3*10 m2 muon detectors are studied, and the anomalous pulse structure is investigated. The mean T70 is studied as a function of shower size, zenith angle and core distance and its dependence on shower size is related to the elongation length of the EAS. Fluctuations in T70 are studied as a method of yielding the mass composition of the primary particles. The measured fluctuations in T70 are related to fluctuations in the depth of the electromagnetic cascade maximum. The results yield the same value for both the elongation rate and the fluctuation in the depth of maximum sigma (Xm) of 58(+or-23) g cm-2. The results are consistent with simulation studies that assume protons are still the dominant component of cosmic rays in the energy range 1017 to 1018 eV.

A new method to identify muons in an extensive air shower array

Using position-sensitive detectors for the detection of extensive air showers presents a new possibility to identify muons by exploiting the electromagnetic interactions in a thin, high-Z absorber. The fact that these detectors track each charged particle allows the use of a thin layer of material as the muon identifier. The authors' Monte Carlo studies indicate that by using 2.6 radiation lengths of high-Z absorber as a muon detector, a simple algorithm will correctly identify 98% of electrons as electrons and 96% of muons as muons for a cut-off angle of 100 mrad.

A study of the pulse profiles from EAS nuon scintillator detectors

A storage oscilloscope recording system has been operated at the Haverah Park Extensive Air Shower detector array in order to investigate the time-spread of muons in EAS. The recorded data is categorized to pulse shape. About 8% of the recorded pulses show a distinct structure effect which is not explainable in terms of instrumental sampling or currently predicted EAS effects.

The mean lateral density distribution of muons in extensive air showers detected at Haverah Park

Presents the results and conclusions from an experiment carried out between 1969 and 1973 at the Haverah Park cosmic ray extensive air shower detector array near Harrogate, Yorkshire. The detector consisted of 12m2 of shielded neon flash tubes sensitive to muons of energy greater than 300 sec theta MeV. The detector was situated at the centre of the EAS array and its response to showers of primary energy 1017 eV<or approximately=Ep<or approximately=1019 eV, with zenith angles up to 60 degrees has been studied. The analysis has been restricted to those showers in which the distance (R) from the core of the shower to the detector was in the interval 100<R<1000 m. The results are compared with model calculations and a number of conclusions drawn.