Abstract
Above 10\(^{15}\) eV, the CR flux drops below a few tens of particles per m\(^2\)-year. It is no longer possible to detect the incident particles above the atmosphere before they interact. Direct experiments (characterized by a small geometrical factor \(A\cdot \varDelta \varOmega \) [cm\(^2\) sr]) must be replaced by ground-based instruments that cover up to several thousands of km\(^2\), the extensive air shower (EAS) arrays. They use a completely different approach to CR measurements, started by pioneering experiments soon after World War II by Auger, Kohlhörster and Rossi. The EAS arrays are in most cases large area and long duration experiments studying, as accurately as possible, the nature, flux, mass, direction of primary CRs up to the highest energies. Air showers are initiated by primary CRs, through the interaction with a nucleus in the atmosphere. In addition to the hadronic component the decays of short-lived hadrons lead to a shower of particles: photons, electrons, and positrons constitute the electromagnetic (EM) component; muons and neutrinos constitute the penetrating component. All these particles travel at the speed of light in the atmosphere approximately along the direction of the primary CR. High energy primary \(\gamma \)-rays induce an almost pure EM cascade. In Sect. 4.3 we present a simple model for the EM cascade initiated by a \(\gamma \)-ray, which can be mathematically treated using differential transport equations of \(e^\pm \) and \(\gamma \) in the atmosphere. Some simple features, as derived from approximate solutions of the cascade equations, are presented. The cascades initiated by primary CR protons or nuclei have additional features. They are also characterized by large event-to-event fluctuations. Their description is today achieved using full Monte Carlo simulations, which follow the details of the development of the EM and muonic components. It is interesting, however, to obtain (Sect. 4.4) a first-order estimate of the quantities, which can be measured by experiments both for the muonic and the EM components. In the first sections of the chapter, we enumerate the main showers features (denoted as SF1, SF2,..., SF12)) which characterize EM and muonic component of the cascade initiated by \(\gamma \)-rays, protons, and heavier nuclei. These characteristics are confirmed by detailed Monte Carlo simulations of air showers in the atmosphere (Sect. 4.5), which are used by the experiments to interpret their observations. EAS arrays are installed on ground and are sometimes referred to as indirect detection experiments. Modern shower arrays employ complementary techniques (Sect. 4.6) such as scintillators, air Cherenkov detectors, etc. to measure simultaneously as many shower parameters as possible, in order to reduce the model dependence in the energy and mass number \(A\) determination. The features of the EM and muonic cascades will be used in Sects. 4.8, 4.9 and 4.10 to illustrate how indirect experiments can derive the CR flux and properties in the energy region around the knee of CRs.
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Notes
- 1.
For historical reasons, photons with energy in the MeV scale and beyond are called \(\gamma \)-rays.
- 2.
Before the LHC physics runs, someone expressed concerns over the safety, and attempted to halt the beginning of the experiments through petitions to the US and European Courts. These opponents asserted that the LHC experiments have the potential to create micro black holes that could grow in mass or release dangerous radiation leading to doomsday scenarios, such as the destruction of the Earth. Any doomsday scenario at the LHC was ruled out before starting of the physics runs simply noting that the physical conditions and events created in the LHC experiments occur naturally and routinely in the Universe without hazardous consequences. In particular, ultra high energy CRs that are impacting on Earth with energies considerably higher than those reached in any man-made collider have never destroyed the Earth!
- 3.
Two solutions exist denoted as Approximation A when the electron excitation/ionization losses are neglected and Approximation B when they are included.
- 4.
A charged particle traversing a medium is deflected by many small-angle scatters. This deflection is due to the superposition of many Coulomb scatterings from individual nuclei, and hence the effect is called multiple Coulomb scattering. The Coulomb scattering distribution is well represented by a Gaussian distribution. At larger angles the distribution shows larger tails and the behavior is more similar to that of Rutherford scattering.
- 5.
The \(\varGamma \) function is an extension for positive real numbers of the factorial.
- 6.
The quantity \( n_\mathrm{ch}\) is more easily measured in accelerator experiments than \(n_h\).
- 7.
Analog-to-Digital Converters (ADC) convert the height or the integral of an electronic signal into a digital number. For instance, the height of a signal between 0 and 5 V may be converted by a 10-bit ADC into a number between 0 and 2\(^{10}-1 = 1{,}023\). Flash-ADCs are very fast compared to other ADC types, so a single flash-ADC can be used to analyze various channels in sequence, or to analyze in a time-sequence the development of a pulse, functioning in this way as a Waveform Analyzer (WFA).
References
M. Aglietta et al., (EAS-TOP Coll.) The EAS size spectrum and the cosmic ray energy spectrum in the region \(10^{15}-10^{16}\) eV. Astropart. Phys. 10, 119 (1999)
S.P. Ahlen et al., (MACRO Coll.). Arrival time distributions of very high energy cosmic ray muons in MACRO. Nucl. Phys. B370, 432–444 (1992)
J. Alvarez-Muniz, R. Engel, T.K. Gaisser, J.A. Ortiz, T. Stanev, Hybrid simulations of extensive air showers. Phys. Rev. D66, 033011 (2002)
L. Anchordoqui et al., High energy physics in the atmosphere: phenomenology of cosmic ray air showers. Ann. Phys. 314, 145–207 (2004)
T. Antoni et al., (KASCADE coll). The cosmic-ray experiment KASCADE. Nucl. Instr. Methods A513, 490–510 (2003)
T. Antoni et al., KASCADE measurements of energy spectra for elemental groups of cosmic rays: results and open problems. Astropart. Phys. 24, 1–25 (2005)
W.D. Apel et al., Energy spectra of elemental groups of cosmic rays: update on the KASCADE unfolding analysis. Astropart. Phys. 31, 86–91 (2009)
W.D. Apel et al., Kneelike structure in the spectrum of the heavy component of cosmic rays observed with KASCADE-Grande. Phys. Rev. Lett. 107, 171104 (2011)
W.D. Apel et al., Time structure of the EAS electron and muon components measured by the KASCADE-Grande experiment. Astropart. Phys. 29, 317–330 (2008)
J. Blümer, R. Engel, J.R. Hörandel, Cosmic rays from the knee to the highest energies. Prog. Part. Nucl. Phys. 63, 293–338 (2009)
S. Braibant, G. Giacomelli, M. Spurio, Particle and fundamental interactions, (Springer, 2011), ISBN 978-9400724631
G. Cowan, Statistical Data Analysis, (Oxford University Press, 1998). ISBN: 978-0198501558
S. Eidelman et al., (Particle data group). Review of particle physics. Phys. Lett. B 592, 1 (2004)
R. Engel, D. Heck, T. Pierog, Extensive air showers and hadronic interactions at high energy. Annu. Rev. Nucl. Part. Sci. 61, 467–489 (2011)
T.K. Gaisser, Cosmic Rays and Particle Physics (Cambridge University Press, Cambridge, 1991)
A. Garyaka et al., Rigidity-dependent cosmic ray energy spectra in the knee region obtained with the GAMMA experiment. Astropart. Phys. 28, 169–181 (2007)
K. Greisen, Cosmic ray showers. Ann. Rev. Nucl. Part. Sci. 10, 63–108 (1960)
P.K.F. Grieder, Extensive Air Showers, (Springer ,2010), ISBN 978-3-540-76940-8
D. Heck, CORSIKA: A Monte Carlo Code to Simulate Extensive Air Showers. Forschungszentrum Karlsruhe FZKA 6019 (1998)
W. Heitler, Quantum Theory of Radiation (Oxford University Press, Oxford, 1944)
J.R. Hörandel, On the knee in the energy spectrum of cosmic rays. Astropart. Phys. 19, 193–220 (2003)
J. Hörandel, Cosmic rays from the knee to the second knee: 10\(^{14}\)–10\(^{18}\) eV. Mod. Phys. Lett. A 22, 1533–1552 (2007)
K. Kamata, J. Nishimura, Progr. Theor. Phys. 6, 93 (1958)
K.H. Kampert, M. Unger, Measurements of the cosmic ray composition with air shower experiments. Astropart. Phys. 35, 660 (2012)
K.-H. Kampert, A.A. Watson, Extensive air showers and ultra high-energy cosmic rays: a historical review. Eur. Phys. J. H 37, 359–412 (2012)
J. Knapp, D. Heck, Extensive air shower simulation with CORSIKA: A User’s Manual. Kernforschungszentrum Karlsruhe KfK 5196 B, 1993; for an up to date version see http://wwwik.fzk.de/CORSIKA/
A. Letessier-Selvon, T. Stanev, Ultrahigh energy cosmic rays. Rev. Mod. Phys. 83, 907 (2011)
P. Lipari, The concepts of age and universality in cosmic ray showers. Phys. Rev. D 79, 063001 (2009)
J. Matthews, A Heitler model of extensive air showers. Astropart. Phys. 22, 387–397 (2005)
M. Nagano, A.A. Watson, Observations and implications of the ultrahigh-energy cosmic rays. Rev. Mod. Phys. 72(3), 689–732 (2000)
J. Nishimura, Handbuch der Physik 46(2), 1 (1965)
B. Rossi, K. Greisen, Cosmic ray theory. Rev. Mod. Phys. 13, 240–309 (1941)
T. Stanev, High Energy Cosmic Rays, (Springer, 2010), ISBN 9783540851486
S.P. Swordy et al., The composition of cosmic rays at the knee. Astropart. Phys. 18, 129–150 (2002)
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Spurio, M. (2015). Indirect Cosmic Rays Detection: Particle Showers in the Atmosphere. In: Particles and Astrophysics. Astronomy and Astrophysics Library. Springer, Cham. https://doi.org/10.1007/978-3-319-08051-2_4
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