The KASCADE-Grande experiment Apel, W.D.; Arteaga, J.C.; Badea, A.F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2010, Letnik:
620, Številka:
2
Journal Article
Recenzirano
KASCADE-Grande is the enlargement of the KASCADE extensive air shower detector, realized to expand the cosmic ray studies from the previous 10
14–10
17
eV primary energy range to 10
18
eV. This is ...performed by extending the area covered by the KASCADE electromagnetic array from 200×200 to 700×700
m
2 by means of 37 scintillator detector stations of 10
m
2 area each. This new array is named Grande and provides measurements of the all-charged particle component of extensive air showers (
N
ch
), while the original KASCADE array particularly provides information on the muon content
(
N
μ
)
. Additional dense compact detector set-ups being sensitive to energetic hadrons and muons are used for data consistency checks and calibration purposes. The performance of the Grande array and its integration into the entire experimental complex is discussed. It is demonstrated that the overall observable resolutions are adequate to meet the physical requirements of the measurements, i.e. primary energy spectrum and elemental composition studies in the primary cosmic ray energy range of 10
16–10
18
eV.
A composition analysis of KASCADE air shower data is performed by means of unfolding the two-dimensional frequency spectrum of electron and muon numbers. Aim of the analysis is the determination of ...energy spectra for elemental groups representing the chemical composition of primary cosmic rays. Since such an analysis depends crucially on simulations of air showers the two different hadronic interaction models QGSJet and SIBYLL are used for their generation. The resulting primary energy spectra show that the knee in the all particle spectrum is due to a steepening of the spectra of light elements but, also, that neither of the two simulation sets is able to describe the measured data consistently over the whole energy range with discrepancies appearing in different energy regions.
We present the results of the search for large-scale anisotropies in the arrival directions of cosmic rays performed with the KASCADE-Grande experiment at energies higher than eV. To eliminate ...spurious anisotropies due to atmospheric or instrumental effects we apply the east-west method. We show, using the solar time distribution of the number of counts, that this technique allow us to remove correctly the count variations not associated to real anisotropies. By applying the east-west method we obtain the distribution of number of counts in intervals of 20 minutes of sidereal time. This distribution is then analyzed by searching for a dipole component; the significance of the amplitude of the first harmonic is 3.5 , therefore, we derive its upper limit. The phase of the first harmonic is determined with an error of a few hours and is in agreement with the measurements obtained in the 1014 < E < 2 × 1015 eV energy range by the EAS-TOP, IceCube, and IceTop experiments. This supports the hypothesis of a change of the phase of the first harmonic at energies greater than ∼2 × 1014 eV.
The KASCADE-Grande air shower experiment 1 consists of, among others, a large scintillator array for measurements of charged particles, Nch, and of an array of shielded scintillation counters used ...for muon counting, Nμ. KASCADE-Grande is optimized for cosmic ray measurements in the energy range 10PeV to about 2000PeV, where exploring the composition is of fundamental importance for understanding the transition from galactic to extragalactic origin of cosmic rays. Following earlier studies of the all-particle and the elemental spectra reconstructed in the knee energy range from KASCADE data 2, we have now extended these measurements to beyond 200PeV. By analysing the two-dimensional shower size spectrum Nch vs. Nμ for nearly vertical events, we reconstruct the energy spectra of different mass groups by means of unfolding methods over an energy range where the detector is fully efficient. The procedure and its results, which are derived based on the hadronic interaction model QGSJET-II-02 and which yield a strong indication for a dominance of heavy mass groups in the covered energy range and for a knee-like structure in the iron spectrum at around 80PeV, are presented. This confirms and further refines the results obtained by other analyses of KASCADE-Grande data, which already gave evidence for a knee-like structure in the heavy component of cosmic rays at about 80PeV 3.
•The effective muon attenuation and absorption lengths of air showers are investigated.•Air shower data of the KASCADE-Grande observatory is analyzed.•Predictions of the models SIBYLL 2.1, EPOS-LHC, ...QGSJET-II-02 and -04 are tested.•The studied models fail to describe consistently the attenuation of the muon data.
The evolution of the muon content of very high energy air showers (EAS) in the atmosphere is investigated with data of the KASCADE-Grande observatory. For this purpose, the muon attenuation length in the atmosphere is obtained to Λμ=1256±85−232+229(syst)g/cm2 from the experimental data for shower energies between 1016.3 and 1017.0 eV. Comparison of this quantity with predictions of the high-energy hadronic interaction models QGSJET-II-02, SIBYLL 2.1, QGSJET-II-04 and EPOS-LHC reveals that the attenuation of the muon content of measured EAS in the atmosphere is lower than predicted. Deviations are, however, less significant with the post-LHC models. The presence of such deviations seems to be related to a difference between the simulated and the measured zenith angle evolutions of the lateral muon density distributions of EAS, which also causes a discrepancy between the measured absorption lengths of the density of shower muons and the predicted ones at large distances from the EAS core. The studied deficiencies show that all four considered hadronic interaction models fail to describe consistently the zenith angle evolution of the muon content of EAS in the aforesaid energy regime.
The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >1020 eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within ∼50 Mpc through interactions ...with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or γ-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.
The cosmic-ray experiment KASCADE Antoni, T; Apel, W.D; Badea, F ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2003, Letnik:
513, Številka:
3
Journal Article
Recenzirano
KASCADE has been designed to measure air showers of primary cosmic-ray energies in the PeV region and to investigate the
knee phenomenon in the all-particle energy spectrum. Several observations are ...measured simultaneously for each event by different detector systems. The experiment started to take data in 1996 and has been completed and extended since then. The individual detector systems and their performances are described. Also, the experience in long-term operation of the experiment and the interplay between different components is outlined.
Photomultiplier tubes (PMTs) are widely used in astroparticle physics experiments to detect light flashes (e.g. fluorescence or Cherenkov light) from extensive air showers (EASs) initiated by ...statistically rare very high energy cosmic particles when travelling through the atmosphere. Their high amplification factor (gain) allows the detection of very low photon fluxes down to single photons. At the same time this sensitivity causes the gain and signal-to-noise ratio to decrease with collected charge over the lifetime of the PMT (referred to as “ageing”). To avoid fast ageing, many experiments limit the PMT operation to reasonably low night sky background (NSB) conditions. However, in order to collect more event statistics at the highest energies, it is desirable to extend the measurement cycle into (part of) nights with higher NSB levels. In case the signal-to-noise ratio remains large enough in the subsequent reconstruction of the EAS events, lowering the PMT gain in such conditions can be an option to avoid faster ageing. In this paper, performance studies under high NSB with Photonis XP3062 PMTs, as used in the fluorescence detector of the Pierre Auger Observatory, are presented. The results suggest that lowering the PMT gain by a factor of 10 while increasing the NSB level by a similar factor does not significantly affect the PMT performance and ageing behaviour so that detection and offline reconstruction of EASs are still possible. Adjusting the PMT gain according to a changing NSB level throughout a night has been shown to be possible and it follows a predictable behaviour. This allows to extend the measurement cycles of experiments, based on PMTs of type Photonis XP3062 or comparable and exposed to the NSB, to enhance the sensitivity especially at the highest energies where events are very rare.
The KASCADE experiment measures extensive air showers induced by cosmic rays in the energy range around the so-called knee. The data of KASCADE have been used in a composition analysis showing the ...knee at 3–5
PeV to be caused by a steepening in the light-element spectra T. Antoni et al., (KASCADE Coll.), Astropart. Phys. 24 (2005) 1–25. Since the applied unfolding analysis depends crucially on simulations of air showers, different high-energy hadronic interaction models (QGSJet and SIBYLL) were used. The results have shown a strong dependence of the relative abundance of the individual mass groups on the underlying model. In this update of the analysis we apply the unfolding method with a different low energy interaction model (FLUKA instead of GHEISHA) in the simulations. While the resulting individual mass group spectra do not change significantly, the overall description of the measured data improves by using the FLUKA model. In addition data in a larger range of zenith angle are analysed. The new results are completely consistent, i.e. there is no hint to any severe problem in applying the unfolding analysis method to KASCADE data.
We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and ...158 GeV/
c
(
s
=
6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN super proton synchrotron. Two-dimensional spectra are determined in terms of rapidity and transverse momentum. Their properties such as the width of rapidity distributions and the inverse slope parameter of transverse mass spectra are extracted and their collision energy dependences are presented. The results on inelastic p+p interactions are compared with the corresponding data on central Pb+Pb collisions measured by the NA49 experiment at the CERN SPS. The results presented in this paper are part of the NA61/SHINE ion program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. They are required for interpretation of results on nucleus–nucleus and proton–nucleus collisions.
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