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.
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.
TRD detector development for the CBM experiment Petriş, M.; Petrovici, M.; Cătănescu, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
732
Journal Article
Recenzirano
A transition radiation detector (TRD) prototype based on a single multiwire proportional chamber coupled with a small drift region was developed for the innermost part of the CBM-TRD subsystem. It ...preserves the same gas thickness for transition radiation absorption as the double-sided TRD prototype for which a pion misidentification probability of better than 1% for a six layer configuration was obtained. In the same time it fulfills the requirement of a high geometrical efficiency of CBM-TRD stations. The readout electrode geometry with triangular shaped pads gives access to a two-dimensional position information with a single TRD layer. The detector was tested with a mixed electron/pion beam of 1–5GeV/c momentum at the CERN PS accelerator. A pion misidentification probability of 1.18% for a six layer configuration based on this architecture was obtained. The two-dimensional position resolutions (along and across the pads) were measured. The pad signals were processed using a new front-end electronics called Fast Analog Signal Processor (FASP), designed for high-counting-rate environments. CADENCE simulations were used for further optimization of the FASP amplifier for operating this new architecture.
Two-dimensional position sensitive transition radiation detector Petriş, M.; Petrovici, M.; Cătănescu, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2013, Letnik:
714
Journal Article
Recenzirano
A new transition radiation detector (TRD) prototype foreseen to fulfill the requirements of the TRD subdetector of the CBM experiment at FAIR has been designed, constructed and tested with electrons ...and pions of a few GeV/c. The detector prototype was build with the original TRD architecture which preserves the high conversion efficiency of transition radiation in a single TRD layer. This TRD architecture is based on two multiwire proportional chambers readout by a common double-sided pad read-out electrode. The triangular shape of the readout pads gives access to the position information in both coordinates which defines the readout electrode plane. Pion efficiency as a function of number of TRD layers and position resolution were studied using electron and pion beams delivered by PS at CERN. Dedicated front-end electronics, designed for high counting rate environment was used. An extrapolated pion efficiency of 0.5% for a six layer TRD configuration at 90% electron efficiency using a regular foil radiator was obtained. The position resolution across the pads is of the order of 320μm and along the pads of 5.5mm.
► Two-dimensional position sensitive TRD. ► Highly efficient dedicated front-end electronics. ► Very good pion rejection of ∼200 for six TRD layers.
We present the results of an analysis of the large-scale anisotropy of cosmic rays in the PeV range. The Rayleigh formalism is applied to the right ascension distribution of extensive air showers ...measured by the KASCADE (Karlsruhe Shower Core and Array Detector) experiment. The data set contains about 10 super(8) extensive air showers in the energy range 0.7-6 PeV. No hints of anisotropy are visible in the right ascension distributions in this energy range. This accounts for all showers, as well as for subsets containing showers induced by predominantly light or heavy primary particles, respectively. Upper flux limits for Rayleigh amplitudes are determined to be between 10 super(-3) at a primary energy of 0.7 PeV and 10 super(-2) at 6 PeV.
Lateral distributions for electrons and muons in extensive air showers measured with the array of the KASCADE experiment are compared to results of simulations based on the high-energy hadronic ...interaction models QGSJet and SIBYLL. It is shown, that the muon distributions are well described by both models. Deviations are found for the electromagnetic component, where both models predict a steeper lateral shape than observed in the data. For both models the observed lateral shapes of the electron component indicate a transition from a light to a more heavy composition of the cosmic ray spectrum above the knee.
.
Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high ...temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (
s
N
N
=
2.7--4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (
μ
B
>
500
MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter.
A survey of the northern hemisphere for astrophysical point sources with continuous emission of high-energy cosmic rays is presented. Around 4.7 x 10 super(7) extensive air showers with primary ...energies above ~300 TeV measured by the KASCADE detector field are selected for this analysis. Besides the sky survey, a search for signal excess in the regions of the Galactic plane and of selected point-source candidates has been performed. There is no evidence for any significant excess. This is valid for an analysis of all recorded showers, as well as for a data set enhanced by gamma-ray-induced showers. An upper flux limit of around 3 x 10 super(-10) m super(-2) s super(-1) for a steady point source that transits the zenith is obtained. Additionally, the distribution of the arrival directions of extensive air showers with energies above 80 PeV was studied by an autocorrelation analysis.
The flux of cosmic-ray-induced single hadrons near sea level has been measured with the large hadron calorimeter of the KASCADE experiment. The measurement corroborates former results obtained with ...detectors of smaller size if the enlarged veto of the 304 m super(2) calorimeter surface is accounted for. The program CORSIKA/QGSJET is used to compute the cosmic-ray flux above the atmosphere. Between E sub(0) = 300 GeV and 1 PeV the primary proton spectrum can be described with a power law parameterized as dJ/dE sub(0) = (0.15 plus or minus 0.03)Eimage m super(-2) s super(-1) sr super(-1) TeV super(-1). At the lower energy end the proton flux compares well with the results from recent direct measurements.
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