KASCADE and KASCADE-Grande were multi-detector installations to measure individual air showers of cosmic rays at ultra-high energy. Based on data sets measured by KASCADE and KASCADE-Grande, 90% C.L. ...upper limits to the flux of gamma-rays in the primary cosmic ray flux are determined in an energy range of eV. The analysis is performed by selecting air showers with a low muon content as expected for gamma-ray-induced showers compared to air showers induced by energetic nuclei. The best upper limit of the fraction of gamma-rays to the total cosmic ray flux is obtained at eV with . Translated to an absolute gamma-ray flux this sets constraints on some fundamental astrophysical models, such as the distance of sources for at least one of the IceCube neutrino excess models.
The ‘KASCADE Cosmic ray Data Centre’ is a web portal (
https://kcdc.ikp.kit.edu
), where the data of the astroparticle physics experiment KASCADE-Grande are made available for the interested public. ...The KASCADE experiment was a large-area detector for the measurement of high-energy cosmic rays via the detection of extensive air showers. The multi-detector installations KASCADE and its extension KASCADE-Grande stopped the active data acquisition in 2013 after more than 20 years of data taking. In several updates since our first release in 2013 with KCDC we provide the public measured and reconstructed parameters of more than 433 million air showers. In addition, KCDC provides meta data information and documentation to enable a user outside the community of experts to perform their own data analysis. Simulation data from three different high energy interaction models have been made available as well as a compilation of measured and published spectra from various experiments. In addition, detailed educational examples shall encourage high-school students and early stage researchers to learn about astroparticle physics, cosmic radiation as well as the handling of Big Data and about the sustainable and public provision of scientific data.
In this work, a classical approach was used for calibrating the GESPECOR detector model for computing the full-energy peak efficiency of p-type coaxial HPGe detectors that is based on the use of ...linear least squares optimization. The key element of the work is the multiplicative model developed for approximating the values of the full-energy peak efficiency provided by GESPECOR code. It was linearized using the logarithmic transformation to allow an easy use of the linear least squares optimization. A procedure was also developed to estimate the optimal values of the parameters, describing the p-type coaxial HPGe detectors. Its application to a Canberra detector GC3018 showed that it is possible to determine accurate values of the full-energy peak efficiency computed by GESPECOR code using the optimized parameter values.
LOPES, the LOFAR prototype station, was an antenna array for cosmic-ray air showers operating from 2003 to 2013 within the KASCADE-Grande experiment. Meanwhile, the analysis is finished and the data ...of air-shower events measured by LOPES are available with open access in the KASCADE Cosmic Ray Data Center (KCDC). This article intends to provide a summary of the achievements, results, and lessons learned from LOPES. By digital, interferometric beamforming the detection of air showers became possible in the radio-loud environment of the Karlsruhe Institute of Technology (KIT). As a prototype experiment, LOPES tested several antenna types, array configurations and calibration techniques, and pioneered analysis methods for the reconstruction of the most important shower parameters, i.e., the arrival direction, the energy, and mass-dependent observables such as the position of the shower maximum. In addition to a review and update of previously published results, we also present new results based on end-to-end simulations including all known instrumental properties. For this, we applied the detector response to radio signals simulated with the CoREAS extension of CORSIKA, and analyzed them in the same way as measured data. Thus, we were able to study the detector performance more accurately than before, including some previously inaccessible features such as the impact of noise on the interferometric cross-correlation beam. These results led to several improvements, which are documented in this paper and can provide useful input for the design of future cosmic-ray experiments based on the digital radio-detection technique.
Long term 7Be deposition in Romania Dovlete, C.; Sonoc, S.; Osvath, I. ...
Journal of environmental radioactivity,
December 2021, 2021-12-00, 20211201, Letnik:
240
Journal Article
Recenzirano
This study is based on monthly 7Be deposition data at 29 of the stations of Romania's National Environmental Radioactivity Surveillance Network (NERSN), with different geographical and climatological ...conditions, extending over periods up to 17 years (1979–1995). The 7Be activity in each monthly sample from each station was determined using high-resolution gamma-ray spectrometry performed at the Environmental Radioactivity Laboratory, Bucharest-Afumati.
The annual dynamics of atmospheric deposition of 7Be at each NERSN station showed a strong seasonal trend, very similar to the precipitation regime, with the highest values being observed in spring/summer and the lowest in winter. But the annual 7Be deposition fluxes varied broadly from station to station and year to year, from a minimum of 164 Bq/m2/y (Bechet, 1989) to a maximum of 1388 Bq/m2/y (Baia Mare, 1988). This large space-time variability of deposition was mainly due to the variability of the precipitation regime.
The analysis of experimental data confirms the strong correlation of 7Be deposition data with precipitation, air temperature and the number of sunspots.
Wet and dry deposition data are presented and discussed for four stations where separate dry and wet 7Be deposition measurements were performed.
•Long-term 7Be monthly deposition data from 29 monitoring stations across Romania were analysed in relation with precipitation, temperature and sunspot number.•A strong correlation of 7Be deposition with precipitation and temperature was found.•70% of the average annual deposition of 7Be across the country occurred between April and September.•Mostly the mean ratio of dry/total deposition varied between 13 and 23 %. Near the Black Sea coast this ratio was almost 40 %.
The
137
Cs bulk deposition samples measured in samples collected at Cluj-Napoca in 1965–1985 are analysed and compared with published
137
Cs deposition data from New-York, St. Petersburg, Helsinki ...and Bratislava covering partially/totally the period 1955–1985. A total
137
Cs deposition of 4.2 ± 0.9 kBq/m
2
at Cluj-Napoca is estimated for 1955–1985 based on the comparison of available data. The signature of the atmospheric nuclear tests performed in 1977–1980 is presented using the monthly measured bulk depositions of
106
Ru,
125
Sb,
137
Cs and
144
Ce (1978–1982) and
95
Zr,
103
Ru,
141
Ce for the year 1981, following the last atmospheric nuclear test of October 16, 1980.
The radio technique is a promising method for detection of cosmic-ray air showers of energies around 100PeV and higher with an array of radio antennas. Since the amplitude of the radio signal can be ...measured absolutely and increases with the shower energy, radio measurements can be used to determine the air-shower energy on an absolute scale. We show that calibrated measurements of radio detectors operated in coincidence with host experiments measuring air showers based on other techniques can be used for comparing the energy scales of these host experiments. Using two approaches, first via direct amplitude measurements, and second via comparison of measurements with air shower simulations, we compare the energy scales of the air-shower experiments Tunka-133 and KASCADE-Grande, using their radio extensions, Tunka-Rex and LOPES, respectively. Due to the consistent amplitude calibration for Tunka-Rex and LOPES achieved by using the same reference source, this comparison reaches an accuracy of approximately 10% – limited by some shortcomings of LOPES, which was a prototype experiment for the digital radio technique for air showers. In particular we show that the energy scales of cosmic-ray measurements by the independently calibrated experiments KASCADE-Grande and Tunka-133 are consistent with each other on this level.
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
Odprti dostop
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.
This paper provides guidance for determining the neutron activation profile of core drill samples taken from the biological shield of nuclear reactors using gamma spectrometry measurements. Thus, it ...provides guidance for selecting a model of the right form to fit data and using least squares methods for model fitting. The activity profiles of two core samples taken from the biological shield of a nuclear reactor were determined. The effective activation depth and the total activity of core samples along with their uncertainties were computed by Monte Carlo simulation.
•The paper provides guidance for determining the activity profile of core drill samples.•Effective activation depth and total activity are computed by Monte Carlo simulation.•Exponential fit is the simplest way for evaluating the activity profile of core samples.
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