We present radio observations of the Moon between \(35\) and \(80\) MHz to demonstrate a novel technique of interferometrically measuring large-scale diffuse emission extending far beyond the primary ...beam (global signal) for the first time. In particular, we show that (i) the Moon appears as a negative-flux source at frequencies \(35<\nu<80\) MHz since it is `colder' than the diffuse Galactic background it occults, (ii) using the (negative) flux of the lunar disc, we can reconstruct the spectrum of the diffuse Galactic emission with the lunar thermal emission as a reference, and (iii) that reflected RFI (radio-frequency interference) is concentrated at the center of the lunar disc due to specular nature of reflection, and can be independently measured. Our RFI measurements show that (i) Moon-based Cosmic Dawn experiments must design for an Earth-isolation of better than \(80\) dB to achieve an RFI temperature \(<1\) mK, (ii) Moon-reflected RFI contributes to a dipole temperature less than \(20\) mK for Earth-based Cosmic Dawn experiments, (iii) man-made satellite-reflected RFI temperature exceeds \(20\) mK if the aggregate cross section of visible satellites exceeds \(80\) m\(^2\) at \(800\) km height, or \(5\) m\(^2\) at \(400\) km height. Currently, our diffuse background spectrum is limited by sidelobe confusion on short baselines (10-15% level). Further refinement of our technique may yield constraints on the redshifted global \(21\)-cm signal from Cosmic Dawn (\(40>z>12\)) and the Epoch of Reionization (\(12>z>5\)).
KASCADE-Grande is the extension of the multi-detector setup KASCADE to cover a primary cosmic ray energy range from 100 TeV to 1 EeV. The enlarged EAS experiment provides comprehensive observations ...of cosmic rays in the energy region around the knee. Grande is an array of 700 × 700 m
2 equipped with 37 plastic scintillator stations sensitive to measure energy deposits and arrival times of air shower particles. LOPES is a small radio antenna array to operate in conjunction with KASCADE-Grande in order to calibrate the radio emission from cosmic ray air showers. Status and capabilities of the KASCADE-Grande experiment and the LOPES project are presented.
The main golas of the KASCADE (KArlsruhe Shower Core and Array DEtector) experiment are the determination of the energy spectrum and elemental composition of the charged cosmic rays in the energy ...range around the knee at ≈ 5 PeV. Due to the large number of measured observables per single shower a variety of different approaches are applied to the data, preferably on an event-by-event basis. First results are presented and the influence of the high-energy interaction models underlying the analyses is discussed.
Using a large set of simulated extensive air showers, we investigate universality features of electron and positron distributions in very-high-energy cosmic-ray air showers. Most particle ...distributions depend only on the depth of the shower maximum and the number of particles in the cascade at this depth. We provide multi-dimensional parameterizations for the electron-positron distributions in terms of particle energy, vertical and horizontal momentum angle, lateral distance, and time distribution of the shower front. These parameterizations can be used to obtain realistic electron-positron distributions in extensive air showers for data analysis and simulations of Cherenkov radiation, fluorescence signal, and radio emission.
New data on the muon/electron ratio derived from the KASCADE extensive air shower experiment are presented. This ratio is known to be the most sensitive parameter in the determination of the mass of ...the primary particle when using ground array data. The particle numbers are measured with the KASCADE array comprising 500
m
2 of ε/γ- and 620
m
2 of
μ- detectors. The primary mass is inferred on an event-by-event basis by comparing the experimental data to corresponding EAS simulations. We observe a change towards a heavier composition with increasing energy above the knee. The sensitivity of this result to the specific hadronic interaction model employed in the simulations (e.g. VENUS and QGSJET) is discussed.
A measurement of the absolute fluorescence yield of the 337 nm nitrogen band, relevant to ultra-high energy cosmic ray (UHECR) detectors, is reported. Two independent calibrations of the fluorescence ...emission induced by a 120 GeV proton beam were employed: Cherenkov light from the beam particle and calibrated light from a nitrogen laser. The fluorescence yield in air at a pressure of 1013 hPa and temperature of 293 K was found to be \(Y_{337} = 5.61\pm 0.06_{stat} \pm 0.21_{syst}\) photons/MeV. When compared to the fluorescence yield currently used by UHECR experiments, this measurement improves the uncertainty by a factor of three, and has a significant impact on the determination of the energy scale of the cosmic ray spectrum.
The KASCADE-Grande experiment operates at Karlsruhe Institute of Technology (KIT) in Germany. Itʼs aim is the study of the primary cosmic radiation, through Extensive Air Shower detection, in the ...range 10
16–10
18 eV. Here, measurements are of main interest to understand the high energy evolution of cosmic radiation: a change in the slope of the heavy primary spectrum is expected (as measured at lower energies for lighter primaries) as a possible confirmation of the predicted astrophysical mechanisms; moreover, in this range the transition from galactic to extragalactic radiation is supposed to take place and the observations could clarify the features of this transition, putting the basis for the interpretation of the data at the highest energies. For these tasks KASCADE-Grande fulfills very well the requirements, both concerning the acceptance and the experimental performances. The experiment is constituted by two co-operating arrays of detectors: the KASCADE array, with its 252 detectors in a dense grid of 200×200 m
2 and the Grande array, made of 37 detectors arranged on a wider area of 700×700 m
2. The Grande array samples the total charged particles size of the air shower, while the KASCADE array provides the muon size In this contribution, KASCADE-Grande measurement of the cosmic ray primary energy spectrum is presented. The exploited technique, calibrated with simulations, combines the charged particles component and muon component on a shower by shower basis, performing the energy estimation of each primary event. Other techniques are also performed, for a better evaluation of systematics and a check of consistency of the hadronic interaction model used in simulations.
The interpretation of extensive air shower measurements often requires the comparison with EAS simulations. These calculations rely on hadronic interaction models which have to extrapolate into ...kinematical and energy regions not covered by present-day collider experiments. The KASCADE experiment with its large hadron calorimeter and its detectors for the electromagnetic and muonic components provides experimental data to check hadronic interaction models. For the EAS simulations the program CORSIKA with several hadronic event generators embedded is used. Different hadronic observables are investigated as well as their correlations with the electromagnetic and muonic components. Comparing the interaction models QGSJET 98, NEXUS II, and DPMJET 11.5, it is found, that QGSJET describes the data best.
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