Status of the SPHERE experiment

Abstract

Status of the SPHERE experiment Related contentResults on the primary CR spectrum and composition reconstructed with the SPHERE-2 detector R A Antonov, S P Beschapov, E A Bonvech et al. Here is presented the current state of the SPHERE-2 balloon-borne experiment. The detector is elevated up to 1 km above the snow surface and registers the reflected VavilovCherenkov radiation from extensive air showers. This method has good sensitivity to the masscomposition of the primary cosmic rays due to its high resolution near the shower axis. The detector consists of a 1500 mm spherical mirror with a 109 PMT cluster in its focus. The electronics record a signal pulse profile in each PMT. In the last 2 years the detector was upgraded: time resolution of pulse registration was enhanced up to 12.5 ns, channel sensitivity was increased by a factor of 3, a new LED-based relative PMT calibration method was introduced, and new hardware and etc. was installed.

Constraints of hadronic interaction models from the cosmic muon observations

“…Figure 1 shows a comparison of the sum of modified GH approximations [13] for primary protons and helium nuclei (dotted line) with the experimental data AMS02 [14] [20], interpreted in terms of the model of QGSJET II-03 shows the oblique crosses (×), and in terms of the model SIBYLL 2.1 -straight crosses (+). The experimental data TUNKA [21] for all primary particles are shown by hollow diamonds ( ), and data SPHERE 2 [22] -dark triangles ( ). The spectra of the primary protons and primary helium nuclei are presented separately in Fig.…”

“…TUNKA [21] (all particles); SPHERE2 2 [22] (all particles); × KASKADE [20] (all particles, QGSJET II-03); + KASKADE [20] (all particles, SIBYLL 2.1).…”