Observing of atmospheric hadronic shower on the Barentsburg neutron monitor

Derivation of relativistic SEP properties through neutron monitor data modeling

“…Therefore, the GLE analysis provides less reliable information on the SEP spectrum at rigidities > ~3 GV (~5 GV) during GLE 71 (GLE 60). We first note that the spectrum at 1 GV for GLE 71 is in good agreement with the SEP flux in the direction of anisotropy obtained by [12]. Nevertheless, the SEP intensity in the direction of anisotropy obtained by [9] at 1 GV is about one order of magnitude higher.…”

“…Moreover, for GLE71, the predicted proton spectrum continues to exceed the GCR background (dotted line in Figure 3) even at rigidities > 3 GV (red line). At 3 GV our modeled intensities are almost one order of magnitude higher than those shown in [12] and [9]. Perhaps the anisotropic direction of arrival of solar particles might play a role in the high intensities estimated by our model.…”

“…In our model, the position of the GLE source outside the atmosphere has been considered to be the most significant factor determining the propagation and final registration of the secondaries at ground level. Up to now, this assumption has been considered also in other modeling efforts for different GLEs (see [6], [8], [12]). However, other phenomena, like the diffusion of the secondary particles inside the atmosphere could also have a role in the interpretation of the ground-level intensity time profiles during a GLE and should be taken in detail into account during future analysis.…”

“…In order to determine the direction of arrival of the solar particles at the Earth during a GLE, models can assume either a pitch-angle distribution function (see [12 -13]) or, simply, a latitude and longitude-dependent function (that represents the spatial diffusion of the solar particles around the apparent source direction), without inserting directly the interplanetary magnetic field (IMF) direction information in the model (see [4][5], [7], [10][11], [14]). Whereas the alignment of the solar particle velocity with the IMF could be an indication of propagation along the magnetic field lines almost without scattering ( [12]), [15] argued that there is no reason why the magnetic field measured by a satellite at some point would be the same as the average field sampled by the particles over their orbit. Such was the case of GLE 59 (on 2000 July, 14), when the derived asymptotic latitude of the anisotropy in the Geocentric Solar Ecliptic (GSE) coordinate system deviated from the IMF latitude up to almost 100 0 (opposite hemisphere) during the event maximum [15].…”

EAS hadronic component as registered by a neutron monitor

“…Due to the adaptability of a new high-speed data collection system, it has become possible to bind the master-pulse from the "Carpet", indicating the arrival of an EAS, to the NM pulses. A more detailed description of the data collecting system is given in Balabin et al (2009Balabin et al ( , 2010. It should be pointed out that the "Carpet" detects the EAS electronphoton component, whereas the NM detects hadrons (neutrons, protons and pions) with energy > 50 MeV (Dorman, 1975).…”