Prof. Harm Moraal (North-West University, South Africa)
Seventy-one ground-level enhancements (GLEs) in the counting rates of cosmic-ray detectors, due to outbursts of solar energetic particles, have been observed since 1942. It is well-known that these events are associated with solar flares and coronal mass ejections (CMEs), and that they originate primarily from western longitudes on the surface of the sun. In addition, studies of the time...
428. Observations and Monte Carlo Simulation of the Princess Sirindhorn Neutron Monitor at a Vertical Rigidity Cutoff of 16.8 GV
Dr Pierre-Simon MANGEARD (National Astronomical Research Institute of Thailand, Mahidol University)
Neutron monitors (NMs) are large ground-based instruments for precise time tracking of the variations in the Galactic cosmic ray (GCR) flux at the GeV-range. NMs count the secondary particles (mostly neutrons) issued from the interaction of the cosmic rays in the Earth's atmosphere. The sensitivity to GCR variations depends on the geomagnetic cutoff at the location of measurement as well as on...
Helena Kruger (North-West University, Potchefstroom)
Two small neutron monitors were built in 2002 to intercalibrate the approximately 40 stationary neutron monitors around the world, in order to study the modulation of cosmic rays derived from the resulting differential response functions. Due to electronic development during the past decade, the electronics heads were redesigned in 2011 and due to cheaper and more efficient counter tubes, the...
21. A New neutron monitor yield function computed for different altitudes: Application for a GLE analysis
Alexander Mishev (INRNE-BAS)
At present the world wide neutron monitor (NM) network provides continuous information about cosmic ray (CR) variations in the vicinity of Earth. In addition, analyses of ground level enhancements (GLEs) are also based on the NM data records. It is important to have precise information for the NM yield function for primary CRs, which is crucial for an analysis of GLEs. Here we present a newly...
1038. Variations of the vertical cutoff rigidities for the world wide neutron monitor network over the period of continues monitoring of cosmic rays
Prof. Lev Dorman (IZMIRAN (Russia) and Tel Aviv University (Israel))
Gvozdevsky1 B., Dorman2,3 L., Abunin2 A., Preobrazhensky2 M., Gushchina2 R., Belov2 A., Eroshenko2 E., Dai3 U., Pustil’nik3 L., Yanke2 V. 1- Polar Geophysical Institute, 184209, Firsmana str., 14, Apatity, Russia 2- IZMIRAN, Kalushskoe ave., 4, Troitsk, Moscow, 142190, Russia 3. Israel Cosmic Ray and Space Weather Center with Emilio Segre’ Observatory on Mt. Hermon, affiliated to Tel Aviv...
Paul Evenson (University of Delaware)
Secular variation of the Earth's geomagnetic fields is well known to change the cutoff rigidity, and thereby the count rate of low latitude neutron monitors. Such changes are generally assumed to be irrelevant to so called atmosphere limited neutron monitors at high latitudes. We have documented a secular change in the count rate of the neutron monitor at Amundsen – Scott Station, located at...
Dr Natalia Barbashina (National Research Nuclear University MEPhI (Moscow Engineering Physics Institute))
Investigations of Forbush decreases in a muon flux have certain peculiarities. First, muons are sensitive to the higher energies (relative to neutrons) of primary cosmic rays (PCRs), opening up new possibilities for studying the heliospheric perturbations responsible for the modulation of high energy PCRs. Second, muons save the direction of the primary particle motion, allowing to obtain the...
Dr Xi Luo (North-West University, Potchefstroom, South Africa)
We have constructed a 3-D numerical model for studying Forbush Decreases (FDs) in the heliosphere. It incorporates 3-D propagation barriers, with enhanced cooling inside, into a time-dependent Parker type modulation model using a Stochastic Differential Equation (SDE) approach. This numerical model simultaneously takes into account the effect of solar wind convection, regular drift plus...