Neutron spectra measurements in the south Atlantic anomaly region

Monte Carlo transport simulation for a Long Counter neutron detector employed as a cosmic rays induced neutron monitor at ground level

“…In Table 3, a summary of the simulations results and the LC efficiency calculated from experimental measurements [8] is presented. Table 3 we see that the agreement between the simulation results is exellent, indicating that both sources of neutrons are consistent with each other.…”

“…Pazianotto In the second approach, the Long Counter efficiency was computed in the same manner. The neutron sources were modelled using the MCNPX code for the cosmic-ray induced neutron spectrum measured at Itatiaia Mountain (2400 km altitude), in Brazil [8] shown in Figure 2. One can see three peaks in the spectrum, associated with its thermal, evaporation and spallation components.…”

The prototype of a detector for monitoring the cosmic radiation neutron flux on ground

“…High energy neutrons are produced by interactions between primary cosmic rays and atmospheric atoms and undergo moderation, resulting in a wide energy spectrum, ranging from thermal energies to several hundreds of MeV [2,3], that is known as the cosmic-ray-induced neutron spectrum (CRINS).…”

Verification of Response of Neutron Monitor for In-Flight Neutron Dosimetry

“…The equipment was exposed to different distances from the standard sources, ranging from about 0.86 m up to 4.7 m, where the ambient dose equivalent of the neutron field is known with a combined average uncertainty varying from around 9 to 2% for sources of 252 Cf and 241 Am/Be respectively. Such uncertainty is a combination average of the sources of uncertainty given in Table 2. In the calibration process, we used a shadow cone constructed in accordance with the Safety Report Series 16 (IAEA, 2000), and for each measurement point (distance from source) calibration was performed in two stages, with and without using the shadow cone, so as to eliminate the contribution of the components originating from neutrons scattered in the environment, according to the methodology used in Federico et al, (2010a).…”

“…In recent decades, the problem of controlling the level of ionizing radiation dose received by aircrew and sensitive equipment has received great attention and motivated several studies in specialized international literature (FAA, 1990;Wilson et al, 1998;Bartlett, 2004;Edwards et al, 2004;Hajek et al, 2004). In Brazil, these studies were initiated by the Brazilian Air Force (FAB) in conjunction with research institutions from the National Commission on Nuclear Energy (CNEN) (Federico et al, 2010a(Federico et al, , 2010b(Federico et al, , 2012.…”