Investigation of the Influence of the Position Inside a Small Aircraft on the Cosmic-Radiation-Induced Dose

Abstract

This article report the measurements on-board a small aircraft at the same altitude and around the same geographic coordinates. The measurements of Ambient Dose Equivalent Rate (H*(10)) were performed in several positions inside the aircraft, close and far from the pilot location and the discrimination between neutron and non-neutron components. The results show that the neutrons are attenuated close to fuel depots and the non-neutron component appears to have the opposite behavior inside the aircraft. These experimental results are also confronted with results from Monte Carlo simulation, obtained with the MCNPX code, using a simplified model of the Learjet-type aircraft and a modeling of the standard atmosphere, which reproduces the real energy and angular distribution of the particles. The Monte Carlo simulation agreed with the experimental measurements and shows that the total H*(10) presents small variation (around 1%) between the positions inside aircraft, although the neutron spectra present significant variations.

Simulation of Cosmic Radiation Transport Inside Aircraft for Safety Applications

“…The aircraft model was made in a simple way and consists of 58 cells and 12 different materials to describe its structure, material, and occupants. The geometry of the aircraft is detailed in a previous work [17] which demonstrates the validity of the simulations by comparing the ambient dose equivalent rate given by the aircraft Monte Carlo simulation results with experimental data taken in flight. From the results of this previous work, we found that the experimental and simulated results are in good agreement within 3%, evidencing that, although the aircraft model was built simply, the set represented by the aircraft model and the methodology of the atmosphere radiation source is a good way to represent reality.…”

“…Each source built on MCNPX has a different FNF factor and depends on the number of neutrons obtained by gPartAt, which was originated from the primary protons and alphas from cosmic radiation incidents at the top of the atmosphere. The explanations of this equation and the FNF factor are given in previous work [17]. Fig.…”

“…This simulation was made with a neutron source distributed uniformly over two flat surfaces delimited by a cylinder wall with reflective properties, which simulates one 3D infinite atmospheric radiation environment using a finite geometry model, with the aircraft placed inside this volume. More details about the flight radiation environment and this methodology can be found in previous work [17]. The primary spectra and angular distributions at flight altitudes were obtained by the Geant4 based gPartAt platform [20] [21] using QGSP_BERT-HP physics list of Geant4.…”

Vulnerability of Economic Sectors to Geomagnetic Storms and Mitigation Strategies

“…In SEU, by using an error correcting code it is easier to fix a software issue however when MBU is considered, it is not as straight forward as SEU. For full recovery, the system needs to be restarted (Prado, 2013) (Maniatakos, 2012) (Australian Transport Safety Bureau, 2008) that is reported. In the report, SEE is given as the most probable reason for such a damage.…”