The spontaneous assessment of the atmospheric cosmic radiations at aircraft flight altitudes is becoming important to airlines and certification authorities. The largest number of recorded fluxes is usually for neutrons and gamma rays. However, neutrons prove to be the greatest threat to the aircraft’s electronic and electrical systems. In this context, Bombardier has launched a cosmic radiation measurement campaign, where plastic scintillators sensors are used. The use of plastic scintillators is governed by their robustness and their capability to discriminate between neutrons and gamma rays.
The sensor converts deposited energy levels, induced by cosmic radiations recorded into light pulses onboard flying aircraft. The MCNP 6 (Monte Carlo N Particles) software is then used with the appropriate modeling of the plastic scintillator to simulate the corresponding light pulses, which are then compared to the measured test data. All other testing parameters (i.e., altitude, longitude, latitude, and date) are taken in consideration during the simulation process. The scintillator geometrical model and the testing parameters referred to earlier are then used by the built in Function (+F6/DE/DF) in MCNP6 to compute the light energy mean number. Finally, to calculate the light pulses mean number, the following conversion rate of the scintillator was used (8600 photons/1 MeVee.
A mean relative error of 20% is deduced, when comparing the number of measured light pulses with the ones simulated with the MCNP6 software. Relatively, good agreement between both results is achieved, which falls within the acceptable practical tolerance.