Recent progress in space weather research for cosmic radiation dosimetry

Abstract

The radiation environment in space is a complex mixture of particles of solar and galactic origin with a broad range of energies. In astronaut dose estimation, three sources must be considered: galactic cosmic radiation, trapped particles, and solar energetic particles (SEPs). The astronaut dose due to SEP exposure during a space mission is more difficult to estimate than the other components because the occurrence of a large solar particle event cannot be predicted by the current space weather research. Thus, several models have been proposed to estimate the worst-case scenario and/or the probability of the integral SEP fluence during a particular space mission, considering the confidence level, solar activity, and duration of the mission. In addition, recent investigations of the cosmogenic nuclide concentrations in tree rings and ice cores have revealed that the sun can cause solar particle events much larger than the largest event recorded in the modern solar observations. If such an extreme event occurs during a mission to deep space, astronauts may suffer from radiation doses in excess of the threshold value for some tissue reactions (0.5 Gy) and their career limit (0.6–1.2 Sv). This article reviews the recent progress made in space weather research that is useful for cosmic radiation dosimetry.

Fabrication of a Gd2O3-Based Film to Shield from Space Radiation inside Aircraft and Its Effectiveness

“…At aircraft flight altitudes, the proportion of the neutron dose from the ground is high (approximately 50%), and neutrons with an energy of approximately 1 MeV, which have the highest biological effect on the human body, are distributed in large quantities, as shown in Figure 11 [28,29]. As shown in Figure 12, gadolinium has a high neutron reaction cross-section; therefore, it is effective in shielding low-energy neutrons.…”

An Optimized Solution to Long‐Distance Flight Routes Under Extreme Cosmic Radiation

“…Thus the detection and alert of SPE are important. This work can be accomplished in two approaches: high‐energy proton detectors on Geostationary Operational Environmental Satellites (GOES) or neutron monitors on the ground (Sato, 2020). Several systems have been developed to issue the SEP exposure alert at flight altitudes, such as Warning System for AVIation Exposure to Solar energetic particle (WASAVIES) (Sato et al., 2014), AVIation DOSimetry (AVIDOS) (Latocha et al., 2009), Nowcast of Aerospace Ionizing Radiation System (NAIRAS) (Mertens et al., 2013), National Tsing Hua University (NTHU) Flight Dose Calculator (Yang et al., 2019), and Civil Aviation Research Institute (CARI)‐7A (Copeland, 2021), benefiting the commercial airline industry and other authorities to mitigate the exposure to a high level of cosmic radiation.…”