Scientists at the Institute of Nuclear Physics of the Polish Academy of Sciences in the southern city of Kraków analyzed data collected during the uncrewed mission, which took NASA's Orion spacecraft around the Moon in November and December 2022.
More than 10,000 small radiation detectors were placed inside two human-shaped models aboard Orion to measure how cosmic radiation would affect astronauts.
These included several dozen experimental lithium fluoride detectors developed in Kraków and around 600 other detectors supplied by the Polish institute.
The findings, published in the journal Radiation Measurements, show that radiation doses near the Moon are higher than those experienced by astronauts orbiting Earth, although the difference is smaller than expected.
Prof. Paweł Bilski, a co-author of the study, explained that astronauts in low Earth orbit are exposed to relatively low-energy protons trapped by Earth's magnetic field in the Van Allen radiation belts.
These belts are absent near the Moon, where astronauts face greater exposure to highly energetic galactic cosmic radiation capable of penetrating the entire human body.
Measurements inside the models showed that radiation was distributed almost uniformly.
"Our measurements show that, because of the large amounts of galactic radiation, total doses near the Moon are indeed higher than in Earth orbit, but not nearly as much as one might intuitively expect," Bilski said.
The Polish researchers also tested a new method of measuring radiation using lithium fluoride crystals. The detectors work much like photographic film, recording the paths of individual particles.
When illuminated with blue light in a laboratory, the affected crystals emit red fluorescent light, allowing scientists to examine the tracks under a microscope.
Unlike conventional plastic detectors, which require chemical treatment before examination, the Polish devices can be analyzed directly.
Results differed by no more than 15 percent from measurements obtained using conventional detectors across the energy range covered by both technologies.
"We also recorded many particle tracks that deposited less energy than the lower detection threshold of existing detectors," Bilski said.
The detectors, developed in Kraków over the past decade, are smaller than conventional devices, provide greater detail and can register a wider range of particles and energies.
The research formed part of the international Matroshka AstroRad Radiation Experiment (MARE), which aims to improve understanding of radiation risks during future human missions beyond Earth's protective magnetic field.
The Polish contribution was funded through a grant from the National Science Centre.
(rt/gs)
Source: PAP, tvp.info