December 22, 2012
Neutron Radiation Detectors Placed Throughout International Space Station
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redOrbit Staff & Wire Reports - Your Universe Online
The radiation measured by the devices is called neutron radiation. It is one of the more dangerous types officials from the Canadian Space Agency (CSA) explained recently in a statement, and is caused by high-energy neutron particles that are created when charged particles collide with physical matter.
"Neutron radiation is considered to be one of the most severe of all types of radiation experienced in space as it can cause biological damage," the CSA said. "It represents approximately 30 percent of the total exposure for those aboard the station“¦ [and] these high-energy particles can shoot through delicate body tissues, and through long-term exposure, they can damage DNA and potentially cause cataracts, bone marrow damage or even cancer."
The instruments Hadfield and fellow crew member Roman Romanenko carried are called bubble detectors, and they are part of Radi-N2, a second-generation neutron radiation monitoring program. The two astronauts, as well as colleague Tom Marshburn and the gear, arrived safely at the station Friday following two days in orbit.
"Radi-N2 is Canada's second generation of neutron radiation monitoring aboard the station and continues on where fellow Canadian astronaut Robert Thirsk and the original Radi-N experiment left off in 2009," the agency said, adding the program was "a collaborative effort between the CSA and Russia's RSC-Energia and State Research Center of Russia Institute of Biomedical Problems, or IBMP, Russian Academy of Sciences."
The bubble detectors have been specially designed to ignore other types of radiation while focusing solely on neutrons. Hadfield and Romanenko will be placing eight of the instruments, each of which are approximately the size of a finger, at various locations throughout the space station.
"Each detector is filled with a clear polymer gel, inside which are liquid droplets. When a neutron strikes the test tube, a droplet may be vaporized. This creates a visible gas bubble in the polymer. Each bubble, which represents neutron radiation, is then placed within an automatic reader and counted," the CSA said.
They added the devices "have been used in space for more than two decades," are trusted "because of their accuracy and convenience," and "will provide critical information for potential future human missions to the moon, asteroids and eventually Mars."
Image 2 (below): Radi-N2 bubble detectors are filled with a gel, inside which are liquid droplets that help quantify neutron radiation inside the International Space Station. (Canadian Space Agency)