OSU's Optically Stimulated Luminescence (OSL) Technique Takes Flight

Thursday, August 11, 2005

Researchers at Oklahoma State University (OSU) have been working for the past few years to develop a technique called Optically Stimulated Luminescence (OSL) as a method to measure radiation exposure to astronauts during space flight. NASA funded the research led by Dr. Stephen W. S. McKeever, vice president for research and technology transfer, along with Dr. Eduardo Yukihara, assistant professor of physics, and Dr. Ramona Gaza, former graduate student now working for NASA’s Johnson Space Center.

The result of these efforts is that the OSL technique developed by OSU was used by NASA in badges (know as a “dosimeter”) worn by astronauts aboard the latest Discovery mission, STS-114. Research results presented by the OSU team at international meetings and in discussions with NASA convinced the NASA Space Radiation Analysis Group (SRAG) to use OSU’s OSL technique as part of the radiation measurement “badges” worn by astronauts on the Discovery mission. Gaza is currently setting up OSL facilities for SRAG at NASA’s Johnson Space Center.

The OSL technique uses luminescence emitted from a radiation-sensitive material to measure the radiation exposure. The material used by the OSU group was aluminum oxide and NASA needed to make modifications to current astronaut dosimeter badges to accommodate the aluminum oxide materials. The radiation-sensitive aluminum oxide is made in Stillwater, Oklahoma at the Crystal Growth Division of Landauer, a Chicago-based company, who mass produces aluminum oxide crystals for about 1.5 million customers.

NASA accepted the first prototype modifications made to the badges by OSU’s Physics Department using OSU’s design. Mike Lucas, OSU Physics Department, made additional component parts for NASA to include in the radiation dosimeter badges as part of the OSL system. Parts shipped to NASA for the new badges were assembled by NASA for use by astronauts on Shuttle mission STS-114. NASA will use OSL and aluminum oxide as part of their astronaut dosimeter badge in future flights.

In addition, as part of a large multi-national consortium to estimate radiation doses inside the human body while in space, the OSU team is taking part in an experiment called MATROSHKA, which is currently flying on the International Space Station. Later this year, samples from MATROSHKA will return to earth on the Soyuz spacecraft for analysis.

For more information about OSU’s research programs, contact the Office of the Vice President for Research and Technology Transfer at 405-744-6501 or visit our website at www.vpr.okstate.edu