Answer to Question #31 Submitted to "Ask the Experts"

Q

A graduate student project at my university will involve sending a microbiology experiment up on the space shuttle. I was asked how the researchers could determine the radiation dose to the organisms used in the experiment. Does NASA, or someone else, have data on this subject or the capability (dosimeter or instrumentation with appropriate calibration) to measure the dose?

A

The procedure is quite routine. We used thermoluminescent dosimeters (TLDs) for dose determination on space shuttles. During my six years at NASA we used LiF (TLD-100) for some low linear energy transfer (LET) measurements on the STS (Space Transport Shuttle) flights. They can be packaged in a sealed container to protect them from the liquid environment where the microorganisms are living. We used nuclear track detectors to measure the LET spectrum of the high Z and high-energy (HZE) particles.

In addition, there is a marvelous National Council on Radiation Protection and Measurements (NCRP) document, though 10 years old, that includes major discussions of dosimetry in space. An abstract of this report (NCRP Report No. 98) can be found on the NCRP's website.

Bill Vermeere, RSO and Vice President
Isotope Products Laboratory, Burbank, CA
bvermeere@isotopeproducts.com