| The discovery of radiation resulted in significant benefits; however, potential negative
effects were also introduced. Human exposure needed to be measured and correlated to health
risk. Materials were developed which would approximate human tissue to be able to accurately
measure absorbed dose.
A major challenge with the measurement of personal exposure is backscatter, or the
reflection of radiation from the person back onto the radiation measuring device, resulting in
measurements that are not representative of the incident radiation field.
ANSI/HPS N13.11 standardized the measurement of external radiation exposure,
prescribing a polymethyl methacrylate (PMMA) slab phantom for dosimetry qualifications.
Other materials have been developed to simulate tissue. This project compares the
photon backscatter caused by the PMMA phantom to the Radiological Environmental Sciences
Laboratory (RESL) Tissue-Equivalent and Lawrence Livermore National Laboratory (LLNL)
Realistic Torso Phantoms.
This study resulted in statistically measurable differences in the backscatter of the three
phantoms.
Keywords: Backscatter, Phantom, Tissue Equivalent |