Dosimetry of a Reverberation Chamber for Whole-Body Exposure of Small Animals

In order to determine the whole-body exposure level in small animals inside a reverberation chamber (RC), an ideal electromagnetic (EM) environment has often been assumed inside an RC for numerical dosimetry analyses. In an RC where a strong EM coupling between antennas and animals exists, however, such an EM environment is difficult to be realized, so that it remains unknown whether or not the RC could provide a target dosimetry. In this study, we adopt the Poggio-Miller-Chang-Harrington-Wu-Tsai formulation of the method of moments to directly determine the specific absorption rate (SAR) of a rectangular dielectric phantom placed in an RC, and we demonstrated its validity via comparing the numerical temperature rise with those obtained from experiments. We then demonstrated a nonideal EM environment inside an RC using a prolate spheroid as an exposure target. Furthermore, we performed dosimetry evaluation for multiple rat-shaped tissue-equivalent phantoms inside the RC and determined their whole-body average SARs for many orientations and arrangements of the phantoms. Finally, based on our numerical results, we offered a design rule when using an RC as a whole-body exposure system for small animals.