Experimental and numerical determination of SAR distributions within culture flasks in a dielectric loaded radial transmission line

The effect of dielectric loading on the cell layer specific absorption rate (SAR) within a T-75 culture flask being irradiated within a transverse ele ctromagnetic (TEM) cell was studied both experimentally and numerically. Di rect thermal measurements of a T-75 containing 40 mL of culture medium and resting upon a 3-mm-thick slab of alumina ceramic (epsilon(r) = 9.6) reveal ed that. compared to the same flask resting upon a foam slab (epsilon(r) = 1.0) of the same thickness, the average SAR at the cell layer was increased roughly fourfold. This fourfold increase is significant experimentally bec ause it allows biologists to perform experiments over a larger range of SAR values needed to determine possible dose-response curves without the costs and difficulties of a fourfold increase in amplifier power. Finite-differe nce time-domain (FDTD) simulations of the SAR distribution were in good qua ntitative agreement with the experimental measurements. It is concluded tha t FDTD modeling can be a cost effective and scientifically acceptable means of obviating the thermal measurement of SAR.