Radiation Dose Enhancement: An Inter-Comparison of Nano-Carbons

We have found that “low-Z” carbon nanotubes can enhance the radiation dose when added to water. We hypothesize that the increased measured dose is due to the physical structure of the nanotubes, credited to the high aspect ratio and curvature, rather than the chemical properties. In this work, we study the radiation dose enhancement for carbon nanotubes, fullerene and laser-induced nano-carbons. The radiation dose was measured using ionization chambers and radiochromic films, in water and solid water phantoms, for multiple x-ray energies. The dose enhancement ratio is defined as the ratio of the measured dose to water (+ nano-carbons) to the measured dose to water (only). This work studies an effect that has not been widely investigated at the time of this publication. Radiation dose enhancement is a useful technique in the field of radiation therapy, especially when dealing with radioresistant cells. Ideally, it increases the dose to the desired site with no additional damage to organs at risk.