Comparison between gold nanoparticle and gold plane electron emissions: a way to identify secondary electron emission.

To understand the nanoparticle radiosensitising effect observed in the radiotherapy context, it is necessary to study the nanoparticle electron emission under x-ray irradiation, which is one of the causes of the radiosensitisation. In this paper, we compare the electron energy spectrum of gold samples irradiated by 1253.6 eV x-ray photons for energies down to 2 eV for nanoparticles and for a plane surface. This comparison highlights important differences due to nanoparticle properties especially at low energy, allowing the identification of strong nanoparticle secondary electron emission. This strong nanoparticle emission could play a very important role in radiosensitisation mechanisms.