Energy deposition around swift carbon ion tracks in liquid water.
Dapor M., Taioli S., Abril I., de Vera P., Garcia-Molina R.
V - Biofisica e fisica medica
GSSI Ex ISEF - Aula B - Venerdì 27 h 15:30 - 19:00
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The use of energetic ion beams for cancer treatment is based on the sharp and well-located dose maximum (the so-called Bragg peak) appearing at the end of their depth-dose curve. The advantages of ion beams as compared to other radiations lie mainly on the precision with which the tumor can be irradiated, with minor side effects to the surrounding healthy regions. A precise knowledge of the energy loss by swift ions in targets of biological interest (liquid water and cell components) is mandatory (i) to suitably model the depth-dose profiles and (ii) to know the spatial distribution of the energy deposited around the ion's track by the secondary electrons generated by the projectile and subsequent electron cascade, which can propagate appreciable amounts of energy relatively far away from the ion's path. Given the importance of low energy electrons in producing bio-damage, it is essential to know in detail the spatial and energy distribution of electrons around the tracks of ions for representative energies around the Bragg peak region. The whole cascade of secondary electrons has to be followed, because any truncation or cut off would underestimate the secondary electron emission yield. In this communication the radial distribution of the energy deposited around swift carbon ion paths in water by the transport of secondary electrons, obtained by a detailed Monte Carlo simulation, is presented.