Physics Bucharest 2017

Ionometric standard



water P

Dose in a point P in water:

w

= 

 (S/  ) c,w

D w

w

measurement in water with air-filled i.c.

air

= 

 (S/  ) c,air

D air

P

air

water

Bragg-Gray cavity theory:  air

= 

w

valid if: - dimensions of air are small enough to not disturb charged particle fluence  w - charged particles are only generated in w

 (S/  ) c,w

/ (S/  ) c,air

D w

= D air

 s w,air

D w

= D air