The discussion centers on the Bragg-Gray Theory in radiophysics, specifically its application in calculating dose in water using a Bragg-Gray cavity at 45 MV. Participants clarify that the theory assumes charged particle equilibrium at the cavity's position, with ionization proportional to absorbed dose. The user initially expected differing results from the Bragg-Gray cavity and electronic equilibrium calculations but found similar values, leading to insights about the less restrictive nature of charged particle equilibrium at lower energies.
PREREQUISITESRadiophysicists, medical physicists, and researchers involved in radiation therapy and dose calculations will benefit from this discussion.
Yes, sorry, Bragg- Gray. I mean (as exercise) I calculate the dose in water for 45 MV by Bragg-Gray cavity and by the equation for electronic equilibrium (i do not know its proper name) and I obtained similar values. My question is: Why? I thought that i must obtain very diferent values.gleem said:Your mean Bragg-Gray don't you? Could you please elaborate on your issue? Your question does not make sense as stated,
Well I found the answer. It seems that the charged particle equilibrium it is not a restrictive condition; particulary at low energies is less restrictive than at high energies.gleem said:Bragg Gray Theory assumes that charged particle equilibrium exists at the position of a small cavity in a medium , that the ionization produced in the cavity is proportional to the absorbed dose and that the cavity does not significantly change the spectral characteristics of the ionizing radiation at the cavity position.