|Message: Bragg curve profiles of protons in water||Not Logged In (login)|
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I simulated a water cuboid (50 m X 25 m X 25 cm) of several layers irradiated with a pencil beam of mono energetic protons and tracked only the primary particle to estimate its depth dose profile. The aim was to calculate Range Vs Primary particle energy (100 MeV to 10 GeV).
What I found is that for lower energies e.g. 100 MeV to around 800 MeV, the Bragg peak is clearly visible but for higher energies it becomes lesser and lesser prominent. And also with increasing energies the largest dose deposition occurs at outer layers and reduces continuously with depth. I have difficulty in understanding this difference in depth dose distribution characteristics.
I think there is some physical phenomenon that occurs for higher energies. I would have imagined that besides the increasing range of protons with increasing primary energies in water and also the amount of energy or the dose deposited, the depth dose distributions (=>Bragg curves) should look similar in shape for all energies. Because the energy loss for all charged ions with depth should increase as the particles slows and should reach a maximum before stopping down completely.
Any guidance on this matter will be very helpful. Thanking you.
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