Simulation code for the interaction of 14 MeV neutrons on cells

Area of Science:

• Radiation Biology
• Medical Physics
• Cellular Radiobiology

Background:

• Melanoma cell survival curves irradiated by 14 MeV neutrons exhibit unique characteristics at low dose rates.
• A specific increase in cell killing at 0.05 Gy is followed by a survival plateau between 0.1 and 0.32 Gy.
• Understanding neutron interactions with cellular environments is crucial for radiobiology.

Purpose of the Study:

• To investigate the unusual survival curve of melanoma cells exposed to 14 MeV neutrons at low dose rates.
• To develop and utilize a simulation code for modeling 14 MeV neutron interactions with cellular cultures.
• To correlate energy deposition mechanisms with observed cellular responses.

Main Methods:

• Experimental determination of melanoma cell survival curves under 14 MeV neutron irradiation at varying low dose rates.
• Development of a simulation code to model neutron interactions with cellular and external media.
• Calculation of energy deposition within cell volumes, considering atomic nuclei interactions and charged particle recoils.

Main Results:

• Observed a distinct increase in melanoma cell killing at 0.05 Gy, followed by a plateau in survival.
• Simulation revealed significant energy deposition events due to heavy charged recoils, particularly recoil protons.
• A substantial portion of energy deposition originated from protons emitted from the external medium (flask and culture medium).

Conclusions:

• The unusual features in the melanoma cell survival curve may be partly explained by energy deposition from external recoil protons.
• The simulation code provides insights into the microdosimetry of neutron irradiation in cellular systems.
• Further research is warranted to fully elucidate the role of external energy deposition in neutron radiobiology.