In radiological physics, charged-particle equilibrium (CPE) occurs when the number of
charged particle
In physics, a charged particle is a particle with an electric charge. For example, some elementary particles, like the electron or quarks are charged. Some composite particles like protons are charged particles. An ion, such as a molecule or atom ...
s leaving a volume is equal to the number entering, for each energy and type of particle.
When CPE exists in an irradiated medium, the
absorbed dose
Absorbed dose is a dose quantity which represents the specific energy (energy per unit mass) deposited by ionizing radiation in living matter. Absorbed dose is used in the calculation of dose uptake in living tissue in both radiation protecti ...
in the volume is equal to the collision
kerma
Kerma was the capital city of the Kerma culture, which was founded in present-day Sudan before 3500 BC. Kerma is one of the largest archaeological sites in ancient Nubia. It has produced decades of extensive excavations and research, including t ...
.
In order for this to occur, energy is needed.
References
Nuclear physics
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