Dose 2016

5.2 Required quantities: Alternative definition of fluence

The fluence can also be defined by the track-length density (= track-length per volume) of particles at a point in space within a small volume:

)r(dL

)r( = Φ

dV

The fluence at a point P is numerically equal to the expectation value of the sum of the particle track lengths (assumed to be straight) that occur in an infinitesimal volume dV at P divided by dV

Chilton 1978, Health Physics 34 , 715

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