Table 1:

Quantities and parameters.

Symbol	Units	Definition	Reference
A	µm2	Cross sectional area of the cell nucleus.
d	Gy	Absorbed dose per fraction.	(Bentzen et al., 2012)
D	Gy	Absorbed dose.	(ICRU, 2011)
Φ	-	Fluence (particles µm2)	(ICRU, 2011)
n	-	Number of fractions.	(Dale, 1985)
$\dot{N}$	particles min−1 µm2	Fluence rate.	(ICRU, 2011)
P(D,i)	-	P(D,i) is the percentage of cells hit by i traversals.	(Charlton and Sephton, 1991)
r	Gy h−1	Absorbed dose rate.	(ICRU, 2011)
r0	Gy h−1	Extrapolated initial dose rate.	(Howell et al., 1994)
tTotal		Time required to deliver the total absorbed dose.
tfraction		Time required to deliver a single fraction.
Ti	h	Dose rate increase half-time. Approximate time required for dose rate to increase to one-half of its maximum value.	(Howell et al., 1997b; Pasternack and Howell, 2013)
Td	h	Dose rate decrease half-time. Approximate time required for dose rate to decrease to one-half of its maximum value.	(Howell et al., 1997b; Pasternack and Howell, 2013)
Td1		Dose rate decrease half-times for the first component of the exponential decrease in dose rate.	(Rao and Howell, 1993; Howell et al., 1994; Howell et al., 1998; Solanki et al., 2017)
Td2		Dose rate decrease half-times for the second component of the exponential decrease in dose rate.	(Rao and Howell, 1993; Howell et al., 1994; Howell et al., 1998; Solanki et al., 2017)
Tp	h	Physical half-life of radionuclide