Table 4.

Calculation times for different calculation parameters (6 MeV, $20\times 20\hspace{0.17em}{\text{cm}}^2$). The DCF is not used.

	Statistical Accuracy	Grid Size	Calculation Time
Fixed grid size	5%	$2\times 2\hspace{0.17em}{\text{mm}}^2$	2.60 min
	3%	$2\times 2\hspace{0.17em}{\text{mm}}^2$	7.65 min
	2%	$2\times 2\hspace{0.17em}{\text{mm}}^2$	16.95 min
	1%	$2\times 2\hspace{0.17em}{\text{mm}}^2$	68.20 min
Fixed statistical accuracy	2%	$2\times 2\hspace{0.17em}{\text{mm}}^2$	1.08 min
	2%	$2.5\times 2.5\hspace{0.17em}{\text{mm}}^2$	5.02 min
	2%	$2\times 2\hspace{0.17em}{\text{mm}}^2$	16.95 min
	2%	$1.5\times 1.5\hspace{0.17em}{\text{mm}}^2$	29.72 min