Table 1.

Minimum beam sizes at the target simulated with new nozzle design for the different combinations of beam energy and air gap length. The sizes were obtained with multiple beam source configurations. The right part of the table lists the source parametrisations used for the dose simulations.

Configuration		Minimum beam size at target		Source beam parametrisation
beam energy [MeV]	air gap [cm]	hFWHM [mm]	vFWHM [mm]	${\sigma }_x$ [mm]	${\sigma }_y$ [mm]	$x^{\prime }$ [mrad]	$y^{\prime }$ [mrad]	$r_{x{x}^{\prime }}$	$r_{y{y}^{\prime }}$
100	30	$1.67_{-0.19}^{+0.001}$	$1.65_{-0.40}^{+0.001}$	6.5	10.0	5.0	5.0	$-1$	$-1$
100	10	$0.66_{-0.11}^{+0.001}$	$0.68_{-0.11}^{+0.001}$	4.0	4.0	3.0	3.0	$-1$	$-1$
200	30	$0.87_{-0.14}^{+0.001}$	$0.85_{-0.07}^{+0.001}$	5.0	3.5	1.0	0.5	1	$-1$