5.3.16. Surface definition source

This source type generates particles from specified surfaces. In the surface source, the surface normal at the source generation point is regarded as the z-axis, and the direction cosine is defined with respect to that axis. The parameters related to this source are shown below. The order of parameters is free. Parameters with (D=***) are optional.

Table 5.3.165 suf

value	explanation
	Surface numbers from which particles are generated. Specify surfaces defined in the [surface] section. The allowed surface types are PX, PY, PZ, SO, S, SX, SY, SZ, C/X, C/Y, C/Z, CX, CY, CZ.

Table 5.3.166 cut

value	explanation
	Restriction of the source-generation region. Specify conditions using surfaces defined in the [surface] section. The syntax is similar to region definitions in the [cell] section, but : and () cannot be used.

Table 5.3.167 dir

value	explanation
(D=1.0)	Direction cosine against the normal vector to the surface at the source point.
all	Isotropic source.
data	An a-type subsection is required.

Table 5.3.168 phi

value	explanation
(D=all)	Azimuthal angle [degree].
all	Randomly selected in the range from 0 to 360 degrees.

Table 5.3.169 dom

value	explanation
(D=0.0)	Solid angle spread [degree].
-1	\(\cos^2\) bias distribution.

Table 5.3.170 e0

value	explanation
	For mono-energy source, specify the projectile energy [MeV/n]. For an energy spectrum, use e-type = instead.

Table 5.3.171 e-type

value	explanation
mono-energy source	Give the source energy [MeV/n] directly by e0.
energy spectrum	Specify the source energy distribution by e-type.

Surfaces defined in the [surface] section with the transform operator trcl should not be specified in suf and cut. On the other hand, trcl can be used in the [source] section even when s-type = 26.