5.3.15. Tetra-mesh source

By specifying s-type = 24, particle generation from tetrahedrons can be defined. The particles are generated uniformly from the tetrahedron assigned by tetreg. Only one cell number should be specified, and particles are generated from the tetrahedrons belonging to the universe assigned to that cell. The direction of the source can be specified by dir, phi, and dom. The parameters for the tetra-mesh source are shown below. The order of parameters is free. Parameters with (D=***) are optional. The sample input in /utility/TetraGEOM may also be helpful.

Table 5.3.159 tetreg

value	explanation
	Cell number of the universe containing the tetrahedrons. Only one cell number can be specified.

Table 5.3.160 dir

value	explanation
(D=1.0)	Direction cosine of the projectile relative to the z-axis.
all	Isotropic source.
data	An a-type subsection is required.

Table 5.3.161 phi

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

Table 5.3.162 dom

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

Table 5.3.163 e0

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

Table 5.3.164 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.

An example using s-type = 24 is shown below.

Listing 5.3.1 Example of tetra-mesh source

 1:   [ Source ]
 2:    s-type = 24
 3:      proj = proton
 4:    tetreg = 201
 5:       dir = all
 6:        e0 = 70

In this example, particles are generated uniformly from the tetrahedrons belonging to the universe assigned to the cell number 201 specified by tetreg.