3.11. Card 9: Calculation region details for xyz mesh geometries

Table 3.11.1 IMAT PHITS: same name

Value	Description
	The number of distinct materials present in the problem.

Table 3.11.2 MTSCORE PHITS: same name

Value	Description
(DP=0)	Select which materials will have activation assessed in them.
= 0	Evaluate activation and decay in all materials.
= N	Only evaluate activation and decay in the N\(^{th}\) material.

Card 9a: Material information listings

This card must be repeated IMAT times; each entry is on a separate line.

Table 3.11.3 MT-LIST PHITS: not settable

Value	Description
	Number of nuclides present in this material.

See Card 9b on the previous page. The nuclide composition of each material is specified by a Card 9b entry starting on the line immediately following each MT-LIST entry and should be MT-LIST lines long. \(\qquad\) (Note that MT-LIST behaves like ITGNCLS for region-wise geometries.)

Card 9c: Mesh information listings

Table 3.11.4 IMESH PHITS: not settable

Value	Description
	Total number of mesh regions (nx\(\times\)ny\(\times\)nz). [1]

Following the IMESH entry line should be a single line containing the column header names listed below followed by IMESH lines with values in each column for each mesh region. Below are listed the column headers with descriptions for what information should be provided in the respective columns in each line for each mesh region.

Table 3.11.5 NON PHITS: not settable

Value	Description
	Index of mesh region relative to all mesh regions.

Table 3.11.6 IX PHITS: other means

Value	Description
	Index of mesh region in the x-axis mesh.

Table 3.11.7 IY PHITS: other means

Value	Description
	Index of mesh region in the y-axis mesh.

Table 3.11.8 IZ PHITS: other means

Value	Description
	Index of mesh region in the z-axis mesh.

Table 3.11.9 FLUXS PHITS: not settable

Value	Description
(D=0.0, DP= automatically calculated [2], requires JMODE=1,2)	Total neutron flux below 20 MeV in [n/(cm\(^2\)\(\cdot\)sec)].

Table 3.11.10 VOLUME PHITS: not settable

Value	Description
(D=1.0, DP=automatic)	Total volume of this mesh region in [cm\(^3\)].

Table 3.11.11 VOLMATNNN PHITS: not settable

Value	Description
(D=1.0, DP=automatic)	This column should be repeated IMAT times with NNN starting as 001 and incrementing for each material. The value listed here is the volume in [cm\(^3\)] of this mesh region which is filled with each material; the sum of these VOLMATNNN values should equal VOLUME, minus whatever portion of the mesh region, if any, is in a void region.

Card 9d: 2D output plotting options for xyz mesh geometries

Requires all x, y, and z axes to have mesh type 2, 3, 4, or 5 (evenly spaced meshes; breaks if any meshes are type 1). In [T-Dchain], these variables are called IPLTMODE and IPLTAXIS (without the “o”).

Table 3.11.12 IPLOTMODE PHITS: other means

Value	Description
(D=0)	Select which axes combinations will have 2D plots made.

Table 3.11.13 IPLOTAXIS PHITS: other means

Value	Description
(D=0)	Select axis units. If IPLOTMODE is specified, this defaults to 1 instead of 0.
= 0	Grid index number.
= 1	Distance in [cm].

[1]

Note: large meshes in [T-Dchain] can require high amounts of memory in PHITS (\(\sim\)4 MB per voxel).

[2]

PHITS calculates FLUXS as amp (in source/sec, from [T-Dchain] input parameters) times the region’s total neutron flux (in n/(source\(\cdot\)cm\(^2\)) as determined by the automatically generated [T-Track] tally).