7.1. [ T-Track ] section

This tally can be used to obtain the fluence in any specified region. In this tally, the track length is evaluated whenever particles pass through a specified region, as shown in Fig. 7.1.1, and the sum of the track lengths in units of cm is scored. Based on this, a particle fluence in units of [1/cm^2/source] is determined by dividing the scored track lengths by the volume of the region and the number of source particles.

As an example, information on the detector response in a specified region can be obtained by utilizing this tally. Multiplying the fluence by the cross section, in units of cm^2, of the detector enables estimation of the number of counts in the response.

Fig. 7.1.1 [T-Track] tally: track length (solid line) is calculated.

Table 7.1.1 mesh

value	explanation
reg, r-z, xyz, tet	Mesh type: a mesh type subsection is required below this option.

Table 7.1.2 volume

value	explanation
(optional)	This option defines the volume for each region for reg mesh. Volume definitions are required below this option. Values defined in [volume] are used in the case of no definition. If special description such as using (  ) is used to specify a region in reg=, its internally defined region number is output in input echo when this volume subsection is not defined.
reg vol	Volume definition. For details see the [volume] section.

Table 7.1.3 iechrl

value	explanation
72 (default)	Maximum number of columns for volume input echo.

Table 7.1.4 e-type

value	explanation
1, 2, 3, 4, 5	Energy mesh. See Section 6.6.1 for mesh subsection format.

Table 7.1.5 e-unit

value	explanation
MeV (default), keV, eV, nm, A0	Unit of energy mesh. nm specifies wavelength in nanometers, A0 specifies wavelength in angstroms. For massive particles, the de Broglie wavelength is used. When using nm or A0, unit must be 1, 4, 11, or 14.

Table 7.1.6 t-type

value	explanation
1, 2, 3, 4, 5 (optional)	Time mesh. See Section 6.6.1 for mesh subsection format.

Table 7.1.7 a-type

value	explanation
1, 2, -1, -2	Angle mesh with \(\theta\) degrees of freedom for mesh=r-z. See Section 6.6.1 for mesh subsection format.

\(\theta\) degrees of freedom can be set in r-z mesh of this tally. The a-type mesh definition used to specify \(\theta\) follows the same format as in the other angle mesh cases. The \(\theta\) dependence of results can be obtained by setting axis=rad or axis=deg, where rad and deg represent \(\theta\) in radians and degrees, respectively.

Table 7.1.8 part

value	explanation
all (default), particle name	Tally particle.

Table 7.1.9 axis

value	explanation
eng, reg, x, y, z, r	x axis value of output data.
tet	x axis value of output data. This is active only with mesh=tet.
rad, deg	x axis value of output data. These are variables for \(\theta\) when mesh=r-z.
xy, yz, xz, rz	2-dimensional.
t	Time axis.

Table 7.1.10 samepage

value	explanation
(optional, D=part)	The type of data to be displayed on the same page of the image output file. Parameters that can be defined in axis can be specified.

Table 7.1.11 file

value	explanation
file name	Define output file names. This is required by each setting of axis.

Table 7.1.12 resfile

value	explanation
(optional, D=file)	Define a file name of the past tally in the restart calculation. Even if several axis parameters were defined, specify only one resfile.

Table 7.1.13 unit

value	explanation
1	[1/cm^2/source]
2	[1/cm^2/MeV/source]
3	[1/cm^2/Lethargy/source]
4	[cm/source]
11	[1/cm^2/nsec/source]
12	[1/cm^2/MeV/nsec/source]
13	[1/cm^2/Lethargy/nsec/source]
14	[cm/nsec/source]

Lethargy in unit=3 or 13 is the natural logarithmic unit of energy defined by \(\ln(E_{\rm ref}/E)\) using a reference energy \(E_{\rm ref}\) and the particle energy \(E\). Setting these units enables obtaining results in units of Lethargy, which are given as Lethargy widths, \(\ln(E_{\rm high}/E_{\rm low})\), for each energy bin in the energy mesh subsection. Here \(E_{\rm high}\) and \(E_{\rm low}\) are the maximum and minimum values of the energy bins, respectively.

Setting unit=1,2,3,11,12 or 13 produces the mean particle fluence in a specified region calculated from the sum of the track lengths per source divided by the volume of the region. Note that, for reg mesh, the volume in the [volume] section must be set. If this is not done, the particle fluence for volume=1 [cm^3], that is, the sum of the track lengths per source, is obtained. For r-z and xyz meshes, the volume is automatically calculated. Setting unit=4 or 14 produces the sum of the track lengths per source.

Table 7.1.14 factor

value	explanation
(optional, D=1.0)	Normalization factor.

Table 7.1.15 title

value	explanation
(optional)	Title.

Table 7.1.16 angel

value	explanation
(optional)	ANGEL parameters.

Table 7.1.17 sangel

value	explanation
(optional)	Special format for ANGEL parameters.

Table 7.1.18 2d-type

value	explanation
1, 2, 3, 4, 5, 6, 7	Options for 2-dimensional plot.
(optional, D=3)

Table 7.1.19 gshow

value	explanation
0 (default), 1, 2, 3, 4, 5	When mesh=xyz and axis=xy,yz,xz, region border (1), material name (2), region name (3), and LAT number (4) are plotted using this option. gshow=5 outputs only material colors in pixel style when icntl=8.

Table 7.1.20 rshow

value	explanation
0 (default), 1, 2, 3	When mesh=reg,tet and axis=xy,yz,xz, region border (1), material name (2), and region name (3) are plotted using this option. A xyz mesh section must be added below this option.

Table 7.1.21 gslat

value	explanation
2 (default)	Option to draw lattice or tetrahedral geometry boundary lines when gshow or rshow is specified.
0	Not drawing.
1	Drawing. Note that the line of voxel phantoms may not be drawn clearly.
2	Not drawing the lines in the same cell.
3	Not drawing the lines in the same material. In this case, the boundary of two adjacent cells filled with the same material is not also drawn, even if not lattice or tetrahedral geometry. When gshow>=3, cell and lattice numbers are now shown.

Table 7.1.22 x-txt

value	explanation
(optional)	\(x\) axis title.

Table 7.1.23 y-txt

value	explanation
(optional)	\(y\) axis title.

Table 7.1.24 z-txt

value	explanation
(optional)	\(z\) axis title.

Table 7.1.25 resol

value	explanation
1 (default)	This option multiplies the region line resolution by a factor of resol with the gshow or rshow option set to define the line thickness.

Table 7.1.26 width

value	explanation
0.5 (default)	The option defines the line thickness.

Table 7.1.27 trcl

value	explanation
(optional)	Coordinate transformation number or definition for r-z or xyz mesh.

Table 7.1.28 material

value	explanation
(optional)	Specify materials for scoring.
all	all is the default, same as no definition.
number of materials	To set number of materials, define the material numbers in the next line. The number of materials can be set as a negative value, in which case the specified materials are not included for scoring.
(next line)	2 5 8 Material numbers.

Table 7.1.29 volmat

value	explanation
(optional, D=9)	This option corrects the volume value for each mesh when material is defined by the xyz mesh. 0 means no correction. Value of volmat is the number of scans per one xyz mesh side.

Table 7.1.30 multiplier

value	explanation
Number of material	Multiplier for each material.
(optional)	A multiplier subsection is required below this option. See the multiplier subsection for detailed usage.

Table 7.1.31 epsout

value	explanation
0 (default), 1, 2	When epsout=1, results are plotted into eps files. The eps file is named by replacing the extension with .eps. When epsout=2, error bars are also displayed in the eps file, except for the 2-dimensional type, axis=xy, yz, xz, rz.

Table 7.1.32 bmpout

value	explanation
0 (default), 1	Generate Bitmap figure of 2-dimensional tally output. This file is named by replacing the extension with .bmp. When mesh=xyz and axis=xy, yz, xz, it is available.

Table 7.1.33 vtkout

value	explanation
0 (default), 1	Output the tally results in the xyz mesh in the input format of ParaView. This file is named by replacing the extension with .vtk. When mesh=xyz and axis=xy, yz, xz, it is available.

Table 7.1.34 vtkfmt

value	explanation
0 (default), 1	Format of output file for ParaView. 0: ascii, 1: binary.

Table 7.1.35 foamout

value

explanation

0 (default), 1, 2

When foamout=1, generate a file of outputs, numerical data, with OpenFOAM field data format. This file is named by replacing the extension with .foam. When foamout=2, generate a file of outputs, element number, center of mass x coordinate, y coordinate, z coordinate, volume, output data, relative error, with CSV format. This file is named by replacing the extension with .csv. When mesh=tet and axis=tet, it is available.

Table 7.1.36 maxangel

value	explanation
Number of part (default)	Specify the number of part shown in the eps file. This parameter limits the number of particles shown in a tally eps file, while it does not limit them in a numerical data file.

Table 7.1.37 ctmin(i)

value	explanation
(optional, D=-9999)	Minimum value for the i-th counter.

Table 7.1.38 ctmax(i)

value	explanation
(optional, D=9999)	Maximum value for the i-th counter.

Table 7.1.39 chmin(i)

value	explanation
(optional, D=-9999)	Minimum value for the i-th history-counter. This parameter cannot be specified in the batch variance mode, istdev=1.

Table 7.1.40 chmax(i)

value	explanation
(optional, D=9999)	Maximum value for the i-th history-counter. This parameter cannot be specified in the batch variance mode, istdev=1.

Table 7.1.41 stdcut

value	explanation
(optional, D=-1)	Threshold value of STD cut off.

When specifying stdcut, PHITS automatically stop the calculation depending on values of STD, standard deviation. This function is available when stdcut is positive and itall=0,1 is set in [parameters] section. When all relative values of STD of the tally result are larger than 0 and smaller than stdcut at the last of one batch, the calculation is stopped. If stdcut in two or more tally sections is set, all the results of the tally sections have to satisfy the conditions in order for the function to work.

Table 7.1.42 iextstat

value

explanation

0 (default), 1, 2

Option for extended statistical indicators. 0: Output the transition of the mean and statistical error as a function of the total history number and batch number. 1: In addition to the contents of iextstat=0, output variance of the variance, VOV, and figure of merit, FOM, as a function of the total history number and batch number, and output a statistical check sheet. 2: In addition to the contents of iextstat=1, the probability density distribution, PDF, of the tally results is output. In this case, run a test calculation to check the range of tally results, then set the output range and run the main calculation.

To output the extended statistical indicators, set itall=3 in [parameters], set the anatally subsection in the tally section, and specify iextstat. The anatally subsection should be defined between the lines of anatally start and anatally end written in the tally section. If you output a PDF with iextstat=2 and you know the range of possible tally results, specify the PDF output range with prodenmn, prodenmx, and nbproden, and run PHITS in the main calculation. If you do not know the range, please run PHITS in a test calculation mode without specifying these three parameters and check the range before proceeding to the main calculation. Note that iextstat, prodenmn, prodenmx, and nbproden should be specified outside the anatally subsection. See Section 6.10 for more details.

Table 7.1.43 prodenmn

value	explanation
(optional, D=1e-2)	Lower limit of the PDF output range.

Table 7.1.44 prodenmx

value	explanation
(optional, D=1e+2)	Upper limit of the PDF output range.

Table 7.1.45 nbproden

value	explanation
(optional, D=100)	Number of divisions in the PDF output, logarithmic scale.