Phits Lec02 En

PHITSBasic Lecture II:

Definition of Tally

Multi-Purpose Particle and Heavy Ion Transport code System

title 1

Jun. 2013 revised

Purpose 2

Learn how to deduce various physics quantities from the PHITS simulation

Purpose of This Lecture

You can obtain this kind of results at the end of this lectureParticle fluence (left) and depth-dose distribution (right)

for the simulation condition for homework

Contents of Lecture II

Contents 3

Introduction and usage of “Tally” What is Tally? Kinds of Tally How to use Tally for checking geometry How to use Tally for calculating

physical quantities

Summary

What is Tally?

What is tally? 4

Tally: a record of the number or amount of something, especially one that you can keep adding to;[Oxford Advanced Learner’s Dictionary (7th edition), OXFORD.]

In PHITS, the word of “Tally” used for functions toDeduce physical quantities such as flux and heat,

orDepict the 2D or 3D geometry in certain area

What is tally? 5

PHITS simulates the motion of each particle using the Monte Carlo method. You can estimate their average behavior by calculating various physical quantities as flux and deposition energy in a certain region, using “Tally”

Result of [t-track] (Track-length tally)

How many particles were passed through this region? → Use “track-length” tally

Concept of Tally


Contents 6


physical quantities

Summary

Kinds of Tally in PHITS 7

Calculating physical quantity– Particle flux 　→ [t-track], [t-cross]– Heat and deposition energy → [t-heat], [t-deposit]– Secondary particles → [t-yield], [t-product]– LET or microdosimetric distribution → [t-let], [t-sed]

Checking geometry– 2-dimensional visualization → [t-gshow], [t-rshow]– 3-dimensional visualization → [t-3dshow]

Tally Types• Various tally functions are implemented in PHITS• Many physical quantities can be deduced from the

PHITS simulation by selecting appropriate tally

For example…

Kinds of tally in PHITS 8

Deduce physical quantity

Visualize geometry

List of All Tallies in PHITS

[t-3dshow]


• Tally for visualizing the geometry in 3-dimension from a viewpoint of a certain location in PHITS virtual space

• Activated only when icntl=11 in the [parameters] section

[t-gshow]


• Tally for visualizing the geometry in 2-dimension cut by certain slices

• Show region boundary, cell number, material ID etc.• Other tallies can be used for this purpose by setting

icntl=8 in the [parameters] section (see Lecture I)

[t-track]


You can visualize the trajectory of particle using [t-track] by setting small mesh for tallying regions

• Tally for calculating track-length (cm) of particles in certain regions

• Average flux (/cm2) in the region can be also deduced from this tally, dividing the track length (cm) by the volume of the region (cm3)

Visualize Particle Trajectory

method of track detection 12

x-axis

z-axis


x-axis

z-axis



x-axis

z-axis



x-axis

z-axis



x-axis

z-axis


[t-cross]


• Tally for calculating flux or current (/cm2) of particles crossing certain surfaces

• Current is simply added by 1 when a particle cross the surface, while flux is added by 1/cos()

[t-heat], [t-deposit]


• Tally for calculating deposition energy (MeV) in certain regions

• Only ionization energy losses by charged particles are scored by [t-deposit] tally → Event-by-event data can be also deduced!

• Neutron and photon doses are calculated by the Kerma approximation in [t-heat] tally

Bragg peak calculated by [t-heat] tally

[t-yield], [t-product]


• Tally for calculating the number of secondary particles generated by nuclear reactions in certain regions

• Energy or time distribution of secondary particles can be obtained from [t-product] tally

• Yield of each nuclide can be depicted on nuclear chart using [t-yield] tally

Example of [t-yield] tally

[t-dpa]


• Tally for calculating the radiation damage index DPA in certain regions

• DPA is the average number of displaced atoms per atom of a material, and is calculated from the flux multiplied with the damage cross section

Depth-DPA distribution calculated using [t-dpa]

[t-let], [t-sed]


• Tally for calculating the probability densities of deposition energy or flux in terms of LET, lineal energy (y), or specific energy (z) in microscopic sites distributed in certain regions

• Useful for radiobiological calculations

Example of [t-let] tally*SED representsSpecific Energy Distribution

[t-deposit2]


• Tally for calculating event-by-event deposition energies in two regions

• Output the contour map of their correlation• Useful for simulating experimental data obtained by

using two detectors

Example of [t-deposit2] tally

[t-dchain]

Kinds of tallies in PHITS 23

Irradiation Cooling

Time dependence of radioactivities inside water phantom irradiated by 150 MeV proton for 6 min

• Tally for generating the input files for DCHAIN-SP, which can calculate the time evolution of the radioactive nuclides during and after irradiation

• DCHAIN-SP is also included in the PHITS package


Contents 24


physical quantities

Summary

Geometry Check

Tally for checking geometry 25

Every time you construct new geometry, it is better to check the geometry using [t-3dshow] or [t-gshow]

Otherwise you would obtain wrong results without noticing miss-definition of the geometry, especially when you make an overlapping region!

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[ P a r a m e t e r s ] icntl = 11・・・・・・

[ M a t e r i a l ]mat[1] 1H 2 16O 1

[ M a t N a m e C o l o r ] mat name color 1 Water pastelblue

[ S u r f a c e ] 10 so 500. 11 cz 10. 12 pz 0. 13 pz 50.

[ C e l l ] 100 -1 10 101 1 -1. -11 12 -13 110 0 -10 #101

Tally for checking geometry

lec02.inp

How to use [t-3dshow]

Activate[t-3dshow]

Water cylinder with radius 10 cm and height 50cm

3dshow.eps

X

Y

Z・

Parameters used in [t-3dshow]

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Origin (x0,y0,z0)

(e-the,e-phi,e-dst)

w-hgt(w-mnh)

w-dst

w-wdt(w-mnw)

e-dst

Picture FlameEye Point

Light source(l-the,l-phi,l-dst)

w-mnw × w-mnh ＝ #Pixel 100 × 100 (default)

PolarCoordinates

Polar coordinates

XYZ-coordinates


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lec02.inp

Rotate the Picture


3dshow.eps

[ T - 3 D s h o w ] output = 3 x0 = 0 y0 = 0 z0 = 20 e-the = 90 $ eye e-phi = 0 e-dst = 120 l-the = 90 $ light l-phi = 0 l-dst = 100 w-wdt = 50 $ window w-hgt = 50 w-dst = 30 heaven = y mirror = 0 line = 1 shadow = 2 resol = 1file = 3dshow.out title = Check geometry using [T-3dshow] tally epsout = 1


X

Y

Z・X

Y

Z


Rotate azimuthal angleof eye-point by 45 deg

X

Y

Z

“Heaven” is Y direction

Rotate zenith angle of eye-point by 45 deg

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[t-3dshow](for your FUN!)


You can rotate [t-3dshow] picture using Python software

See “/phits/utility/rotate3dshow” in more detail


[ T - G s h o w ]・・・・・・ axis = xyoutput = 6 file = xy_gshow.out title = Check geometry ・・・ epsout = 1

[ T - G s h o w ]・・・・・・ axis = xzoutput = 6 file = xz_gshow.out title = Check geometry ・・・ using [T-gshow] tally epsout = 1


[ T - G s h o w ]・・・・・・ axis = xyoutput = 6 file = xy_gshow.out title = Check geometry ・・・ epsout = 1

[ T - G s h o w ]・・・・・・ axis = xzoutput = 6 file = xz_gshow.out title = Check geometry ・・・ using [T-gshow] tally epsout = 1

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lec02.inp

[t-gshow]


Activate[t-gshow]

xz_gshow.eps

xy_gshow.eps

xy plane(z = 0cm)

xz plane(y = 0cm)

Water cylinder with radius 10 cm and height 50cm


Contents 31


physical quantities

Summary

How to define Tally

Tally for calculating physical quantities

32

What kind of physical quantity

Select type of tally: [t-track], [t-deposit] etc. in where

Select geometrical mesh: mesh= reg, xyz, r-zof what particle

Select particle type: part = neutron, proton etc. in which unit e.g. (cm/source), (1/cm2/source) etc.

Select unit: unit = 1, 2, 3 … in what output form

Select output axis: axis = eng, reg, xy, etc.

You have to determine …

33

lec02.inp [ T - T R A C K ] mesh = xyz x-type = 2 nx = 100 xmin = -25. xmax = 25. y-type = 1 ny = 1 -5.0 5.0 z-type = 2 nz = 200 zmin = -20. zmax = 80. part = all e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = xz file = xz_track_all.out gshow = 1 epsout = 1

• [T-track]: Tally for calculating track-length or flux of particles in certain regions

Example of [t-track]

[T-track] can be used for visualizing particle trajectories by setting small mesh for tallying region

If you would like to visualize particle trajectory …


Making an eps file using name specified by “file=”.(***.out → ***.eps)

Output file

In the case of 2D-plot, error files (_err.eps) are made.

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Particle trajectory for carbon 290 MeV/u beam with radius = 2.5cm

xy_track_all.eps xz_track_all.eps


Sample Results of [t-track]Set icntl=0 and execute PHITS …

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xy_track_all_err.eps

xz_track_all_err.eps

Error file (*_err.eps)• In the case of 2D-plot such as tallies with axis=xy, rz,

errors are output in another file named *_err.eps.• Warm colors indicate that relative standard errors are

large (close to 1), while cold colors mean small erros.


How to define Tally

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lec02.inp [ T - T R A C K ] mesh = xyz x-type = 2 nx = 100 xmin = -25. xmax = 25. y-type = 1 ny = 1 -5.0 5.0 z-type = 2 nz = 200 zmin = -20. zmax = 80. part = all e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = xz file = xz_track_all.out gshow = 1 epsout = 1

mesh = xyz :Define tally region according to xyz coordinates ⇒ You need to specify x-type, y-type, z-typeX-axis (x-type = 2) : xmin (minimum value) : xmax (maximum value) : nx (number of mesh)Y-axis (y-type = 1) : ny (number of mesh) : -5.0 5.0 (Boundaries, ny+1 ）

Geometrical Mesh


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e-type = 1 ne = 10 0 1 2 3 5 10 15 20 30 50 100

Replace “e” to “x” if you want to define x-mesh

e-type = 2 ne = 100 emin = 0 emax = 1000

1: Define #mesh and their boundaries

2,3: Define #mesh and their minimum & maximum values(2: linear, 3: logarithmic interval)

e-type = 3 ne = 100 emin = 0.1 emax = 5000

e-type = 4 edel = 100 emin = 0 emax = 5000

e-type = 5 edel = 1.301 emin = 0.1 emax = 5000

=log10(20)

How to Define Mesh• Mesh is a common concept used in many tallies• x-type, y-type, z-type, r-type, e-type, t-type, a-type etc.

x-axis y-axis z-axis radius energy time angle

• You can define each mesh using the following 5 types

4,5: Define interval of mesh and their minimum & maximum values(4: linear, 5: logarithmic interval)


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xyz mesh:Divide the regionsin XYZ coordinates

X

Y

Z

Z

R

Geometrical Mesh TypesThere are 3 types of geometrical mesh in PHITS

r-z mesh:Divide the regions

in Cylindrical coordinates

reg mesh:Divide the regionsin cells defined in

PHITS virtual space


40

[ T - T R A C K ] mesh = xyz x-type = 2 nx = 100 xmin = -25. xmax = 25. y-type = 1 ny = 1 -5.0 5.0 z-type = 2 nz = 200 zmin = -20. zmax = 80. part = all e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = xz file = xz_track_all.out gshow = 1 epsout = 1

[ T - T R A C K ] mesh = r-z r-type = 2 nr = 100 rmin = -25. rmax = 25.z-type = 2 nz = 200 zmin = -20. zmax = 80. part = all e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = rz file = rz_track_all.out gshow = 1 epsout = 1

1. Copy [t-track] tally2. Change to “mesh = r-z”3. Make “r-type” sub-section4. Delete “x-type” and “y-type”

sub-sections

lec02.inp

Change Geometrical Mesh


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[ T - T R A C K ] mesh = r-z r-type = 2 nr = 100 rmin = -25. rmax = 25.z-type = 2 nz = 200 zmin = -20. zmax = 80. part = all e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = rz file = rz_track_all.out gshow = 1 epsout = 1

lec02.inp



[ T - T R A C K ] mesh = r-z r-type = 2 nr = 25 rmin = 0. rmax = 25.z-type = 2 nz = 200 zmin = -20. zmax = 80. part = all e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = rz file = rz_track_all.out gshow = 1 epsout = 1

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lec02.inp



How to define Tally

43









44

Replace “part=all” by “part = 12C proton neutron”

[ T - T R A C K ] mesh = r-z r-type = 2 nr = 25 rmin = 0. rmax = 25.z-type = 2 nz = 200 zmin = -20. zmax = 80. part = all e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = rz file = rz_track_all.out gshow = 1 epsout = 1

[ T - T R A C K ] mesh = r-z r-type = 2 nr = 25 rmin = 0. rmax = 25.z-type = 2 nz = 200 zmin = -20. zmax = 80. part = 12C proton neutron e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = rz file = rz_track_12C-p-n.out gshow = 1 epsout = 1

lec02.inp

Define Particle Type


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12C

proton

neutron

lec02.inp

Define Particle Type


How to define Tally

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[ T - T R A C K ] mesh = r-z r-type = 2 nr = 1 rmin = 0. rmax = 25.z-type = 2 nz = 1 zmin = -20. zmax = 80. part = 12C proton neutron e-type = 2 ne = 100 emin = 0.0 emax = 5000.0 unit = 1 axis = eng file = eng_track_12C-p-n.out gshow = 1 epsout = 1

lec02.inp

in “MeV”(not MeV/n)

Change Output Form

1. Copy [t-track] section with r-z mesh

2. Change to “axis = eng”3. Change energy-mesh

sub-section4. Change the tallied region

into one region


48


lec02.inpChange Output Form


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LogarithmicScale

lec02.inpChange Energy Mesh


Change Z-Mesh

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[ T - T R A C K ] mesh = r-z r-type = 2 nr = 1 rmin = 0. rmax = 25.z-type = 2 nz = 2 zmin = -20. zmax = 80. part = 12C proton neutron e-type = 3 ne = 100 emin = 1.0 emax = 5000.0 unit = 1 axis = eng file = eng_track_12C-p-n.out gshow = 1 epsout = 1 angel = ymin(1e-11) ymax(1e-4)

-20≦z ＜ 30　　 and30≦z ＜ 80

lec02.inp


ANGEL parameter:To change layouts of eps figures.(See the ANGEL Manual)

Few carbon ions can reach over 30 cm depth (behind Bragg peak)

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[ T - T R A C K ] mesh = r-z r-type = 2 nr = 1 rmin = 0. rmax = 25.z-type = 1 nz = 3 -20. 0. 30. 80.part = 12C proton neutron e-type = 3 ne = 100 emin = 1.0 emax = 5000.0 unit = 1 axis = eng file = eng_track_12C-p-n.out gshow = 1 epsout = 1 angel = ymin(1e-11) ymax(1e-4)

lec02.inp

-20≦z ＜ 0　　 and0≦z ＜ 30　　 and30≦z ＜ 80

Shape peak is observed in the void region (before the entrance)

Change Z-Mesh


-20≦z ＜ 0

0≦z ＜ 30 30≦z ＜ 80

Carbon energy gradually decreases

How to define Tally

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Change Unit

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[ T - T R A C K ] mesh = r-z r-type = 2 nr = 1 rmin = 0. rmax = 25.z-type = 1 nz = 3 -20. 0. 30. 80.part = 12C proton neutron e-type = 3 ne = 100 emin = 1.0 emax = 5000.0 unit = 1 axis = eng file = eng_track_12C-p-n.out gshow = 1 epsout = 1 angel = ymin(1e-11) ymax(1e-4)

[ T - T R A C K ] mesh = r-z r-type = 2 nr = 1 rmin = 0. rmax = 25.z-type = 1 nz = 3 -20. 0. 30. 80. part = 12C proton neutron e-type = 3 ne = 100 emin = 1.0 emax = 5000.0 unit = 2 axis = eng file = eng_track_12C-p-n.out gshow = 1 epsout = 1 angel = ymin(1e-11) ymax(1e-4)

lec02.inp


Change fromunit=1(1/cm2/source) tounit=2(1/cm2/MeV/source)

Change Unit

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lec02.inp

[ T - T R A C K ] mesh = r-z r-type = 2 nr = 1 rmin = 0. rmax = 25.z-type = 1 nz = 3 -20. 0. 30. 80. part = 12C proton neutron e-type = 3 ne = 100 emin = 1.0 emax = 5000.0 unit = 2 axis = eng file = eng_track_12C-p-n.out gshow = 1 epsout = 1 angel = ymin(1e-11) ymax(1e-4)


per energy bin width(/MeV)


Contents 55


physical quantities

Summary

Summary 56

• A variety of information can be deduced from the PHITS simulation using functions called “Tally”

• 2 types of tallies are implemented in PHITS, one is for visualizing PHITS geometry, and the other is for calculating physical quantities

• Properness of the geometry can be checked by the tallies for its visualization: [t-3dshow] and [t-gshow]

• For defining tally, you have to determine …

Summary

what kind of physical quantity in where of what particle in which unit in what output form

Homework 57

• Depict the neutron and proton fluences, respectively, in your homework study

• Adjust [t-deposit] to see the Bragg peak of proton

• Change the minimum & maximum values of y axis in the graph for the depth-dose distribution (use “angel” parameters)

• Investigate the difference of the depth-dose distributions between the inside and outside of beam center (within the radius of 2.5cm or not)

Homework

Example Answer

Homework 58

Proton (up) and neutron (down) fluences

Depth-dose distribution inside (up)and outside (down) beam radius

Documents

Phits Lec02 En