PHITSBasic Lecture II:
Definition of Tally
Multi-Purpose Particle and Heavy Ion Transport code System
title 1
Oct. 2014 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
What is Tally?
Introduction and usage of “Tally” How to use Tally for checking geometry How to use Tally for calculating physical
quantities
Kinds of TallySummary
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
Kinds of Tally in PHITS 6
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…
Visualize Particle Trajectory
method of track detection 7
x-axis
z-axis
method of track detection 8
x-axis
z-axis
Visualize Particle Trajectory
method of track detection 9
x-axis
z-axis
Visualize Particle Trajectory
method of track detection 10
x-axis
z-axis
Visualize Particle Trajectory
method of track detection 11
x-axis
z-axis
Visualize Particle Trajectory
Contents of Lecture II
Contents 12
What is Tally?
Introduction and usage of “Tally” How to use Tally for checking geometry How to use Tally for calculating physical
quantities
Kinds of TallySummary
Geometry Check
Tally for checking geometry 13
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!
Exercise 1
14
Confirm the geometry of lec02.inp in 2 dimensions using [t-gshow] tally.
Tally for checking geometry
[ M a t e r i a l ]mat[1] 1H 2 16O 1
・ ・ ・ ・ ・ ・
[ 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
A water cylinder with a radius of 10 cm and a height of 50 cm.
lec02.inp
50 cm
10 c
m
• Copy & paste 2 [t-gshow] sections from t-gshow.inp.• Set icntl=7 in [parameters] section and execute PHITS.
Answer 1
15Tally for checking geometry
lec02.inp
gshow_xz.eps
gshow_xy.eps
The height is 50cm.
The radius is 10cm.
[ P a r a m e t e r s ] icntl = 7・ ・ ・ ・ ・ ・
[ T - G s h o w ]・ ・ ・ ・ ・ ・ axis = xyfile = gshow_xy.outoutput = 6epsout = 1
[ T - G s h o w ]・ ・ ・ ・ ・ ・ axis = xzoutput = 6 file = gshow_xz.outepsout = 1
Confirm the geometry of lec02.inp in 2 dimensions using [t-gshow] tally.
xy-plane
xz-plane
How is this geometry shown in 3 dimensions?
Exercise 2
16Tally for checking geometry
gshow_xy.eps gshow_xz.eps
Confirm the geometry of lec02.inp in 3 dimensions using [t-3dshow] tally.
• Copy & paste [t-3dshow] section from t-3dshow.inp.• Set “icntl=11” in [parameters] section and execute
PHITS.
17Tally for checking geometry
lec02.inp
[ P a r a m e t e r s ] icntl = 11・ ・ ・ ・ ・ ・
[ 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・ ・ ・ ・ ・ ・
3dshow.eps
X
Y
Z・
Answer 2Confirm the geometry of lec02.inp in 3 dimensions using [t-3dshow] tally.
Parameters used in [t-3dshow]
18
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
Tally for checking geometry
19
lec02.inp
Exercise 3
Tally for checking geometry
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
[ T - 3 D s h o w ] output = 3 x0 = 0 y0 = 0 z0 = 20 e-the = 135 $ 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
[ T - 3 D s h o w ] output = 3 x0 = 0 y0 = 0 z0 = 20 e-the = 135 $ eye e-phi = 45 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
Rotate azimuthal angleof eye-point by 45 deg
X
Y
Z
“Heaven” is Y direction
Rotate zenith angle of eye-point by 45 deg
Let’s rotate the picture.
Contents of Lecture II
Contents 20
What is Tally?
Introduction and usage of “Tally” How to use Tally for checking geometry How to use Tally for calculating physical
quantities
Kinds of TallySummary
How to define Tally
Tally for calculating physical quantities
21
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 …
22
[ T - T R A C K ] title = Track Detection in xyz mesh mesh = xyz x-type = 2 nx = 25 xmin = -25. xmax = 25.y-type = 2 ny = 25 ymin = -25. ymax = 25. z-type = 1 nz = 1 -5.0 5.0e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = xy file = track_xy.out part = all gshow = 1 epsout = 1
Tally for calculating physical quantities
Example of [t-track] tally (in t-track.inp).
Geometrical mesh
Particle type
Unit of output
Output form
• [T-track]: Tally for calculating track-length or flux of particles in certain regions
[T-track] can be used for visualizing particle trajectories by setting small mesh for tallying region
Exercise 4
23
Confirm particle fluence using [t-track] tally.
How is the behavior of the particles?
[ S o u r c e ] s-type = 1 proj = 12C dir = 1.0 r0 = 2.5 z0 = -10. z1 = -10. e0 = 250.
lec02.inp
A carbon beam of 250MeV/u
Tally for calculating physical quantities
• Copy & paste 2 [t-track] sections from t-track.inp.• Set “icntl=0” in [parameters] section and execute
PHITS.
24
lec02.inp
Tally for calculating physical quantities
Answer 4
[ P a r a m e t e r s ] icntl = 0・ ・ ・ ・ ・ ・
[ T - T r a c k ]・ ・ ・ ・ ・ ・ axis = xy file = track_xy.out part = all gshow = 1 epsout = 1
[ T - T r a c k ]・ ・ ・ ・ ・ ・ axis = xz file = track_xz.out part = all gshow = 1 epsout = 1
Output file
Making an eps file using name specified by “file=”.
(***.out → ***.eps)
•In the case of 2D-plot, error files (_err.eps) are made.
Confirm particle fluence using [t-track] tally.
25
lec02.inp
Tally for calculating physical quantities
[ P a r a m e t e r s ] icntl = 0・ ・ ・ ・ ・ ・
[ T - T r a c k ]・ ・ ・ ・ ・ ・ axis = xy file = track_xy.out part = all gshow = 1 epsout = 1
[ T - T r a c k ]・ ・ ・ ・ ・ ・ axis = xz file = track_xz.out part = all gshow = 1 epsout = 1
track_xz.eps
track_xy.eps
A carbon beam of 250MeV/u with a radius of 2.5cm
Answer 4Confirm particle fluence using [t-track] tally.
26
track_xy_err.eps track_xz_err.eps
Tally for calculating physical quantities
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
27
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 …
Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ mesh = xyz x-type = 2 nx = 25 xmin = -25. xmax = 25.y-type = 2 ny = 25 ymin = -25. ymax = 25. z-type = 1 nz = 1 -5.0 5.0e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = xy file = track_xy.out part = all gshow = 1 epsout = 1
28
lec02.inp
Tally for calculating physical quantities
Geometrical Mesh
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)Z-axis (z-type = 1) : nz (number of mesh) : -5.0 5.0 (Boundaries, nz+1 )
29
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)
Tally for calculating physical quantities
30
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
Tally for calculating physical quantities
Exercise 5
31
In order to look the figures more clearly, increase the number of mesh in the [t-track] tally.• Multiply nx and ny in the [t-track]
section with “axis=xy” by four.• Multiply nx and nz in the [t-track]
section with “axis=xz” by four.
Tally for calculating physical quantities
track_xz.epstrack_xy.eps
A higher resolution is needed.
32Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ mesh = xyz x-type = 2 nx = 100 xmin = -25. xmax = 25.y-type = 2 ny = 100 ymin = -25. ymax = 25. z-type = 1 nz = 1 -5.0 5.0・ ・ ・ ・ ・ ・ axis = xy file = track_xy.out part = all gshow = 1 epsout = 1
lec02.inp track_xy.eps
We can look the figure with good resolution by increase nx and ny.
Answer 5In order to look the figures more clearly, increase the number of mesh in the [t-track] tally.
33Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ mesh = xyz x-type = 2 nx = 100 xmin = -25. xmax = 25. y-type = 1 ny = 1 -5.0 5.0z-type = 2 nz = 200 zmin = -20. zmax = 80.・ ・ ・ ・ ・ ・ axis = xz file = track_xz.out part = all gshow = 1 epsout = 1
lec02.inp track_xz.eps
Answer 5In order to look the figures more clearly, increase the number of mesh in the [t-track] tally.
How to define Tally
34
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 …
Tally for calculating physical quantities
Exercise 6
35
Show the fluence of each particle separately.• Replace “part=all” in the [t-track] tally with
“axis=xz” by “part=12C proton neutron”.
Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ axis = xz file = track_xz.out part = all gshow = 1 epsout = 1
lec02.inp track_xz.eps
How are the behaviors of 12C, proton, and neutron?
36Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ axis = xz file = track_xz.out part = 12C proton neutron gshow = 1 epsout = 1
lec02.inp
12C
proton
neutron
track_xz.eps
Answer 6Show the fluence of each particle separately.
How to define Tally
37
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 …
Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ x-type = 2 nx = 100 xmin = -25. xmax = 25. y-type = 1 ny = 1 -5.0 5.0z-type = 2 nz = 200 zmin = -20. zmax = 80. e-type = 1 ne = 1 0.0 5000.0 unit = 1 axis = xz file = track_xz.out・ ・ ・ ・ ・ ・
lec02.inp
Exercise 7
38
Show the particle fluence as a function of its energy.
• Replace “axis=xz” by “axis=eng”.
• Set “e-type=2” and set ne, emin, and emax to be 100, 0, and 5000, respectively. (See “ How to Define Mesh” in 29 page.)
• Set “nx=1” and “nz=1” to reduce the number of pages of output.
• Change the output file name to “track_eng.out”.
Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ x-type = 2 nx = 1 xmin = -25. xmax = 25. y-type = 1 ny = 1 -5.0 5.0z-type = 2 nz = 1 zmin = -20. zmax = 80. e-type = 2 ne = 100$ 0.0 5000.0 emin = 0.0 emax = 5000.0 unit = 1 axis = eng file = track_eng.out・ ・ ・ ・ ・
39Tally for calculating physical quantities
lec02.inp track_eng.eps
Energy distribution of each particle
The beam energy is 250×12=3000MeV
Answer 7Show the particle fluence as a function of its energy.
in “MeV”(not MeV/n)
lec02.inp
Exercise 8
40
Change the horizontal axis to Logarithmic scale.
• Set “e-type=3” and “emin=1.0”.
Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ e-type = 2 ne = 100$ 0.0 5000.0 emin = 0.0 emax = 5000.0 unit = 1 axis = eng file = track_eng.out・ ・ ・ ・ ・
track_eng.eps
This figure is shown in linear scale.
lec02.inp
41Tally for calculating physical quantities
[ T - T R A C K ] ・ ・ ・ ・ ・ ・ e-type = 3 ne = 100$ 0.0 5000.0 emin = 1.0 emax = 5000.0 unit = 1 axis = eng file = track_eng.out・ ・ ・ ・ ・
track_eng.eps
We can confirm the low energy region in detail.
Answer 8Change the horizontal axis to Logarithmic scale.
[ T - T R A C K ] mesh = xyzAdd “reg parameter”x-type = 2 nx = 1 xmin = -25. xmax = 25. y-type = 1 ny = 1 -5.0 5.0z-type = 2 nz = 1 zmin = -20. zmax = 80. delete・ ・ ・ ・ ・ ・
lec02.inp
Exercise 9
42
Show the energy distributions on the inside and outside of the cylinder.
• Change to region mesh ( mesh = reg )
• Specify the two regions to tally; 101(inside) and 110(outside)
• Delete or comment out parameters for mesh = xyz
Tally for calculating physical quantities
[ T - T R A C K ] mesh = regreg = 101 110$ x-type = 2$ nx = 1$ xmin = -25.$ xmax = 25.$ y-type = 1$ ny = 1$ -5.0 5.0$ z-type = 2$ nz = 1$ zmin = -20.$ zmax = 80. ・ ・ ・ ・ ・ ・
lec02.inp
Answer 9
43Tally for calculating physical quantities
In water
outside
Show the energy distributions on the inside and outside of the cylinder.
Exercise 10
44
[ T - Deposit ] title = Energy deposition in xyz mesh mesh = xyz・ ・ ・ ・ ・ ・ unit = 1material = alloutput = doseaxis = xzfile = deposit.outpart = allgshow = 1epsout = 1
t-deposit.inp
Tally for calculating physical quantities
Confirm energy deposition using [t-deposit] tally.
• Copy & paste [t-deposit] section from t-deposit.inp.
• [T-deposit]: Tally for calculating deposit energy in materials
45Tally for calculating physical quantities
deposit.eps
Energy deposition by the carbon beam.
Energy deposition by the secondary particles.
Answer 10Confirm energy deposition using [t-deposit] tally.
How to define Tally
46
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 …
Tally for calculating physical quantities
[ T - Deposit ] title = Energy deposition in xyz mesh mesh = xyz・ ・ ・ ・ ・ ・ unit = 1material = alloutput = doseaxis = xzfile = deposit.outpart = allgshow = 1epsout = 1
Exercise 11
47
Change the unit of the output of the [t-deposit] tally, [MeV/cm3/source], to [Gy/source].
• Replace “unit=1” by “unit=0”.
Tally for calculating physical quantities
lec02.inp
It should be noted that when a region includes more than two materials, dose in the region does not equal to average value of the region. Example; E1/M1+E2/M2 [PHITS] ≠ (E1+ E2)/(M1+ M2) [average dose]
Calculating deposit energy in the unit of Gy=J/kg.
48Tally for calculating physical quantities
deposit.eps
The unit and its scale have changed.
[ T - Deposit ] title = Energy deposition in xyz mesh mesh = xyz・ ・ ・ ・ ・ ・ unit = 0material = alloutput = doseaxis = xzfile = deposit.outpart = allgshow = 1epsout = 1
lec02.inp
Answer 11Change the unit of the output of the [t-deposit] tally, [MeV/cm3/source], to [Gy/source].
[ T - Deposit ] title = Energy deposition in xyz mesh mesh = xyz x-type = 2 xmin = -25.00000 xmax = 25.00000 nx = 100 y-type = 1 ny = 1 -5.0 5.0 z-type = 2 zmin = -20.00000 zmax = 80.00000 nz = 200・ ・ ・ ・ ・ ・ axis = xz file = deposit.out・ ・ ・ ・ ・ ・
Exercise 12
49
Show z-distribution of the energy deposition in the water cylinder using r-z mesh.
• Replace “mesh=xyz” by “mesh=r-z” and set r-type and z-type sub-sections.
• Set radial range from 0 to 10 cm• Replace “axis=xz” by “axis=z”.
Tally for calculating physical quantities
lec02.inp
Answer 12
50Tally for calculating physical quantities
lec02.inp deposit.eps
A Bragg peak of the carbon beam is shown at z=12cm.
Show z-distribution of the energy deposition in the water cylinder using r-z mesh.
[ T - Deposit ] title = Energy deposition in xyz mesh mesh = r-z$ x-type = 2 $ xmin = -25.00000$ xmax = 25.00000$ nx = 100 r-type = 1 nr = 1 0.0 10.0 z-type = 2 zmin = -20.00000 zmax = 80.00000 nz = 200・ ・ ・ ・ ・ ・ axis = zfile = deposit.out・ ・ ・ ・ ・ ・
Exercise 13
51
Using ANGEL, change the region of y-axis in deposit.eps.
• Add “p: ymin(1e-11) ymax(1e-9)” to the 77th line of deposit.out.
• Execute ANGEL.
Tally for calculating physical quantities
Answer 13
52Tally for calculating physical quantities
The region between 10-
11and 10-9 for the vertical axis is shown.
Using ANGEL, change the region of y-axis in deposit.eps.
・・・・・・#newpage:# no. = 1 ir = 1# r = ( 0.0000E+00 - 1.0000E+01 )p: ymin(1e-11) ymax(1e-9)x: z [cm]y: Dose [Gy/source] p: xlin ylog afac(0.8) form(0.9)h: n x y(all ),hh0l n # z-lower z-upper dose r.err -2.0000E+01 -1.9500E+01 0.0000E+00 0.0000・・・・・・
deposit.out deposit.eps
Setting Angel parameters, you can adjust some conditions of graphs.
Contents of Lecture II
Contents 53
What is Tally?
Introduction and usage of “Tally” How to use Tally for checking geometry How to use Tally for calculating physical
quantities
Kinds of TallySummary
Kinds of tally in PHITS 54
Deduce physical quantity
List of All Tallies in PHITS[t-track] Track length tally definition
[t-cross] Surface crossing tally definition
[t-heat] Heat developing tally definition
[t-deposit] Deposit tally definition
[t-deposit2] Deposit2 tally definition
[t-yield] Residual nuclei yield tally definition
[t-product] Produced particle tally definition
[t-dpa] DPA tally definition
[t-let] LET tally definition
[t-sed] SED tally definition
[t-time] Time tally definition
[t-star] Star density tally definition
[t-dchain] Dchain tally definition
[t-userdefined] User defined tally definition
[t-gshow] Region surface display definition for graphical plot
[t-rshow] Physical quantity region display definition for graphical plot
[t-3dshow] 3D graphical geometry plot definition
Visualize geometry
[t-3dshow]
Kinds of tally in PHITS 55
• 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
56
[t-3dshow](for your FUN!)
Tally for checking geometry
You can rotate [t-3dshow] picture using Python softwareSee “/phits/utility/rotate3dshow” in more detail
[t-gshow]
Kinds of tally in PHITS 57
• 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]
Kinds of tally in PHITS 58
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)
[t-cross]
Kinds of tally in PHITS 59
• 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]
Kinds of tally in PHITS 60
• 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]
Kinds of tally in PHITS 61
• 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]
Kinds of tally in PHITS 62
• 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]
Kinds of tally in PHITS 63
• 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]
Kinds of tally in PHITS 64
• 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 65
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 of Lecture II
Contents 66
What is Tally?
Introduction and usage of “Tally” How to use Tally for checking geometry How to use Tally for calculating physical
quantities
Kinds of TallySummary
Summary 67
• 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 68
• 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) by set r-z mesh
Homework
Example Answer
Homework 69
Proton (up) and neutron (down) fluences
Depth-dose distribution inside (up)and outside (down) beam radius