1. Setting of various sources A
PHITS
Multi-Purpose Particle and Heavy Ion Transport code System
Setting of various sources A
Aug revised
PHITS講習会　入門実習
Title 1

2. Goal of this lecture
Transport simulation with various kinds of sources
Source with continuous energy distribution.
Simulation with two 60Co source.
Purpose 2

3. sourceA.inp Basic setup Geometry Projectile: Geometry: Tally:
150MeV proton (pencil beam with radius 1.0cm)
Water cylinder (10cm radius and 20cm thickness)
[t-track] fluence distribution
[t-cross] proton energy spectrum coming into water
Water
150MeV
Proton
Geometry
track_xz.eps
cross_eng.eps
Check Input File 3

4. Table of contents Source with energy distribution
Continuous energy distribution
Discrete energy distribution
Setup of multiple sources
RI source
Summary
PHITS講習会　入門実習
Table of Contents 4

5. Sources with energy distribution
Source energy can be defined either as mono-energetic or distributed in PHITS
Proton beam
having energy distribution
Energy distribution 5

6. How to set 1
At [source] section, set e-type subsection (Unit of energy is MeV or angstrom).
[ S o u r c e ]
totfact = 1.0
s-type = 1
proj = proton
e0 =
r0 = 1.0
z0 = -10.
z1 = -10.
dir = 1.0
[ S o u r c e ]
totfact = 1.0
s-type = 1
proj = proton
$ e0 =
r0 = 1.0
z0 = -10.
z1 = -10.
dir = 1.0
e-type = 1
ne = 2
100.0
Energy distribution 6

7. How to set ２
3 ways to specify energy distribution. （switched by e-type）
e-type=1*: Continuous distribution with integral value.
e-type=21*: Continuous distribution with differential value (particle/MeV).
e-type=8*: Discrete distribution.
* To change weight or give energy with angstrom, use other e-type .
（See Sec of the manual）
For continuous distribution (e.g. e-type=1), specify the number of energy groups (ne), bin energy (e(i)), and intensity (w(i)).
For discrete distribution (e.g. e-type=8), specify the number of energy peaks (ne), peak energy (e(i)), and intensity (w(i)).
e-type = 1
ne = n
e(1) w(1)
e(2) w(2)
・ ・ ・ ・ ・ ・
e(n) w(n)
e(n+1)
e-type = 8
ne = n
e(1) w(1)
e(2) w(2)
・ ・ ・ ・ ・ ・
e(n) w(n)
Number of e(i) is n+1 in total.
Number of w(i) is n.
(When “ne” is negative, energy distribution in each bin is uniform in [/Lethergy].)
Numbers of e(i) and w(i) are n.
Energy distribution 7

8. Exercise 1 Set proton beam with energy distribution
Bin : [0,50], [50,100], [100,150] in MeV
Intensity : 1:3:2 in ratio. (See right figure)
Add e-type subsection and set energy distribution.
Comment out the line “e0=150”.
sourceA.inp
e-type=1 format
[ S o u r c e ]
totfact = 1.0
s-type = 1
proj = proton
e0 =
r0 = 1.0
z0 = -10.
z1 = -10.
dir = 1.0
e-type =
e-type = 1
ne = n
e(1) w(1)
e(2) w(2)
・ ・ ・ ・ ・ ・
e(n) w(n)
e(n+1)
Energy distribution 8

9. Answer 1 Set proton beam with energy distribution
Bin : [0,50], [50,100], [100,150] in MeV
Intensity : 1:3:2 in ratio.
sourceA.inp
[ S o u r c e ]
totfact = 1.0
s-type = 1
proj = proton
$ e0 =
r0 = 1.0
z0 = -10.
z1 = -10.
dir = 1.0
e-type = 1
ne = 3
150.0
cross_eng.eps
The ratio of intensity is 1:3:2.
(The ratio is given in integral value for e-type=1.)
Energy distribution 9

10. Exercise 2 Change the energy bin from [100:150] to [100:200].
Change the energy range of the 3rd bin.
Check the energy distribution in the new energy bin setup.
sourceA.inp
[ S o u r c e ]
・ ・ ・ ・ ・ ・
e-type = 1
ne = 3
150.0
e-type=1 : Source intensity is given by integral value.
Energy distribution 10

11. Answer 2 Change the energy bin from [100:150] to [100:200].
sourceA.inp
[ S o u r c e ]
・ ・ ・ ・ ・ ・
e-type = 1
ne = 3
200.0
cross_eng.eps
The ratio of energy-integrated intensity in the three bins is 1:3:2.
(The ratio is 1:3:1 if it is given in per unit energy or differential value.)
Energy distribution 11

12. Exercise 3
Give the intensity ratio 1:3:2 in differential value for the energy bins [0:50], [50:100], [100:200] .
Use e-type=21.
sourceA.inp
[ S o u r c e ]
・ ・ ・ ・ ・ ・
e-type = 1
ne = 3
200.0
e-type=21 : The ratio is given in differential value.
(Choose this option to use differential spectrum.)
Energy distribution 12

13. Answer 3
Give the intensity ratio 1:3:2 in differential value for the energy bins [0:50], [50:100], [100:200] .
sourceA.inp
[ S o u r c e ]
・ ・ ・ ・ ・ ・
e-type = 21
ne = 3
200.0
cross_eng.eps
The ratio of the intensity is 1:3:2 in differential value.
(The ratio is 1:3:4 in integral value.)
Energy distribution 13

14. Table of contents Source with energy distribution
Continuous energy distribution
Discrete energy distribution
Setup of multiple sources
RI source
Summary
PHITS講習会　入門実習
Table of Contents 14

15. Source having discrete energy
Sources having more than one energy peaks such as 60Co and 134Cs can be defined in PHITS.
60Co source
60Co
60Ni b-
g (1.173MeV) 100%
g (1.333MeV) 100%
60Co emits gamma-rays at two energies (1.173 and MeV) after beta decay.
Energy distribution 15

16. Exercise 4 Simulate 60Co source. Energy distribution 16 sourceA.inp
Change the source particle from proton to photon.
Define an isotropic point source. (Change the source radius (r0) and direction (dir).)
Use e-type=8 and set the photon energies (1.173MeV and 1.333MeV) with intensity ratio of 1:1.
Set [t-cross] to tally photon fluence from 0 to 2 MeV with 10keV resolution (200 groups) . [change emax, ne, part]
[ S o u r c e ]
totfact = 1.0
s-type = 1
proj = proton
$ e0 =
r0 = 1.0
・ ・ ・ ・ ・ ・
dir = 1.0
e-type = 21
ne = 3
200.0
e-type=8 format
e-type = 8
ne = n
e(1) w(1)
・ ・ ・ ・ ・ ・
e(n) w(n)
Energy distribution 16

17. Answer 4 Simulate 60Co source. Energy distribution 17 sourceA.inp
totfact = 1.0
s-type = 1
proj = photon
$ e0 =
r0 = 0.0
z0 = -10.
z1 = -10.
dir = all
e-type = 8
ne = 2
[ T - C r o s s ]
・ ・ ・ ・ ・ ・
emin = 0.0
emax = 2.0
ne = 200
unit = 1
axis = eng
file = cross_eng.out
output = flux
part = photon
epsout = 1
cross_eng.eps
60Co source
track_xz.eps
Energy distribution 17

18. Table of contents Source with energy distribution
Continuous energy distribution
Discrete energy distribution
Setup of multiple sources
RI source
Summary
PHITS講習会　入門実習
Table of Contents 18

19. Setup of multiple source
Multiple source with different radiation types, positions, or energy distribution can be defined in PHITS.
60Co source
60Co source
60Co sources placed at right and left of target with the intensity ratio of 2:1.
Multi-source 19

20. How to set
In [source] section, set multi-source subsection starting with ”<source>=relative intensity”
Set totfact to normalize the total source intensity
Normalization factor.
If it is positive, particles are produced with the ratio of the defined intensity.
If it is negative, same number of particles are produced, and their weight is adjusted to realize the defined intensity ratio.
[ S o u r c e ]
totfact = 1.0
<source> = 2.0
s-type = 1
proj = proton
・ ・ ・ ・ ・ ・
<source> = 1.0
proj = neutron
<source> = 3.0
s-type = 2
proj = photon
Triple sources
Relative intensity of each source.
(In this case, 2:1:3 from the top.)
Multi-source 20

21. Exercise 5
Set 60Co sources at the left and right of the cylindrical water (z=-10, 40cm) with intensity ratio of 2:1.
Add <source> lines to define two sources
Put two point sources at the position z=-10 and 40cm (Change z0 and z1 to define point sources)
Define the relative intensity of the left (z=-10cm) and the right (z=40cm) source to be 2:1.
z axis
60Co source
60Co source
z=-10cm
z=40cm
Multi-source 21

22. Answer 5
Set 60Co sources at the left and right of the cylindrical water (z=-10, 40cm) with intensity ratio of 2:1.
sourceA.inp
[ S o u r c e ]
totfact = 1.0
<source> = 2.0
s-type = 1
proj = photon
$ e0 =
r0 = 0.0
z0 = -10.
z1 = -10.
・ ・ ・ ・ ・ ・
<source> = 1.0
z0 = 40.
z1 = 40.
dir = all
e-type = 8
ne = 2
track_xz.eps
Two 60Co sources.
(With intensity ratio of right:left = 2:1)
Multi-source 22

23. Table of contents Source having energy distribution
Continuous energy distribution
Discrete energy distribution
Setup of multiple sources
RI source
Summary
PHITS講習会　入門実習
Table of Contents 23

24. RI (Radioactive Isotope) source
α, β and γ radioisotope sources can be defined by simply specifying name of RI and its activity. (From PHITS2.86)
How to set.
Set e-type=28 or 29. (29 for changing weight of source.)
e-type=28 format
e-type = 28
ni = n
RI(1) A(1)
・ ・ ・ ・ ・ ・
RI(n) A(n)
norm = ***
Number of RIs.
Name of the RIs and their activity (Bq).
Option for normalization 0: (/sec), 1: (/source)
RI source 24

25. Exercise 6
Set 60Co sources of 200 and 100Bq in the left- and right-sides, respectively, by using e-type=28.
sourceA.inp
[ S o u r c e ]
totfact = 1.0
<source> = 2.0
・ ・ ・ ・ ・ ・
z1 = -10.
dir = all
e-type = 8
ne = 2
<source> = 1.0
z1 = 40.
Change e-type.
Specify 60Co of 200 and 100 Bq at z=-10 and 40 cm, respectively. (Name format is Co-60 or 60Co.)
Normalize tally results to the unit of (/sec).
In case of e-type=28, 29, set <source> to be 1.0 and totfact to be the number of <source> subsections (totfact=2.0 in this case) because the absolute activity of RIs is directly defined in Bq.
RI source 25

26. Answer 6
Set 60Co sources of 200 and 100Bq in the left- and right-sides, respectively, by using e-type=28.
sourceA.inp
[ S o u r c e ]
totfact = 2.0
<source> = 1.0
・ ・ ・ ・ ・ ・
z1 = -10.
dir = all
e-type = 28
ni = 1 Co
　　norm = 0
(continued)
<source> = 1.0
・ ・ ・ ・ ・ ・
z1 = 40.
dir = all
e-type = 28
ni = 1 Co
　　norm = 0
cross_eng.eps
Gamma spectrum of 60Co sources (1.173 & MeV) is realized. Note that the unit of these data is [1/cm2/sec], though plot axis label is [1/cm2/source].
RI source 26

27. Decay time & Daughter nuclide
γ-rays are not emitted from 137Cs without considering its daughter nuclide
137Cs
（T1/2=30.04y）
137mBa（T1/2=2.552m） b-
g (0.6617MeV) 85.1%
137Ba
γ-rays of MeV are emitted from an isomer of Ba (137mBa) after the beta decay of 137Cs
Specify decay time parameter “dtime”
30 years ago
Now
30 years later
For dtime < 0, activity at half-life x dtime prior are calculated, and then, current activities including daughter nuclides are considered
For dtime > 0, activities at dtime (sec) later including daughter nuclides are considered
137Cs: 200 Bq
137mBa: 0 Bq
137Cs: 100 Bq
137mBa: 0 Bq
137Cs: 50 Bq
137mBa: 50 Bq Cs
dtime = -1.0 Cs
dtime = 0 Cs
dtime = 30.04*365.25*24*3600
137Cs: 100 Bq
137mBa: 100 Bq
are considered as source RIs
RI source 27

28. Most RIs reach equilibrium after 10 half-lives
Exercise 7
Change 200Bq 60Co to 200Bq 137Cs, and consider the radioactive equilibrium.
Change Co-60 to Cs-137 in the first <source> subsection.
Add dtime=-10 to the subsection. (-10 is default value)
sourceA.inp
[ S o u r c e ]
totfact = 2.0
<source> = 1.0
・ ・ ・ ・ ・ ・
z1 = -10.
dir = all
e-type = 28
ni = 1 Co
　　norm = 0
dtime =
Most RIs reach equilibrium after 10 half-lives
dtime = -10 is convenient to reproduce
most of RI sources in equilibrium.
Notes
10 x half-life is not enough to reach equilibrium for some RIs whose half-life is much shorter than that of its daughter nuclide; e.g. 105Ru（T1/2 = 4.44h）→ 105Rh（T1/2 = 35.36h）
Too large dtime (e.g. dtime = ) may cause an error
RI source 28

29. Answer 7
Change 200Bq 60Co to 200Bq 137Cs, and consider the radioactive equilibrium.
sourceA.inp
[ S o u r c e ]
totfact = 2.0
<source> = 1.0
・ ・ ・ ・ ・ ・
z1 = -10.
dir = all
e-type = 28
ni = 1 Cs
　　norm = 0
dtime = -10
cross_eng.eps
MeV gamma-rays are emitted from 137mBa by defining 137Cs source.
RI source 29

30. Let’s define 137Cs β-ray source
Exercise8
Let’s define 137Cs β-ray source
Copy & paste <source> subsection for 137Cs
Change ‘proj’ in the new <source> subsection to electron
Set totfact = 3.0
Set “part = photon electron” in [t-track] & [t-cross] to see the trajectories and energy spectra of electrons as well as photons
(totfact should be always equal to the number of <source> subsections for RI source)
RI source 30

31. Answer8 RI source 31 sourceA.inp (2nd page) track_xz.eps cross_eng.eps
totfact = 3.0
<source> = 1.0
proj = photon
・ ・ ・ ・ ・ ・
ni = 1 Cs
　　norm = 0
dtime = -10
proj = electron
(2nd page)
cross_eng.eps
Continuum spectrum of β-rays
RI source 31

32. Table of contents Source having energy distribution
Continuous energy distribution
Discrete energy distribution
Setup of multiple source
RI source
Summary
PHITS講習会　入門実習
Table of Contents 32

33. Summary
Source energy distribution (continuous and discrete) can be defined by specifying e-type in the [source] section.
Multiple sources can be defined by setting <source> subsections.
α, β, γ decay sources can be defined by directly specifying the name and activity of RIs.
《休憩はさむ》
まとめ
Refer to “setting of various source B” (phits-lec-sourceB-jp.ppt) for the setup of source using “Dump data”.
Summary 33