Features of PHITS3.27
PHITS development team, Apr. 2023

1

Number of PHITS users since 2019

Top 10 countries
Country#usersJapan2317

Indonesia

302

United States

224

Philippines

179

South Korea

157

France109

Malaysia

102

Argentina

98*@03/22/2023, based on the location of users’ affiliation

China

96

4,490 new users from 68 countries in four years!

Myanmar90

Number of PHITS users in each country since 2019*https://phits.jaea.go.jp/usermap/PHITS_map_userbase.html

2Map of Models Recommended to Use in PHITS
NeutronProton, Pion(other hadrons)

NucleusLow ← Energy → High

1 TeV

e- / e+Photon
1 TeV

1 TeV/uIntra-nuclear cascade (JAM)+ Evaporation (GEM)

JAMQMD+ GEM

3.0 GeV

Intra-nuclear cascade (INCL4.6) d+t
Evaporation (GEM)
200 MeV

20 MeV

Muon

3He*JENDL-4.0/HE

αQuantum
Molecular
Dynamics(JQMD)+ GEM
10 MeV/uNuclear
1 MeV
Energy loss
Data Library
1 keV ATIMA or **KURBUC/ITSART(JENDL-4.0)*Only for facility design+ (EGM)
0.01 meV**Only for microscopic simulation

VirtualPhotoNuclear
JAM/
JQMD
+GEM

EGS5EGS5oror
EPDL97200 MeV**ETSATIMA+Original

1 keVMuonicatom +Capture

PhotoNuclear
JAM/JQMD+GEM+JENDL+NRF

1 keV

**ETS

1 meV

There is no significant change since version 3.27
3Major Upgraded Features in ver. 3.31
Since version 3.27
 Model for E-M de-excitation (EBITEM) has been improved A new function to use character variables has been implemented*1)
 A new parameter “samepage” has been introduced*1)
 A new microdosimetric function has been developed in the [t-sed] tally Instruction for defining user-own “interactions” and “particles” has been
prepared and released via github ICRP voxel and mesh reference adult phantoms have been included*2)
 RI source function has become applicable to self-fission neutron sources*3)
 Usage of most memory has been changed from static to dynamicallocation*3)
 A new option to output the cross sections contained in nuclear data libraryand stopping power has been implemented in “icntl=1” mode*3)*1) Under support of NAIS Inc.
*2) Under support of ICRP and Hanyang University*3) Under support of RIST4

Major Upgraded Features in ver. 3.31
Since version 3.27
 ITSART has been upgraded to be applicable to heavy ions and befeasible to treat excitations
 A new option of [t-cross] and [t-product] to output the results as a functionof LET has been implemented*1)
 Anatally function becomes feasible to analyze the results from different
tallies*1)
 [t-produce] becomes feasible to score secondary particles generatedusing nuclear data libraries*1)
 Several bugs in [t-point] have been fixed A new function to detect geometry errors in PHIG-3D has beenimplemented*2)*1) Under support CCSE of JAEA
*2) Under support of National Maritime Research Institute5

E-M deexcitation model (EBITEM) upgrade
EBITEM ： Model for E-M (mainly gamma)deexcitation

How to use： Activated by |igamma|≧2 , which is default.
New model(EBITEM Ver. 2)

Old model (EBITEM Ver.1)• Use RIPL-3• Use neutron capture γ-rays
literature data for H-Ge, Gd, Ta、W

• Cover all nuclei by EvaluatedGamma Activation File(EGAF)• Gamma-decay only• Consider internal conversion,
Auger e-, and fluorescent X-rays

1.E-0410-4
1.E-0610-6e-(others), X(Mγ)

X-rayAugere-(LMM,LMN,LNM),

100
1.E+0010-1
1.E-01
1.E-0210-2X(Lβ,Lγ)

1.E-0310-3

1.E-0810-8e-(KLL)

1.E-0410-4-10
1.E-1010e-(KLM,KLN), X(Kα)

1.E-0510-5-12
1.E-121000

e-(KMM,KMN,KNM), X(Kβ, Kγ)
0.002
2

JEFF-3.3
EBITEM Ver.2
EBITEM Ver.1

Intensity (/reaction)

Intensity(/reaction)• Structure data is ENSDF in 2013

0.004
0.006
46Energy (keV)

0.008
8X-rays and Auger e- from 59Co-59(n,γ)

Ver.2 agrees

1.E-0610-6
1.E-0710-70246Energy (MeV)

113Cd(n,γ)

810

γ-ray spectrum
6

User-defined character
onion.inp in lec03[Material]mat[1] Au 1
set:%Au%[1 -19.32]
mat[2] H 2 O 1
set:%H2O%[2 -1.0]
mat[3] Cu 1
set:%Cu%[3 -8.93]
mat[5] C 2 H 4
set:%C2H4%[5 -0.9]
mat[6] N 8 O 2
set:%Air%[6 -1.20e-3]…
[Cell]
100 -110101 %Au% -11
102 %H2O% 11 -1212 -13
103 %Cu%
104 %H2O% 13 -14
105 %C2H4% 14 -15
106 %Air% 15 -10

How to use• Character variable can be set as
set:%Variable_Name%[character]• LARGE and small characters are distinguished(Case Sensitive!)

Important Notice• PHIG-3D is not compatible with this function• Input data after converting the character variables
are generated in a rewrite-file named *_rwt.inp• You can skip to generate *_rwt.inp by adding“$RWT=0” before the 1st section for reducing thecomputational time (effective for larger input file)• You can generate *_rwt.inp without performing
particle transport simulation by adding “$RWT=3”→ send *_rwt.inp to PHIG-3D
7

“samepage” parameter
Example: Depth-dependence of photon fluences in Al plate irradiated by １MeV photon

samepage = part
(default, before ver. 3.30）

samepage = z

1st page(zmin = 0.0)

2nd page(zmin = 1.0)

page-continue up to
the final depth region…

Display up to 20 data specified by “samepage”
parameter (in this case, z) in the same page

Direct comparison between the data for any “axis” parameter becomes feasible

8

Development of a new model in [t-sed]
Old Model
Track-structure code TRACEL (Tomita et al. 1996) δ-ray production (Butts & Katz 1967)

Output microdosimetric quantities
ε (eV), y (keV/um), z (Gy)New Model
Track-structure code ETS mode (Kai et al. 2015)
 ITSART (Ogawa et al. 2021)

Output microdosimetric quantities
ε (eV), y (keV/um), z (Gy), nion
Number of ionizations & electronic excitations→ Useful for DNA damage yield estimation

Lineal energy distribution around thetrajectory of 1 MeV/n 12C ions for watertargets with diameter of 100 nm(Sato et al. 2006, 2009)(Sato et al. submitted)

9User Defined Model (PHITS-UDM)
 Users can implement their own "interactions" and "particles".
 Those extensions are easily shared with other users.

Example1. Photons are generated by
the electron beam
(Up to this point, calculations canbe made with normal PHITS)

2. User-defined particles areproduced by a user-definedinteraction of photons with water“kf-code” can be assigned to user-definedparticles within the range:
900000 < |kf-code| < 999999

part = photon
Water（target）

part = 900000

part = nu_e

3. The user-defined particles
decay according to a specified
lifetime and branching ratio
https://github.com/sakaki-y/PHITS-UDM

Incorporation of ICRP phantoms
Voxel Model

Mesh Model

Reference adult male and female phantoms in the PHITS input format areincluded in the PHITS package, based on the approval from ICRP

/phits/sample/icrp11

Upcoming Futures
We are planning to …

 Improve the track structure mode Extension of the precise mode applicable to other elements/compounds
 Development of coupling modules connecting to material & life sciences Improve affinity to nuclear data library Benchmark test of JENDL-5.0 and photonuclear data libraries

 Develop user support functions
 Special editor for making PHITS input file Improvement of RT-PHITS

 Improve accuracy and nuclear reaction model Improvement of JQMD ver. 2.0 to be faster and more accurate Improvement in the evaluation methods for both statistical &systematic uncertainty
 Comprehensive V&V12