1. Title Nuclear Reaction Models in Particle and Heavy Ion Transport code System PHITS Koji Niita: RIST, Japan Tatsuhiko Sato, JAEA, Japan Hiroshi Iwase: KEK, Japan Yousuke Iwamoto, Norihito Matsuda, Yukio Sakamoto, Hiroshi Nakashima: JAEA, Japan Davide Mancusi, Lembit Sihver: Chalmers, Sweden

2. contents Contents (1) Overview of PHITS (2) Application Fields of PHITS (3) Nuclear Reaction Models in PHITS (4) Event Generator

3. PHITS(1) PHITS : Particle and Heavy Ion Transport code System PHITS is a multi-purpose 3D Monte Carlo transport code system for all particles and Heavy ions with all energies from meV up to 200 GeV. 5 major codes for all particle transport in a world MCNPXGEANT4FLUKAMARSPHITS Lab. Affiliation LANLCERN,IN2P3 INFN,KEK,ESA, SLAC,TRIUMF CERN INFN FNALJAEA,RIST GSI,KEK Chalmers Univ. LanguageFortran 90/CC++Fortran 77Fortran 95/CFortran 77 Release Format Source & binary BinarySource & binary Users~2000~1000 220 Parallel Exec.Yes NoYes

4. Application Fields of PHITS Space Technology Cancer Therapy J-PARC Spallation Neutron Source Neutron Optics Heavy Ion Facilities BNCT Proton and Heavy Ion Therapy Dose in Space Shuttle Atmospheric Cosmic-Ray Accelerator

5. Moderators Hg target Fe reflector Be reflector Energy Deposition Spallation (2) PHITS has been extensively used for Optimization and Shielding design around Hg target of J-PARC P HI T S for spallation neutron source in J-PARC

6. RIA Beam production area RIKEN RI Beam Factory GSI FAIR : Super-FRS facility P HI T S for High Intensity Heavy Ion facilities P HI T S for High Intensity Heavy Ion facilities

7. 48 Ca beam track 22 C track Beam stop Target RIA Beam production area Heating in whole system 4 He track

8. 3D view by PHITS P HI T S for Shielding of Proton and Carbon Therapy Facilities P HI T S for Shielding of Proton and Carbon Therapy Facilities Dose distribution

9. 3D view by PHITS CT data Voxel data Dose distribution Boron Neutron Capture Therapy at Dept. Research Reactor, JAEA JCDS (Jaeri Computational Dosimetry System) creates the Voxel data from CT and MRI data for MCNP ( PHITS ) calculation. BNCT P HI T S for planning system for radiotherapy

10. Space Radiation T. Sato and K. Niita, Radiat. Res., 166 (2006) 544 http//www3.tokai-sc.jaea.go.jp/rphpwww/radiation-protection/expacs/expacs.html Galactic Cosmic Ray Neutron spectrum in any height of atmosphere even at ground level dose map on ground level P HI T S for neutron spectrum in atmosphere

11. Physical Processes Physical Processes included in PHITS Transport between collisions Collisions with nucleus Magnetic Field Gravity Super mirror (reflection) Mechanical devices, T0 chopper External Field and Optical devices Ionization process for charge particle SPAR, ATIMA code Energy straggling Angle Straggling Nuclear Data MCNP code ENDF-B/VI, LA150, ….. Particle Induced JAM code Collisions Heavy Ion Collisions JQMD code Nuclear Reaction Models

12. Introducing JAM (Jet AA Microscopic Transport Model) Y. Nara et.al. Phys. Rev. C61 (2000) 024901 JAM is a Hadronic Cascade Model, which explicitly treats all established hadronic states including resonances with explicit spin and isospin as well as their anti-particles. We have parameterized all Hadron-Hadron Cross Sections, based on Resonance Model and String Model by fitting the available experimental data. JAM code for Hadron Nucleus Collisions up to 200 GeV JAM Au+Au 200GeV/u in cm

13. JQMD (Jaeri Quantum Molecular Dynamics) for Simulation of Nucleus-Nucleus Collisions JQMD code for Nucleus-Nucleus Collisions up to 100 GeV/u 56 Fe 800 MeV/u on 208 Pb JQMD-1 K. Niiita et.al. Phys. Rev. C52 (1995) 2620 http://hadron31.tokai-sc.jaea.go.jp/jqmd/ Analysis of Nucleus-Nucleus Collisions by JQMD

14. MCNP MCNP code for Neutron Transport below 20 MeV with Nuclear Data Monte Carlo N-Particle Transport Code System developed by Los Alamos National Lab. for Neutrons, Photons, Electrons by using Evaluated Nuclear Data, such as ENDF, JENDL, … Applications: Nuclear Criticality Safety, Radiation Shielding, Fission Reactor Design, … n-56Fe Reaction Cross Sections

15. New Feature (1) What are we doing in Monte Carlo calculations for particle transport ? MCNP type code  Solving one-body Boltzmann equation by using the evaluated nuclear data. energy is conserved in average. no correlations Only one-body observables  Simulating real phenomena by using event generators. PHITS for high energy by JAM, JQMD. treat all ejectiles of collisions. energy and momentum are conserved in each collision. Any observables Observables beyond one-body quantities are often required. Event Generator Event Generator in PHITS We have developed the event generator mode in PHITS for all energy.

16. Event Generator Mode (2) Neutron-induced semiconductor soft error SEU: single event upset Neutron 19 MeV Si Leakage of recoil nucleus from Si Deposit Energy Distribution by PHITS An example of Event Generator Mode Kerma

17. Conclusions  Particle and heavy ion transport code (PHITS) is an essential implement in design study of accelerator facilities for various purpose, in planning system for radiotherapy, and in space radiation.  Description of nuclear reactions in the code is one of the key quantity to determine the accuracy of the transport code.  Tow reaction models: JAM and JQMD and Nuclear data are employed in PHITS to describe the nuclear reactions.  Event generator combined with the nuclear reaction model and the nuclear data is necessary to describe new quantities which are related to the higher order correlations beyond one-body observables.