Fermilab Accelerator Physics Center State-of-the-art Shielding Design and Simulations for Proton, Electron and Ion Beams Nikolai Mokhov, Fermilab International Workshop on FFAGs Fermilab September 21-25, 2009
OUTLINE • Introduction • Application Examples & Demands • General Purpose All-Particle Codes • Benchmarking (focusing on ion beams) • Advances in Code Developments • Recent Proton, Electron and Ion Beam Applications • Summary FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 2
INTRODUCTION Requirements to particle transport simulation tools and needs for physics model and calculation code developments are all driven by application . The most demanding among them are high-power accelerators (Spallation Neutron Source, J-PARC, neutrino factories), heavy-ion and ADS facilities (FRIB, FAIR, EURISOL), high-energy colliders (LHC, ILC), medical beams and space exploration. Feasibility, design and specific radiation issues are addressed in detailed Monte-Carlo simulations, therefore, predictive power and reliability of corresponding codes are absolutely crucial. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 3
SNS & Neutrino Factory High-Power Target Buildings Proposed High Spin Echo Resolution Spectrometer Chopper PROTO Powder and Spectromet NS Diffracto Fundamental er meter Backscatt Physics ering Instruments Spectrom eter Magnetis m & Liquids To be Built by SNS Reflectom Cold Project SA Areas for eters Neutron NS User and Chopper To be Built by IDTs Instrument Spectro Support meter Proposed by IDTs FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 4
FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 5
RIB-factory & Main Injector Collimators Marble shells of a brand-new collimation system at Fermilab MI Poly mask Design optimization via MC calculations: Prompt radiation, residual radiation (hands-on maintenance), air, ground & sump water activation, beam-induced damage (heating, material integrity, component lifetime), etc. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 6
SPACE APPLICATIONS MARS-calculated charge transfer efficiency degra- dation in CCD: 60% at the end of 4-year SNAP mission Space radiation protection is one of five critical enabling technologies identified in the NASA Strategic Plan for human space exploration. Issues: knowledge of galactic, solar and trapped radiation; astronaut and electronics (SEU!) protection weight constraints; low-dose biological effects; accuracy of particle and heavy-ion transport physics, etc. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 7
PARTICLE INTERACTION AND TRANSPORT CODES Only with a very reliable and accurate simulation code based on modern physics models and data can one perform computer modeling to meet the needs of the applications described. Five general-purpose all-particle codes, extensively used worldwide in accelerator and space applications, are in this category. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 8
GENERAL PURPOSE ALL-PARTICLE CODES 1. FLUKA* – since 1970, currently FLUKA-2008.3b.1, CERN & INFN 2. GEANT – since 1974, currently GEANT4-9.2, CERN, SLAC et al. 3. MARS* – since 1974, currently MARS15 (2009), FNAL 4. MCNPX – since 1994, originated from earlier MCNP, currently MCNPX-2.6.0, LANL 5. PHITS* – since 2003, currently PHITS-2.15, JAEA, RIST, KEK Particle energies from hundreds TeV (FLUKA, GEANT, MARS) down to thermal neutron energy, 10 -3 <E<10 14 eV . (*) Well tuned for ion beams. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 9
EXAMPLE: PHISICS CAPABILITIES IN PHITS photons hadrons neutrons protons nucleus electrons , , K , ,.. 200 GeV 200 GeV 200 GeV 100 GeV/u 100 GeV JAM, Hadron cascade model (JQMD) (JQMD) (JQMD) JQMD In progress (Bertini) (Bertini) GEM, Evaporation process 1 GeV SPAR, ATIMA, Ionization process MCNP 20 MeV with 10 MeV/u 1 MeV 1 MeV nuclear data Event Generator MCNP with only transport 1 keV nuclear data with dE/dx ( SPAR, ATIMA ) 0 MeV 0 MeV/u thermal 0 MeV FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 10
CODE FEATURES All five codes can handle very complex geometries, have powerful user-friendly built- in GUI with magnetic field & tally viewers, and variance reduction capabilities. Tallies include volume and surface distributions (1D to 3D) of particle flux, energy, reaction rate, energy deposition, residual nuclide inventory, prompt and residual dose equivalent, DPA, event logs, intermediate source terms, etc. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 11
Code Multifold Structure: e.g., FLUKA & MARS FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 12
MARS15 EXCLUSIVE EVENT GENERATORS Improved Cascade-Exciton Model code, CEM03.03 , combined with the Fermi break-up model, the coalescence model, and an improved version of the Generalized Evaporation-fission Model (GEM2) is used as a default for hadron-nucleus interactions below 3 GeV. Recent multi-fragmentation extension. The Quark-Gluon String Model code, LAQGSM03.03 (2009) , is used in MARS15 for photon, particle and heavy-ion projectiles at a few MeV/A to 1 TeV/A. This provides a power of full theoretically consistent modeling of exclusive and inclusive distributions of secondary particles, spallation, fission, and fragmentation products. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 13
Benchmarking: NUCLIDE PRODUCTION 1 GeV/A 86 Kr on 9 Be Bremsstrahlung (Emax=1 GeV) on gold FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 14
Neutron Yield from Lead Targets for Heavy-Ion Beams 20x60cm Lead Cylinder FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 15
Accurate Description of Ion dE/dx down to 1 keV MARS15 vs data Example: Ions in Si MARS15: fluctuations with correlated energy loss and Coulomb scattering FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 16
500 and 950 MeV/u U-238 on Stainless Steel Accurate description of HI dE/dx down to keV in mixtures MARS15 and PHITS vs GSI data (2007) FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 17
Stopped Muons in Uranium: exp vs MARS15 MARS15 Spectrum of K Muonic X Rays in U-235 and U-238 (A) U-238 Counts U-235 6000 6100 6200 6300 6400 6500 6600 Energy (keV) Spectrum of L Muonic X Rays in U-235 and U-238 (B) U-238 Counts U-235 2900 3000 3100 3200 3300 3400 Energy (keV) Experimental data on - cascade in U238 an U235 FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 18
Technical Drawing Implementation MC Results geometry materials magnetic field calculated dose isocontours FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 19 LHC MQW quadrupole in FLUKA
AUTOMATIC GEOMETRY GENERATION It is a modern approach for accelerator complexes like Tevatron, LHC and J-PARC to build a realistic model of the whole machine for multi- turn beam loss, energy deposition, activation and radiation shielding studies: read in MAD lattice and create a complete geometry and magnetic field model in the framework of such codes as FLUKA, MARS and GEANT. The experience says that such realistic modeling takes time and substantial efforts but always pays off. FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 20
MAD-MARS BEAM LINE BUILDER: J-PARC 3-GeV RING By N. Nakao FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 21
RECENT BENCHMARKING AT KEK: EP1 LABYRINTH EP1 Labyrinth Experiment 500 μ m Cu Target 10 -12 10 -13 MARS15: Total Dose Total Dose (mSv/p) 10 -14 ⑦ 10 -15 10 -16 ④ ⑤ ⑥ 10 -17 10 -18 Experiment Data neutron+gamma 10 -19 500 μm Cu BG correction (On-Off) 10 -20 0 1000 2000 Distance from Target (cm) Q1 Q2 12GeV-P Courtesy: Takenori Suzuki FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 22
RECENT BENCHMARKING: 12-GeV K2K TARGET STATION 1 9 Nine gold foil samples over 12 meters Courtesy: T. Suzuki and H. Matsumura FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 23
MARS15 Model og J-PARC Labyrinth Tunnel from Switchyard Utility 2 building 1046 T. Suzuki D D 1045 1044 A B C 1043 1042 1041 1102 1101 1111 1121 1031 1122 1032 1033 1112 1036 1034 1037 1103 1035 1038 1123 1039 1124 1113 1104 1125 Emergency 1114 tunnel 1115 Utility 1 Electricity Access building building building A B C FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 24
LCLS SHIELDING DESIGN WITH MARS15 Up to 16 GeV e-beam 13.64 GeV, 5 kW < 0.1 rem/h 0.0001 mrem/h 0.001 mrem/h 0.01 mrem/h 16.44ft soil 0.1 mrem/h Beam dump activation 1 mrem/h 10 5 10 mrem/h 3ft Residual dose rate on contact [mSv/h] 13.64GeV 5kW W W 100 mrem/h Cu 18X 0 3X 0 3X 0 10 4 Beam dump Tungsten air 10 3 < 0.5 mrem/h Iron 3ft 10 2 Copper 1 rem/h 12.5ft 4ft 10 1 1hour 10 0 1day 1week 10 -1 Irradiation time 3ft 1day 1month 70 inch 10 -2 30day 1yr 100day 5yr 10 -3 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 concrete 67 inch Cooling time [day] [mrem/h] By T. Sanami [mSv/h]
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