State-of-the-art Shielding Design and Simulations for ... · FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 2 OUTLINE •Introduction •Application Examples &

State-of-the-art Shielding Design and

Simulations for Proton, Electron and Ion Beams

Fermilab Accelerator Physics Center

Nikolai Mokhov, Fermilab

International Workshop on FFAGs

Fermilab

September 21-25, 2009

FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov2

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


INTRODUCTION

Requirements to particle transport simulation toolsand needs for physics model and calculation codedevelopments are all driven by application. Themost demanding among them are high-poweraccelerators (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 areaddressed in detailed Monte-Carlo simulations,therefore, predictive power and reliability ofcorresponding codes are absolutely crucial.


SNS & Neutrino Factory High-Power Target Buildings

Backscatt

ering

Spectrom

eter

Powder

Diffracto

meter

Magnetis

m &

Liquids

Reflectom

eters

PROTO

NS

SA

NS

Cold

Neutron

Chopper

Spectro

meter

High

Resolution

Chopper

Spectromet

er

Proposed

Spin Echo

Spectrometer

and

Fundamental

Physics

Instruments

To be Built by SNS

Project

To be Built by IDTs

Proposed by IDTs

Areas for

User and

Instrument

Support


RIB-factory & Main Injector Collimators

Design optimization via MC calculations:Prompt radiation, residual radiation (hands-onmaintenance), air, ground & sump water activation,beam-induced damage (heating, material integrity,component lifetime), etc.

Marble shells of a brand-newcollimation system at Fermilab MI

Poly mask


SPACE APPLICATIONS

Space radiation protection is one of five critical enabling technologies identifiedin the NASA Strategic Plan for human space exploration. Issues: knowledge ofgalactic, solar and trapped radiation; astronaut and electronics (SEU!) protection;weight constraints; low-dose biological effects; accuracy of particle andheavy-ion transport physics, etc.

MARS-calculatedcharge transferefficiency degra-dation in CCD:60% at the endof 4-year SNAPmission


PARTICLE INTERACTION AND TRANSPORT CODES

Only with a very reliable and accuratesimulation code based on modern physicsmodels and data can one perform computermodeling to meet the needs of theapplications described.

Five general-purpose all-particle codes,extensively used worldwide in acceleratorand space applications, are in this category.


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


neutrons protons hadrons,..,,, K

nucleusphotons

electrons

JQMD

JAM, Hadron cascade model

In progress

only transport

with dE/dx (SPAR, ATIMA)

200 GeV 200 GeV 200 GeV

100 GeV/u 100 GeV

1 GeV

1 keV

10 MeV/u1 MeV1 MeV

20 MeV

(JQMD)

(Bertini)

(JQMD)

(Bertini)

(JQMD)

thermal 0 MeV 0 MeV 0 MeV/u

GEM, Evaporation process

SPAR, ATIMA, Ionization process

MCNP

with

nuclear data

MCNP

with

nuclear data

EXAMPLE: PHISICS CAPABILITIES IN PHITS

Event Generator


CODE FEATURES

All five codes can handle very complexgeometries, have powerful user-friendly built-in GUI with magnetic field & tally viewers, andvariance reduction capabilities.

Tallies include volume and surfacedistributions (1D to 3D) of particle flux,energy, reaction rate, energy deposition,residual nuclide inventory, prompt and residualdose equivalent, DPA, event logs, intermediatesource terms, etc.


Code Multifold Structure: e.g., FLUKA & MARS


MARS15 EXCLUSIVE EVENT GENERATORS

Improved Cascade-Exciton Model code, CEM03.03,combined with the Fermi break-up model, thecoalescence model, and an improved version of theGeneralized Evaporation-fission Model (GEM2) isused as a default for hadron-nucleus interactionsbelow 3 GeV. Recent multi-fragmentation extension.

The Quark-Gluon String Model code,LAQGSM03.03 (2009), is used in MARS15 forphoton, particle and heavy-ion projectiles at a fewMeV/A to 1 TeV/A. This provides a power of fulltheoretically consistent modeling of exclusive andinclusive distributions of secondary particles,spallation, fission, and fragmentation products.


Benchmarking: NUCLIDE PRODUCTION

Bremsstrahlung (Emax=1 GeV) on gold 1 GeV/A 86Kr on 9Be


Neutron Yield from Lead Targets for Heavy-Ion Beams

20x60cm Lead Cylinder


Accurate Description of Ion dE/dx down to 1 keV

MARS15: fluctuations with correlated energy loss and Coulomb scattering

Example: Ions in Si MARS15 vs data


500 and 950 MeV/u U-238 on Stainless Steel

MARS15 and PHITS vs GSI data (2007)

Accurate description of HI dE/dx down to keV in mixtures


Stopped Muons in Uranium: exp vs MARS15

Spectrum of K Muonic X Rays in U-235 and U-238

6000 6100 6200 6300 6400 6500 6600

Energy (keV)

Co

un

ts

U-238

U-235

(A)

Spectrum of L Muonic X Rays in U-235 and U-238

2900 3000 3100 3200 3300 3400

Energy (keV)

Co

un

ts

U-238

U-235

(B)

Experimental data on- cascade in U238 an U235

MARS15


Technical Drawing Implementation MC Results

geometry

materials

calculated dose isocontours

magne

tic field

LHC MQW quadrupole in FLUKA


AUTOMATIC GEOMETRY GENERATION

It is a modern approach for acceleratorcomplexes like Tevatron, LHC and J-PARC to builda realistic model of the whole machine for multi-turn beam loss, energy deposition, activation andradiation shielding studies: read in MAD latticeand create a complete geometry and magneticfield model in the framework of such codes asFLUKA, MARS and GEANT.

The experience says that such realistic modelingtakes time and substantial efforts but always paysoff.


MAD-MARS BEAM LINE BUILDER: J-PARC 3-GeV RING

By N. Nakao


RECENT BENCHMARKING AT KEK: EP1 LABYRINTH

0 1000 200010-2010-1910-1810-1710-1610-1510-1410-1310-12

Distance from Target (cm)T

otal

Dos

e (m

Sv/

p)

EP1 Labyrinth Experiment500μm Cu Target

Experiment Data neutron+gamma BG correction (On-Off)

MARS15: Total Dose

12GeV-PQ1 Q2

500μm Cu

④ ⑤ ⑥

⑦

Courtesy: Takenori Suzuki


RECENT BENCHMARKING: 12-GeV K2K TARGET STATION

Courtesy: T. Suzukiand H. Matsumura

1 9

Nine gold foil samplesover 12 meters


MARS15 Model og J-PARC Labyrinth Tunnel from Switchyard

Access

building

Utility 1

building

Electricity

building

Emergency

tunnel

Utility 2

building

1102 1101

1103

1104

1121

1122

1123

1124

1125

1112

1113

1114

1115

11111031

1032

1033

1034

1035

1036

1037

1038

1039

1045

1044

1043

1042

1041

1046

A

A

B

B

C

C

D DT. Suzuki

13.64 GeV, 5 kW

soil

concrete

Iron

4ft

air

[mSv/h]

1 mrem/h

16.44ft

3ft

12.5ft

3ft

[mrem/h]

10 mrem/h100 mrem/h

0.1 mrem/h

0.01 mrem/h

1 rem/h

67 inch

3ft

70 inch

0.001 mrem/h

0.0001 mrem/h

< 0.5 mrem/h

< 0.1 rem/h

LCLS SHIELDING DESIGN WITH MARS15

Up to 16 GeV e-beam

By T. Sanami

10-2 10-1 100 101 102 103 10410-3

10-2

10-1

100

101

102

103

104

105

Cooling time [day]

Resi

dual

dose

rate

on c

on

tact

[mS

v/h

]

Irradiation time 1day 30day 100day

1hour

1day

1week

1month

1yr

5yr

Tungsten

Copper

13.64GeV 5kW Cu 18X0W3X0W3X0

Beam dump

Beam dump activation


SHIELDING AND RADIATION EFFECT EXPERIMENT

20 30 40 50 6010-37

10-36

10-35

10-34

10-33

10-32

Product mass number

Mas

s y

ield

s (1

/ato

m/p

roto

n)

Cu

Alcove-1

10 cm

1 m

Target

8 GeV μ+

MARS15 vs data by H. Matsumura

T972 Shielding and RadiationEffect Experiment at FNALJASMIN CollaborationShielding data and code benchmarking;targets, collimators and thick shields;radiation effects on instruments andmaterials. Started in fall 2007.

Example: Muon-induced nuclide production


Example: FRIB

A brand new project

“Facility for Rare Isotope Beams”

heavily relying on MARS15 and PHITS codes

in target and shielding designs

for up to 400 kW 400 MeV/A uranium beam


S


SUMMARY

• Nowadays, there are several Monte-Carlo codes aroundwhich allow to address most of the challenging issues in R&Dand design of radiation shielding, targets, collimators, doseto patients, nuclide production and alike for proton, electronand heavy-ion beams, with impressive results obtained overlast years.

• Results of benchmarking of those widely-used codes arequite encouraging, and in some cases helped reveal existinginconsistencies.

• Some problems/difficulties in the codes are still exist,requiring further developments.

Documents

State-of-the-art Shielding Design and Simulations for ... · FFAG Workshop, Sep. 21-25, 2009 Shielding Simulations - N. Mokhov 2 OUTLINE •Introduction •Application Examples &