Impressions from MC2005 J. Apostolakis G. Folger.

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Impressions from MC2005 J. Apostolakis G. Folger

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Conference overview About 200 participants: providers, users,.. Organisation –Plenaries on MC tools –Parallel sessions on Methods & data advancements (electron/gamma, neutron, hadron) Verification & computer implementation Applications in particular areas –Reactor, medical including dosimetry,.. Wide diversity –Several session in parallel –This summary is a personal viewpoint And relies on notes, as talk presentations not yet available

Transcript of Impressions from MC2005 J. Apostolakis G. Folger.

Page 1: Impressions from MC2005 J. Apostolakis G. Folger.

Impressions from MC2005

J. ApostolakisG. Folger

Page 2: Impressions from MC2005 J. Apostolakis G. Folger.

Talk overview

• The conference• The radiation Transport tools ‘present’• Applications• Themes and topical issues

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Conference overview• About 200 participants: providers, users, ..• Organisation

– Plenaries on MC tools– Parallel sessions on

• Methods & data advancements (electron/gamma, neutron, hadron)

• Verification & computer implementation• Applications in particular areas

– Reactor, medical including dosimetry, ..

• Wide diversity– Several session in parallel– This summary is a personal viewpoint

• And relies on notes, as talk presentations not yet available

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Codes / Tools / ToolkitSeveral teams present:• MCNP 5• MCNPX• FLUKA• GEANT4• PHITS‘Missing’• EGS (nrc/5)• Penelope • Tripoli• MARS• …

Different ‘philosophies’• MCNP 5/X, FLUKA

– Standard ‘tool’/code driven by input files

– Built-in ‘tallies’ chosen by flags

– ‘Flat’ geometries• Delineated by surfaces

– Yet more physics options being made available

• Geant4– Toolkit– Hierarchial geometry, …

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MCNP5• Neutrons, , , protons, ..• Long line of codes (60s to now) • From Los Alamos National

Laboratory– Team of 12 code developers & 4

on data– Funding from ASCI program

• Capability evolution• Great emphasis on Quality

Assurance– Revised implementation in F90

• Profit from large supercomputer facility

– Especially for validation

Traditional strengths, include• Neutron treatment using data

– For E <~ 150 MeV• Variance reduction techniquesLatest improvements• Push for proton radiography

– Extend protons up to 50 GeV• New intra-nuclear cascade as

option – INCL4 (Liege)

• New data– ENDF/B-VII

• Built-in parallelization– MPI and OpenMP

• Generating weights fast– With PARTISN code

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MCNPX• Is eXtended version of MCNP4C

– Transports 34 particle types up to TeV energies

• Uses – evaluated data libraries (p, n, -

nuclear) – Physics models where libraries

are not available– Option for crossover at 20MeV, or

as needed (some data up to 150MeV)

• Written in F90• Many options for radiation tallies,

biasing– Weight window generator– Options for sources– Pulse-height (with variance

reduction) & coincidence tallies

• Physics enhancements– CEM 2K and INCL4 (cascade), in

addition to older Bertini, HETC, Fluka, Isabel models

doppler broadening – nuclear models

• Awards for bug reports– ‘certificate’ and $$

• Support NAG/IBM/Intel f90 complr• Parallel computation

– For all particles (uses MPI)– High speedup for criticality

calculations• Future plans

– Magnetic fields– Delayed neutrons & g– CAD input with spline tracking

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7-Can HEU Test Problem

Air

HEU

Aluminum

~5% Enriched

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PHITS

• Simulate – hadron-neucleus with

E up to 200 GeV– Nucleus-nucleus from

10 MeV/n to 100 GeV/nucleon

– Transport heavy ions, hadrons & leptons

• Neutrons down to 10-5 eV

• Features – JQMD for nucleus-

nucleus using molecular dynamics

– JAM hadronic cascade– Photons, electrons

and low-energy neutrons as in MCNP4C.

From RIST, Japan

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FLUKATool known at CERN – so just a few remarks• Compare to data for -scopic data only• ‘Not a toolkit’

– Physics models are fully integrated– Self-consistent: full cross-talk between EM, hadronics, neutrons

(with effort for same level of accuracy)– Correlations preserved enabling predictivity– ‘No programming is necessary’

• Recent extensions for heavy ions• Numerous comparisons & applications

– Including CERF, TARC, ATLAS, Atmosphere, AMS, Borexino– Talks on E deposition in LHC magnets, , CERF comparisons

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Geant4

• One plenary and over 12 parallel talks• Much interest

– Applications– Methods

• Some concerns from users– Many choices available – Difficulty to get going without good guidance

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Summary - Codes

• Fewer codes represented– Missing MVP, MCP, MCBEND, TRIPOLI, EGS, ITS,

VIM, TART, …• More complex questions

– Burn-up, activation• Remove bridge between MC and depletion codes

– Correlated sources and tallies– (Anti)coincidence of events across multiple regions– Moving geometry, stochastic geometry– 2 & 3 D graphical output necessary

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Selected topics

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CAD inputH. Tsige-Tamirat

Forschungszentrum Karlsruhe• Input from STEP/IGES files

– Thinned with engineer’s help• Tool to read CAD file, process

& create MCNP input file– Uses open source CAD as

toolkit for reading– Addresses overlaps and gaps

(‘voids’)– Created in C++, using MVC

• Status– Working for realistic JET

example

• Other efforts underway– Delegating navigation to CAD

system (speed issues)– Tesselating BREP solids

From *Summary talk*• GUIs are becoming popular• CAD is making progress

– Tools to convert to solids start to appear

– Still need to achieve arbitrary surface spline NURBS

– Would like to see these tools become OpenSource

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Human phantoms

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Distributions centers

• Codes primarily available from– Radiation Safety Information Computational

Center (RSICC) http://rsicc.ornl.gov/ at Oak Ridge National Laboratory (ORNL).

– OECD / NEA (European Nuclear Energy Agency) http://www.nea.fr/ Nuclear Data Bank computer program services http://www.nea.fr/html/dbprog/

• Conditions for distributions are evolving– Personal licenses (not site as in past)

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Applications

• Significant interest in medical applications– Dedicated session on ‘Tomographic Models

for Radiation Protection dosimetry’• Reactor applications

– Several sessions – Emerging applications for Accelerator Driven

• Space applications• Much interest in CAD-input

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Other notable / novel

• Intercomparisons of ‘tools’ at times MCNP, Geant4, Fluka, data– For proton therapy applications– For accelerator driven applications

• Novel approach to MC– Using Field Programmable Gate Arrays

• for Ultra-high Speed Monte Carlo Computation– A.S.Pasciak, J.R.Ford.

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Unusual applications

• Enhanced electron and photon fluxes in thunderstorms– T. Torii (JNDI), T.

Sugita (SSL), T. Nishijima, Z.-I. Kawasaki (Osaka U) Japan

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Simulation of the Generation of EM Shower by Muon Irradiation                     

μ +(2 GeV)

Emission of massive knock-on electrons

μ- (2 GeV)

Elevation Angle: 30°, Number of HistoriesElevation Angle: 30°, Number of Histories :: 55E-FieldE-Field : : Winter Thundercloud (Tri-pole)Winter Thundercloud (Tri-pole)

Deposition energy Deposition energy in the atmosphere in the atmosphere is calculated by is calculated by using Geant4 using Geant4 code.code.

Muon beam

thundercloud

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Other topics from the Conference Summary Comments

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Summary- Data/libraries

• More users produce their own data• Need better QA of data• Little evidence of effort on emerging needs

– Delayed gamma, neutron– Improved secondary particle production

including correlations• Library repository, with graphics good idea

– NADS: //nuclear/llnl.gov/CNP/nads

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Summary – Physics & Methods

• New physics models continue to emerge– Users getting frustrated with too wide choices– Provide recommendations

• Methods improvements– Variance reduction with pulse-height tallies– Some tough issues remain

• Effort to speed up– Parallelism, some re-write code for this– Algorithm efficiency

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Summary - Applications• About 25% of talks• Codes need to provide results & errors

– Users need “convergence score card”– Normality checks, 2nd moment of analysis, trends

• Users training more of an issue– Codes have 100-1000 options– Users unaware of “easy” solutions

• Application work should begin with related benchmark simulation– Eliminate time consuming mistakes

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Summary - Benchmarks

• Not enough benchmark papers– Perhaps most important aspect of MC development

• Need way to gather results– Web site to post papers

• Mix “component” benchmarks with integral– Integral result can mask offsetting errors/deficiencies (

e.g. Geant4)• Develop quantitative metric for comparisons

– Standard toolkit good start, some concern as well