Improvements of sampling and scoringImprovements of sampling and scoring( User Requirements: Scoring for event biasing ( User Requirements: Scoring for event biasing

options)options)

Tsukasa AsoTsukasa Aso,,Toyama National College of Maritime Technology, JapanToyama National College of Maritime Technology, Japan

ContentsContents►ObjectiveObjective►Current scoring optionsCurrent scoring options►Migration from geometry biasing Migration from geometry biasing

scorerscorer►User requirementsUser requirements►SummarySummary

ObjectiveObjective► The main goal of improvements of scoring is to provide a usThe main goal of improvements of scoring is to provide a us

er with common sampling scheme under:er with common sampling scheme under: event biasingevent biasing

► Geometrical biasingGeometrical biasing► Physics process biasingPhysics process biasing

All the influences of these biasing will be reflected to the “particle weight” in All the influences of these biasing will be reflected to the “particle weight” in order to keep a consistency of the result order to keep a consistency of the result

parallel geometryparallel geometry► ParallelWorldScoringProcess has already been availableParallelWorldScoringProcess has already been available► Geometrical biasing is migrated to using parallel geometry. (by Alex)Geometrical biasing is migrated to using parallel geometry. (by Alex)

The geometry must be identified by the geometry number,The geometry must be identified by the geometry number,i.e. copy number or replication numberi.e. copy number or replication number

► Scorers must be applicable by same manner Scorers must be applicable by same manner in both of mass and parallel geometry in both of mass and parallel geometry with or without event biasingwith or without event biasing

Current scoring optionsCurrent scoring options► There are three kinds of scorersThere are three kinds of scorers

Sensitive DetectorSensitive Detector► Users have to implement own detector class and hit classUsers have to implement own detector class and hit class

MultiFunctional Detector with Primitive ScorerMultiFunctional Detector with Primitive Scorer► Geant4 provides many scorersGeant4 provides many scorers► Users can compose own scorer by combining those scorersUsers can compose own scorer by combining those scorers► Keys of maps are redundant for scorers of same volumeKeys of maps are redundant for scorers of same volume► More improvements are desirable for efficient scoringMore improvements are desirable for efficient scoring

Event biasing scorerEvent biasing scorer► Useful quantities for checking geometrical biasingUseful quantities for checking geometrical biasing► Sampling at Entering/InVolume/Exiting is useful for usersSampling at Entering/InVolume/Exiting is useful for users► Must work with geometrical event biasing Must work with geometrical event biasing ► Event biasing process becomes more simple if the scorer is sepEvent biasing process becomes more simple if the scorer is sep

arated from geometrical biasingarated from geometrical biasing► By separating the role, we can make it simpleBy separating the role, we can make it simple

Process, Process Placer, Scorer Process, Process Placer, Scorer

Migration from event biasing Migration from event biasing scorerscorer

►Geant4 provides examples at Geant4 provides examples at example/extended/biasing/B01~B03example/extended/biasing/B01~B03 B01 Mass geometryB01 Mass geometry B02 Parallel geometry, AIDAB02 Parallel geometry, AIDA B03 using PythonB03 using Python

►Test version of parallel geometry Test version of parallel geometry ( by ( by Alex )Alex ) B01_para Mass geometryB01_para Mass geometry B02_para Parallel geometryB02_para Parallel geometry

► Detail in event biasing scorerDetail in event biasing scorer default scoring quantitiesdefault scoring quantities

► Entering track G4PSTrackCounterEntering track G4PSTrackCounter► Population G4PSPopulationPopulation G4PSPopulation► Collision G4PSCollisionCollision G4PSCollision► SL G4PSTrackLengthSL G4PSTrackLength► SLW G4PSTrackLengthSLW G4PSTrackLength► SLWE G4PSTrackLengthSLWE G4PSTrackLength► SLWE_v G4PSTrackLengthSLWE_v G4PSTrackLength► SLW_v G4PSTrackLengthSLW_v G4PSTrackLength► NumWGTedE = SLWE_v/SLW_v (Run)NumWGTedE = SLWE_v/SLW_v (Run)► FluxWGTedE = SLWE/SLW (Run)FluxWGTedE = SLWE/SLW (Run)► Av.Tr.WGT = SLW/SL (Run)Av.Tr.WGT = SLW/SL (Run)

Problem in event biasing scorerProblem in event biasing scorer► Since the biasing has to access to the both of volume in geometrical boundary, Since the biasing has to access to the both of volume in geometrical boundary,

Scoring in given function basically stores quantities for “poststep” volume.Scoring in given function basically stores quantities for “poststep” volume.► It should be unified to the volume of “prestep”It should be unified to the volume of “prestep”

ScoreAnExitingStep(aStep,pre_gCell)ScoreAnExitingStep(aStep,pre_gCell) ScoreAnEnteringStep(aStep,post_gCell)ScoreAnEnteringStep(aStep,post_gCell) ScoreAnInVolume(aStep, post_gCell)ScoreAnInVolume(aStep, post_gCell)

► To use the volume in “poststep” causes miss the sampling step information.To use the volume in “poststep” causes miss the sampling step information. At the geometry boundaryAt the geometry boundary At the world volume boundaryAt the world volume boundary

=>This is mentioned in User’s manual. “Scoring cells must not share boundaries with t=>This is mentioned in User’s manual. “Scoring cells must not share boundaries with the world volume.” he world volume.”

1

1x

B01B01

18 slabs(cell_01 ~ cell_18)

1 slab for score(rest_rep)

+-100cm

10 MeV neutron

WorldVolume (shieldWorld)

R=100cm

Mass geometry Importance / Scoring

► For comparison, PS are created for reproducing the event biFor comparison, PS are created for reproducing the event biasing scorer. ( B01 )asing scorer. ( B01 )i.e. use “prestep/poststep” volume in some case.i.e. use “prestep/poststep” volume in some case.

Completely same result

Copy number of volumes are assigned for primitive scorer

► Difference comes from Difference comes from boundary identification of volumes boundary identification of volumes steps to the out of world volume.steps to the out of world volume.

Regular scoring using prestep volume (B01_para)

InVolume quantities are same.Boundary related quantities are different

B02_paraB02_para

R=101cmR=100cmＺ=+- 90cmMass

Para

10cm thick slab

In parallel geometryIn parallel geometry► Importance/PS are attached to same parallel geometryImportance/PS are attached to same parallel geometry

Here I changed G4ParallelWorldScoringProcess:CopyStep(const G4Step) for settinggeometry boundary of PreStepPoint.

ImportanceImportance

MassMass ParallelParallel

ScoringScoring MassMass △△

ParallelParallel11

△△ ○○

ParallelParallel22

○○

Executed without serious problem

But result are different each otherby the choice of transportation, Transportation CoupledTransportation

Executed but the result is not same as Mass-Mass combination.

Exactly same result.But if the biasing scorer is turned off,the result of PS is changed.=> This difference come from interaction??? See next slides.

Parallel

0

1

2

3

4

5

6

7

8

9

10

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Cell ID+1

Flux

WG

TedE

w/ o bsw/ bs

When turning off the biasing scorer, the result is changed by physics interaction?

Question from biasing exampleQuestion from biasing example Every process for parallel world geometry Every process for parallel world geometry

checking and identifying the geometry checking and identifying the geometry boundary in parallel worldboundary in parallel world

Is there any possibility to merge it?Is there any possibility to merge it?i.e. a process for giving step status for the i.e. a process for giving step status for the parallel world. parallel world.

User requirements(1) ~Other User requirements(1) ~Other MC~MC~

Elemental quantities Current Flux Fluence

MCNP4B Surface current Surface Flux Cell Flux Point Flux

After MCNP4B Mesh Tally - Rectangular - Cylindrical - Spherical

After MCNP4B Mesh Tally - Track averaged (tracks, flux, dose) - Source (coincidence, anticoincidence) - Energy deposition (total, de/dx,…) - DXTRAN - Image projection - Point detector

SCORE (energy deposition of the volume)

EVENTDAT

USRBDX (surface)

USRYEILD

USRBIN (space)

EVENTBIN

USRCOLL

RESNUCLEi

USRTRACK

DETECT

Time windowCoincidence capture …

FLUKAPhysics quantitiesGeometrical condition

FM(read/store)

User requirements(2)~scorer~User requirements(2)~scorer~► The primitive scorer has been already The primitive scorer has been already

provided interest physics quantities.provided interest physics quantities.(This is because we started from MCNP tally (This is because we started from MCNP tally for primitive scorer development)for primitive scorer development)

► Current options does not involve any Current options does not involve any support to define scoring geometrysupport to define scoring geometryTally = Geometry + Sampling + ScoringTally = Geometry + Sampling + Scoring

► Scorer needs to get differential distributionsScorer needs to get differential distributionsEnergy distribution, Angular distribution,Energy distribution, Angular distribution,or double-differential distributionor double-differential distribution

User Requirements(3)User Requirements(3)UR.1 Geometry boundary can be identified by the

value of StepStatusUser can easily distinguish the step condition

EnteringStep, InVolumeStep,ExititingStep may be also helpful.

UR.2 The volume can be identified by the volume name and its copy number

User need to identify what volume should be assigned for scoring

A kind of volume ID is useful. This is important in mass geometry.

UR.3 The scorer must be extensible for implementing user hook actions

For example, user want to use AIDA inside scorer

The concept is almost same as PrimitiveScorer

UR.4 Scoring space, i.e. mesh, should be defined by UI command or helper class.(Rectangle, Cylindrical, Spherical)

User defined scoring geometry

Probably in parallel geometry.

UR.5 Surface should be defined by UI command or helper class(Rectangle, Cylindrical, Spherical)

User defined scoring geometry

Probably in parallel geometry. More sophisticated definition of surface is necessary.

UR.6 Scorers are composed and attached to the scoring geometry

more than one physical quantities can be scored in one scoring volume.

The concept is same as MultiFunctionalDetector

UR.7 A scorer may have differential distributions, so that the binning can be specified by the user.

i.e. energy distributions, energy-binned flux etc.

Current hits collection of primitive scorer has to be modified

UR.8 Data size for scored result and execution time should be as small as possible

Key of geometry index should be used commonly

Current hits collection of primitive scorer has to be modified

User Requirements(4)User Requirements(4)UR.9 Scoring results may be accessed at

the end of event or be accumulated during the RUN

i.e. energy deposit of calorimeter per a primary particle, or flux of entire run.

UR.10 A scorer can have a filter for track selection.

i.e. particles, energy window

UR.11 Source coincidence ?? Particle Gun Number?? Produced position

UR.12 Timing window ??

UR.13 Triggering ??

UR.14

UR.15

UR.16

SummarySummary►Migration from event biasing scorer to Migration from event biasing scorer to

primitive scorer will be possibleprimitive scorer will be possible Still we have to investigate the differencesStill we have to investigate the differences

►The new scoring capabilities will be The new scoring capabilities will be designed and implementeddesigned and implemented

►The some of example using new The some of example using new scorer, event biasing, and parallel scorer, event biasing, and parallel geometry will be presentedgeometry will be presented