1. 1 Event biasing and scoring mini-workshop Mar.19-23, 2007 SLAC Summary

2. 2 Participants JAp - John Apostolakis (VRVS) PA - Pedro Arce (VRVS) MA - Makoto Asai TA - Tsukasa Aso GC - Gabriele Cosmo AH - Alex Howard VI - Vladimir Ivancenko (VRVS) TK - Tatsumi Koi HK - Hisaya Kurashige FL - Fan Lei (VRVS) JP - Joseph Perl JT - Jane Tinslay MV - Marc Verderi (VRVS)

3. 3 Work Plan/Summary I-a By 9.0 release… Class clean-up – biasing and scoring… What to remove? (for v9.0) –Biasing VScorer and associated classes (in transportation and geometry/biasing) - AH –Dedicated Importance biasing Parallel Navigation (in transportation) - AH –Independent treatment of parallel and mass worlds (in transportation and geometry/biasing) - AH –Examples/extended/B03 – AH –MARS – MA, TK, HK »MA - notice to hadronics WG What to add? –Migrate B01 and B02 (for v9.0) - AH –De-pythonize and migrate (for v9.0) Tiara - AH –Scoring 1-D, 2-D contour: accumulated hits in a scorer displayed at the end of the run – TA, MA, JT »TA, MA - create a prototype within a couple of weeks and send it to JT for implementing its Draw() method.

4. 4 Work Plan/Summary I-b Directory structures and dependencies –Create processes/biasing (MV and MA) Clean /processes/scoring directory (AH) Create /processes/biasing (AH) Move Importance/weight window biasing here from scoring (AH) Biasing function wrapper for physics or generic should sit here in future (AH, JT, MA) In /processes/biasing/test should have all the tests and prototype examples –Make use of Tatsumi’s statistical scoring class which is being introduced by v9.0. For now it goes to /globals/HEPNumeric/.

5. 5 Workplan II - documentation, traceability and examples For v9.0 –Review and update current Biasing and Scoring documentations – ALL (MV - coordinate) –Remove MARS from physics lists and documents MA communicate to Hadronics WG –Produce examples to validate/verify biasing – CPU performance, statistically consistent - ALL (MV - coordinate) Test33 to be migrated to the new parallel navigator (AH, TA) Convert SLAC tutorial example (Brems splitting) into test (JT) Maintain a list of what we have / don’t have, track each item along with decision/progress (JT, MV, MA) Create/update/collect biasing documentation for all biasing techniques we decide to have - ALL (MV - coordinate) –A dedicated chapter in toolkit developers manual Prepare conversion testing suites - TK –TK communicates with BM.

6. 6 Work Plan III-a – Geometrical Biasing Point tally/detector (SLAC expressed interest, PA, MA, TK) –Can only work for tabulated cross-section  neutron_tk (for now) (TK) –MA - communicate with PA, developers of new LEP to design point scoring (shooting “pointino”) DXTRAN (for the future, after point scoring, MA) Image projection/pin-hole (for the future once we do understand it, we shall discuss again) Related would be cross-section towards a point or a direction – see physics biasing (JT) Produce a validation example – TIARA data? (AH) –TK, MA re-try to find TIARA contacts –AH research for another tests

7. 7 Work Plan III-b – Physics biasing General framework (slide 2) for accessing and modifying the required information, then associated algorithms produced for: –Bremsstrahlung Splitting - JT –Implicit capture - JT –Leading particle biasing - JT –Interaction forcing - JT –Path length biasing - JT –Cross-section biasing - JT Generic biasing process framework –access to list of physics (processes EM, hadronic interaction or model (e.g. neutron_hp)) and geometry of significance (G4GeometryCell) Wrap the function to get combined GPIL (all physics processes) Relevant to Importance Biasing and Physics Biasing (cross-section towards a point, interaction length biasing) –Work through a couple of examples to test feasibility Before September Collab. Meeting JT, HK, MA work for prototypes

8. 8 Work Plan III-c - Scoring Increase the modifiers - TA –First, clarify the concept of modifier. –Then provide examples. New scorers for residual nuclei – TA, MA –Document for hadronic elastic process New scorers with physics table (DPA) – TA, MA, TK, HK –We need ENDF atomic data / code –Wait to LLNL for their alternative 1-D, 2-D contour – TA, MA, JT, JAl New implementation of G4THitsMap –Currently each hit map has a map between copy number and physics quantity – unnecessary duplication – memory waste – TA, MA Reaction rate by process counter – TA

9. 9 TalliesMCNPXGEANT4FLUKAMARSPHITS Standard Flux Volume Surface Point/ring Current Charge Kinetic energy Particle density Reaction rates Energy dep. Rapidity DPA Momentum Pulse-height Termination Modifiers Yes No Some No Yes Partial 10 Yes No Yes No Yes ?? Yes User input ?? 3 Yes No Yes No Star (inelastic) Yes ?? 2 Yes Yes (neutrons) Yes No Yes Yes. ?? Yes No ?? 2 Yes No Yes No Yes No ?? No Yes 2 Special Mesh Coincidence Residuals Event logs rec, cyl, sph Yes Arbitrary (USER) No Yes rec, cyl Yes rec, cyl, sph Yes rec,cyl Yes Convergence Tests10Error Review of Monte Carlo All-Particle Transport Codes and.. G. W. McKinney (Los Alamos National Laboratory) et al, FNDA 2006, Cape Town, South Africa, April 3-6, 2006 >11 >1

10. 10 TalliesMCNPXGEANT4FLUKAMARSPHITS ViewerBuilt-in: 1-D, 2-D Contour External: IDL Tecplot GNUplot PAW Built-in: No External: Everything Built-in: No External: PAW ROOT Built-in: Custom External: PAW Built-in: Angel External: Angel Variance Reduction Population control Region biasing Weight cutoff Weight window mesh Energy biasing Yes No Yes Modified sampling Source biasing Implicit capture Exp. transform Production biasing Yes Yes (GPS) No Yes No Yes No Yes DXTRANYesNo Viewer2-D contourNo Immediate development (for v9.0) Medium term (1~2 years) Longer term (>2 years)