1. Report from the Geant4 Radioactive Decay Mini-workshop on 3-4 March 2015 Dennis Wright 25 March 2015

2. Objectives Address open bug reports, problems, multithreading concerns Discuss new design for RDM package Plan the update and reconciliation of data in the various files now used Plan new features 2

3. Reproducibility Data divergence multiple files with slightly different data, as well as hard-coded arrays at least one cause of non-reproducibility Remedies G4NuclideTable: will read nuclide data (masses, level energies, etc.) from file instead of using hard-coded data unify database files, provide sufficient precision for level energies examine cases where truncation of strings occurs in translating data from one form to another Put photon evaporation and RDM databases in same file structure/directory 3

4. New Features Correlation of gamma angular distributions will install Jason Detweiler’s code photon evaporation code to be modified to use this also contains some useful utility classes (Legendre, general polynomial sampling, etc. Decay by proton, neutron emission Luis will implement Beta-delayed neutrons and spontaneous fission Luis will implement Local energy deposit proposed by RDM process Dennis 4

5. Energy Conservation Current levels alpha decay : << 1 eV beta-/+ decay: << 1 eV IT: < 10 keV EC: < 10 keV IT, EC can be improved by including local energy deposit in RDM process (Dennis will implement) Current levels attained using Q values from database not nuclear masses investigate use of nuclear masses for fully stripped ions, atomic masses otherwise – requires modification of particle category 5

6. New Design Adopted Following critique of Hauf and Kuster: RDM decay processes now much simpler, more modularized Accomplished by removing one level of inheritance easy to add new decays New design to be extended to biased operation current biased code is old, and interwoven with unbiased code will begin separating biased from unbiased code finally, will look into using generic biasing when it is ready for use in at-rest processes 6

7. Testing System tests – rdecay01 – physics comparison reference (Michel) – rdecay02 – Michel has cleaned up – had06, testEm1 in good shape Unit tests – clean up existing, but old, unit tests in radioactivedecay/test/ directory (Dennis) – develop a common set (5 decays) of simple tests – Michel, Dennis – 60Co, 133Ba, 234 Th, beta+/EC, alpha, IC, etc. – good gamma spectrum, lifetime, are all expected species produced?, relaxed KS cuts 7

8. Validation Begin collecting data for comparison and posting on hadronic validation web pages database validation nuclide (Z,A) plots – Laurent particle spectra (beta+, beta-, alpha, etc. - Dennis, Laurent 8

9. Backup Slides 9

10. Bug fixes Re-enable atomic relaxation as default Dennis (done) No atomic relaxation is occurring after IC : fix this Dennis (done by Michel) 131XE, 60Ni, 212Po: lifetime = 0 for some intermediate states Dennis Do not normalize sum of branching ratios to 1 if the strength of some branches are missing – stop and kill if parent at rest (what about in-flight?) – Laurent, Dennis, Luciano energy non-conservation after atomic relaxation Random generator problems – Alex, Laurent, Andrea 10