1 / 9

Decay Process

Decay Process. Makoto Asai (SLAC) On behalf of Hisaya Kurashige (Kobe Univ.) Geant4 Users Workshop @ SLAC Feb. 19 th , 2002. Decay process. G4Decay Class is a process which manages Decay at Rest AtRestDoIt mean life time =  Decay in Flight PostStepDoIt mean free path = c 

blake
Download Presentation

Decay Process

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Decay Process Makoto Asai (SLAC) On behalf of Hisaya Kurashige (Kobe Univ.) Geant4 Users Workshop @ SLAC Feb. 19th, 2002

  2. Decay process • G4Decay Class is a process which manages • Decay at Rest • AtRestDoIt • mean life time =  • Decay in Flight • PostStepDoIt • mean free path = c • Decay mode is given byDecay TableInformation • G4DecayTable is a list of G4VDecayChannel. • G4VDecayChannel describes each decay mode. • Branching Ratio • Daughter Particle List • Decay Kinematics given by DecayIt method

  3. Decay Channel • G4VDecayChannel is an abstract class • Its derived classes are • G4PhaseSpaceDecayChannel :phase space • G4DalitzDecayChannel :p0dalitz • G4MuonDecayChannel : m -> e nn decay • G4KL3DecayChannel :Kon semileptonic • G4NeutronBetaDecayChannel :neutron beta decay • See ‘Physics ReferenceManual’ for details of these decay modes • Users can easily define his new decay mode

  4. Class Diagram

  5. G4Decay::GPIL

  6. G4Decay::DoIt

  7. PreAssignedDecay • User can assign • Decay time • Decay modes to each primary track in its rest frame by using • PreAssignedDecayProperTime • PreAssignedDecayProducts in G4DynamicParticle • Example: Decay by Event Generator • If daughter particles are written in HEPEVT format, the parent keeps these information in PreAssignedDecayProducts • Decay time can be set by using G4PrimaryParticle::SetProperTime()

  8. Radioactive decay • Long-term (>1s) radioactive decay induced by spallation interactions can represent an important contributor to background levels in space-borne -ray and X-ray instruments, as the ionisation events that result often occur outside the time-scales of any veto pulse. • The Radioactive Decay Model (RDM) treats the nuclear de-excitation following prompt photo-evaporation by simulating the production of , -, +,  and anti-, as well as the de-excitation -rays. • The model can follow all the descendants of the decay chain, applying, if required, variance reduction schemes to bias the decays to occur at user-specified times of observation.

  9. ENSDF2 http://ie.lbl.gov/ensdf Radioactive decay Photon- evaporation Radioactive decay Ion from G4 tracking defined by A, Z, Q, nuclear and atomic excitation state Sample decay profile to determine time of decay. If stable do not process User input defines times of observation for biasing decay curve, splitting of nuclei, and nuclide decays to ignore Sample branching ratios Geant4 Tracking & process control User input defines Biasing of branching ratios Sample secondaries and commit to stack. Determine nuclear recoil. a, b, n RDM-specific user inputs Geant4 data sources Apply photonuclear de- excitation process g Geant4 simulation

More Related