Radionuclides in TGeo M Gheata 280906 Radionuclides table

Radionuclides in TGeo M. Gheata 28/09/06

Radionuclides table n n n Added support for radionuclides as elements that may compose a TGeo material/mixture: TGeo. Element. RN class Database of ~3500 radionuclides connected via decay channels (NUBASE 2003) Table of radionuclides loaded on demand: u g. Geo. Manager->Get. Element. Table()->Get. Element. RN(Int_t A, Int_t Z, Int_t iso=0) ; iso = isomeric level

Radionuclides and their decays n n Nuclide properties: A, Z, Half-life, mass excess, isomeric number and level, natural abundency, toxicity Decay channels: TGeo. Decay. Channel objects in a list stored by each radionuclide alpha, beta decays, neutron/proton emission, electron capture, isomeric transitions, spontaneous fission u Decay properties: decay type, branching ratio, Q value, parent and daughter elements, delta iso. u

Decay chains n n Having the decay chain: P->Q->R->S->. . . the time evolution of the numbers of nuclei of each type is given by the Bateman equations: The general solution: u The coefficients aij depend on li and branching ratios u Computed only for the case P 0≠ 0, Q 0=R 0=…=0 « n General case – superposition of solutions as above A functionality of TGeo. Element. RN class is to find the evolution of the population resulting from an initial radionuclide: u u TGeo. Element. RN: : Fill. Population(TObj. Array *pop, Double_t precision, Double_t normalization=1. ) The method will fill the input array with all elements in the decay tree and attach to each element a TGeo. Bateman. Sol object

Radioactive materials and mixtures n Can be made in the same way as for normal ones, but using radionuclides as components: TGeo. Material *mat = new TGeo. Material("C 14", p. Elem. C 14, density); TGeo. Mixture *mix = new TGeo. Mixture("mix", nelem, density); mix->Add. Element(p. Elem, weigth); . . . n Time evolution of the components of a material/mixture: Fill. Material. Evolution(TObj. Array *pop, Double_t precision) n Material/mixture evolved at a given moment: Decay. Material(Double_t time, Double_t precision)

Example of usage n See $ROOTSYS/tutorials/Radio. Nuclides. C Material evolution

Example (cont) Mixture evolution

Conclusion n n Support for radionuclides added in TGeo Possibility to create materials and mixtures based on these Evolution in time according Bateman equations u Possibility to produce a material derived from a radioactive one at a moment in time u Possibility to compute activity for a given decay (API will be provided soon) u