PDSW: A program for the calculation of photon energy distribution resulting from radioactive elements in seawater

Photons, when emitted from radioactive sources in seawater, are subsequent to multiple scattering mechanisms, namely the photoelectric effect, the Compton scattering and the pair production effect. Thus, the monoenergetic emission of photons in seawater will result in equilibrium in a distribution of photons with different energies. PDSW is a MATLAB program which calculates this distribution and can be found useful for the characterization of measured spectra obtained by gamma detectors such as NaI(Tl). PDSW has been developed as an autonomous MATLAB function in order to make possible to integrate it in other applications. All calculations are performed using a typical value for seawater salinity (3.5%).

Program summary

Title of program: PDSWCatalogue identifier: ADWWProgram summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWWProgram obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandComputer: x86Operating systems: WindowsProgramming language used: MATLABMemory required: 10 MbNumber of bits in a word: 32Number of processors used: 1Vectorized or parallelized?: noNumber of bytes in distributed program, including test data, etc.: 16 378Number of lines in distributed program, including test data, etc.: 3004Distribution format:tar.gzCPC Program Library subprograms used: noneNature of physical problem: Calculation of photon energy distribution in seawater taking into account the photoelectric effect, the Compton scattering and the pair production effect.Method of solution: Analytical calculation of the continuity equation for photon energy distribution in seawater and numerical integration of this equation in equilibrium.Restrictions on the complexity of the program: Very small resolution results in large memory requirements and high execution time.Typical running time: (Maximum energy-minimum resolution) 20 sUnusual features of the program: none