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Manuscript Title: kB: A code to determine the ionization quenching function Q(E) as a function of the kB parameter.
Authors: J.M. Los Arcos, F. Ortiz
Program title: KB
Catalogue identifier: ADFM_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 103(1997)83
Programming language: Fortran.
Computer: 386 PC with.
Operating system: DOS 3.1 (or later).
RAM: 72K words
Word size: 16
Keywords: Nuclear physics, Activity detection, Liquid scintillators, Ionization quenching, Detectors radiation, Electron-capture.
Classification: 17.6.

Nature of problem:
The counting efficiency of beta-emitters and electron-capture nuclides in liquid scintillation counting (LSC) systems is affected by non- radiative processes along the particle track, the so-called ionization quenching, which reduces the effective response to electrons. This effect is described by the ionization quenching function Q(E), that is evaluated through semiempirical expressions which depend on the parameter kB and the electron stopping power in the chemical compound. A good knowledge of the values of this function for the different scintillators is a powerful tool for modelling the response of LSC systems to ionizing radiation.

Solution method:
For each value of the kB parameter, the function Q(E) is evaluated according to Birks' model with the electron stopping power for radiation and collision calculated in a mesh of selected energies according to the stechiometric formula of the scintillator compound by using the single- element parameterizations from Berger and Seltzer and the sum rule. The Q(E) integral is evaluated by using a natural spline algorithm quadrature method.

Due to unreliability of experimental data, the stopping powers are not evaluated below 1 keV. An additional point corresponding to zero energy, with a null value of the subintegrand in Q(E), which would be equivalent to infinite stopping power, is adopted and included in the energy mesh in order to apply the quadrature algorithm between zero and E energy values.

Running time:
0.3 s per each kB curve, in a 66-MHz 486 system with mathematical coprocessor.