New formula for description of positron implantation profile in condensed matter

Traditionally, it is considered that implantation profile of positrons emitted form the radioactive source is expressed by the exponential function. The Monte Carlo simulations supported by experiments indicate that the profile exhibits more complex shape. In the presented paper we proposed the new, simple mathematical formula which allows describing the profile with a good accuracy. Only two phenomenological parameters and the energy spectrum of the implanted positrons are needed for the description of the profile. Their values were found for dozen of materials for the positron emitted from the Na-22 and Ge-68\Ga-68 sources. (c) 2007 Elsevier B.V. All rights reserved.