ERYAProfiling: a code for depth profiling of light elements in inhomogeneous samples by PIGE

(1) LIBPhys, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
(2) Universidade Europeia| Laureate International Universities, 1500-210 Lisboa, Portugal

ERYA (Emitted Radiation Yield Analysis) code was developed in order to implement a PIGE standard free method for thick samples [1]. To achieve this, ERYA contains a database with several nuclear reaction excitation functions which are used to calculate the corresponding gamma-ray yields. However, ERYA code is only able to analyze samples with homogeneous concentrations across the depth. Thus emerged the need to develop a new code.

This work presents the ERYAProfling code, which was developed for quantitative analysis/depth profiling of light elements by a standard-free PIGE technique in samples with inhomogeneous concentrations across the depth.

One of the main characteristic of this code is the calculation of the beam’s energy straggling in order to determine the beam’s energy distribution across the sample. The beam’s energy straggling is implemented based on theoretical models. For relatively large depth the beam’s energy straggling is described by a Gaussian distribution. For relatively low depth the beam’s energy straggling is described by Landau or Vavilov's distributions. For the calculation of the beam's energy distribution, the beam's natural resolution and the Doppler's thermal broadening are also accounted for.
To calculate the gamma-ray yield from each depth the code uses the corresponding excitation function (which is stored in a user-editable database) and the beam's energy distribution for that depth. The inclusion of the excitation function is a novelty feature of this code when comparing with the existing codes for PIGE depth profiling, which instead only use narrow resonances of the excitation function. This feature allows a simulation of a more realistic profile for the cases where more than one resonance significantly contributes to the gamma-ray yield.
Experimental results have been obtained from known samples and compared with ERYAProfling calculations, in order to validate its performance.

[1] MATEUS, R., JESUS, A.P. & RIBEIRO J.P. – A code for quantitative analysis of light elements in thick samples by PIGE. Nuclear Instruments and Methods in Physics Research B. ISSN 0168-583X, Vol. 229 (2005) p. 302–308