A generalized fitting tool for analysis of two-dimensional channeling patterns

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 462; pp. 102 - 113
• Main Authors: David-Bosne, E., Wahl, U., Correia, J.G., Lima, T.A.L., Vantomme, A., Pereira, L.M.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2020
• Subjects: Blocking pattern; Emission channeling; Fitting software; Image scan; Position-sensitive detector; RBS/C; Two-dimensional channeling pattern; Blocking pattern; Position-sensitive detector; Emission channeling; RBS/C; Fitting software; Image scan; Two-dimensional channeling pattern
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2019.10.029

The acquisition of two-dimensional (2D) channeling patterns is gaining increased popularity within the ion beam community. However, with the exception of emission channeling experiments for the lattice location of radioactive impurities, quantitative analysis of such patterns is rarely found. We present a general description of the statistical data analysis methodology for 2D channeling patterns, which consists of comparing experimental data by means of a fit procedure to theoretical yield distributions. The developed software allows for chi-square or maximum likelihood-based fits, optimizing the orientation of the theoretical vs the experimental pattern, as well as the best choice of random level, and providing fractions for the contributions from several theoretical patterns related to different lattice sites. Optionally also the angular resolution can be used as a fit parameter. Use of the software is illustrated by examples of electron emission channeling from 27Mg in GaN, as well as 4He RBS channeling from Ge.