Automation of variable low energy positron beam experiments using LabVIEW based program

Abstract

Implementation of a state of the art data acquisition and analysis program for variable low energy positron beam using LabVIEW based automation software is described. The program does the following functions: (a) controlling the remote programmable high voltage–power supply to bias the sample negatively (i.e., to vary the positron beam energy), (b) control of Windows based PCI MCA card, (c) calculating the S, W, R and ortho-positronium self-annihilation fraction (fPs) parameters, errors, and other relevant parameters, (d) saving the raw spectra, results and log data file and (e) dynamic display of raw spectrum and S, W, fPs versus energy for easy visualization of progress of the experiment. The USB based interfacing standard of this design provides easy connectivity to the personal computers.