  The present paper reports on the recent activity of the data analysis
software development for total-reflection high-energy positron diffraction
(TRHEPD), a novel experimental technique for surface structure determination.
Experiments using TRHEPD are being conducted intensively at the Slow Positron
Facility, Institute of Materials Structure Science, High Energy Accelerator
Research Organization, revealing surface structure of interest. The data
analysis software provides a solution to the inverse problem in which the
atomic positions of a surface structure are determined from the experimental
diffraction data (rocking curve). The forward problem is solved by the
numerical solution of the partial differential equation in the quantum
scattering problem. A technical demonstration with a test problem was carried
out to confirm the software functioned as expected. Since the analysis method
has a general mathematical foundation, it is also applicable to other
experiments, such as X-ray or electron diffraction experiments.
