Download of SIMNRA 6.06 was on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. This program was originally produced by Max-Planck-Institut fuer Plasmaphysik.
The program lies within Education Tools, more precisely Science Tools. The following versions: 6.0 and 5.0 are the most frequently downloaded ones by the program users.
We cannot guarantee that the program is safe to download as it will be downloaded from the developer's website. Before launching the program, check it with any free antivirus software. SIMNRA works fine with 32-bit versions of Windows XP/7/8/10/11. The program's installer is commonly called Simnra.exe.
From the developer:
SIMNRA is a Microsoft Windows program for the simulation of backscattering spectra for ion beam analysis with MeV ions. SIMNRA is mainly intended for the simulation of non-Rutherford backscattering, nuclear reactions and elastic recoil detection analysis (ERDA). More than 300 different non-Rutherford and nuclear reactions cross-sections for incident protons, deuterons, 3He, 4He and Li-ions are included.
You may want to check out more software, such as EarthBrowser, Solmetric SunEye or CAP 540, which might be related to SIMNRA.