He ion irradiation effects on multiwalled carbon nanotubes structureEmad M. Elsehly, Nikolay G. Chechenin, Alexey V. Makunin, Andrey A. Shemukhin and Hussien A. MotawehEur. Phys. J. D, 71 4 (2017) 79DOI: https://doi.org/10.1140/epjd/e2017-70658-0