Numerical study of the dispersion characteristics of a semi-circularly corrugated slow wave structure Md. Ghulam Saber, Rakibul Hasan Sagor and Md. Ruhul Amin Eur. Phys. J. D, 69 2 (2015) 38 Published online: 05 February 2015 DOI: 10.1140/epjd/e2014-50798-5