Comparison of reflector concepts for a 250 GHz CARM cavityS. Ceccuzzi, G. Dattoli, E. Di Palma, A. Doria, G.P. Gallerano, G.L. Ravera, I. Spassovsky, A.A. Tuccillo and ENEA CARM TeamEPJ Web Conf., 149 (2017) 04009DOI: https://doi.org/10.1051/epjconf/201714904009