Spectra of coherent Smith-Purcell radiation observed from short electron bunches: numerical and experimental studies by Bakkali Taheri, F, Konoplev, I, Doucas, G, Reichold, A, Smith, R, Bartolini, R, Delerue, N, Andrews, H, Fuster-Martínez, N, Clarke, C, Bharadwaj, V, Stoltz, P