Material selection considerations for coaxial, ferrimagnetic-based nonlinear transmission lines J. Appl. Phys. 113, 064904 (2013) Graphene on boron nitride microwave transistors driven by graphene nanoribbon back-gates Appl. Phys. Lett. 102, 033505 (2013) Millimeter scale electrostatic mirror with sub-wavelength holes for terahertz wave scanning Appl. Phys. Lett. 102, 031111 (2013) Leaky and bound modes in terahertz metasurfaces made of transmission-line metamaterials J. Appl. Phys. 113, 033105 (2013) Additional information on Rev. Sci. Instrum. The linac driven coherent THz radiation source at the SPARC-LAB test facility is able to deliver broadband THz pulses with femtosecond shaping. In addition, high peak power, narrow spectral bandwidth THz radiation can be also generated, taking advantage of advanced electron beam manipulation techniques, able to generate an adjustable train of electron bunches with a sub-picosecond length and with sub-picosecond spacing. The paper reports on the manipulation, characterization, and transport of the electron beam in the bending line transporting the beam down to the THz station, where different coherent transition radiation spectra have been measured and studied with the aim to optimize the THz radiation performances.