  Using a periodic electron beam bunch train to resonantly excite plasma
wakefields in the quasi-nonlinear (QNL) regime has distinct advantages over
employing a single, higher charge bunch. Resonant excitation in the QNL regime
can produce plasma electron blowout using very low emittance beams with a small
charge per pulse: the local density perturbation is extremely nonlinear,
achieving total rarefaction, yet the resonant response of the plasma electrons
at the plasma frequency is preserved. Such a pulse train, with inter-bunch
spacing equal to the plasma period, can be produced via inverse free-electron
laser bunching. To achieve resonance with a laser wavelength of a few microns,
a high plasma density is used, with the attendant possibility of obtaining
extremely large wakefield amplitude, near 1 TV/m for FACET-II parameters. In
this article, we use particle-in-cell simulations to study the plasma response,
the beam modulation evolution, and the instabilities encountered, that arise
when using a bunching scheme to resonantly excite waves in a dense plasma.
