Storage ring free electron laser dynamics in presence of an auxiliary harmonic radio frequency cavityC. A. Thomas, J. I.M. Botman, C. Bruni, G. Orlandi, G. de Ninno, D. Garzella and M. E. CouprieEur. Phys. J. D, 32 1 (2005) 83-93DOI: https://doi.org/10.1140/epjd/e2004-00200-6