; Karouby, J.] McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada
; [Brandenberger, R.] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; [Firouzjahi, H.] Inst Res Fundamental Sci IPM, Sch Phys, Tehran, Iran
; [Khosravi, S.] Inst Res Fundamental Sci IPM, Sch Astron, Tehran, Iran
; [Khosravi, S.] Tarbiat Moallem Univ, Dept Phys, Fac Sci, Tehran, Iran
The formalism for computing the gravitational power radiation from excitations on cosmic strings forming a junction is presented and applied to the simple case of co-planar strings at a junction when the excitations are generated along one string leg. The effects of polarization of the excitations and of the back-reaction of the gravitational radiation on the small scale structure of the strings are studied.