Bi-harmonic free electron laser gain with variably polarizing undulator

Harmonic undulator radiations with constant magnetic field

“…Free electron lasers of short wavelength using modest electron beam energy and to increase the efficiency of FELs system design are the prime target achieved through a harmonic undulator [7][8][9][10][11][12][13][14][15]. In this paper we have presented semi-analytical results for the effect of constant magnetic field on the performance of harmonic undulator at higher harmonics.…”

Analysis of undulator radiation with an electromagnet undulator

“…This is a distinctive feature of electromagnet undulators in comparison with PPM based undulators. In the case of PPM undulators, vanadium permendur strips are used to modify the PPM undulator for higher harmonic lasing [11][12][13][14][15][16][17]. In the case of electromagnet undulators, higher harmonic lasing is arguably possible if the electron beam is shifted up and away from the axis.…”

Design and magnetic measurements of bi-harmonic undulators for free electron laser

“…Higher harmonic operation of free electron lasers has significant implications for compact, short wavelength free electron laser systems using high quality accelerators with relatively modest energy. Studies of higher harmonic FELs have been reported by several groups world wide [1][2][3][4][5][6]. An experiment of the third harmonic lasing in FEL has been reported [8].…”