Quantum statistical properties of free-electron laser with ion-channel guiding

Abstract

The operation of the quantum free-electron lasers (QFELs) with a helical wiggler and in the presence of ion-channel guiding is considered. The quantum Hamiltonian of single particle has been derived in the Bambini-Renieri (BR) frame. Time dependent wave function and three constants of motion are obtained. The Raman-Nath equation (RNE) and its approximation solution have been calculated, and then the resulted solution has been employed to obtain the quantum gain, photon statistics parameter and squeezing parameter. A quantum approach has been used to get quantum statistical properties of the FEL and the photon gain formula for the small signal gain limit. It is found that the ion-channel guiding decreases the squeezing. Also, the conditions for positive (bunching) and negative (antibunching) gain have been studied numerically.

Focusing peculiarities of ion-channel guiding on a relativistic electron beam in a free-electron laser with a three-dimensional wiggler

“…Let us calculate the repulsive force among the electrons in the beam. As was often adopted in the previous papers [8][9][10][11][12][13][14][15][16][17][18], the electric field generated by the electron beam itself can be approximately regarded as what a charged rigid body does, and can be expressed, in accordance with Gaussian law, as…”

“…This electric force drives the electron moving outward in the radial direction. Meanwhile, the electron beam drifting in the longitudinal direction can be approximately treated as a direct current, which generates a magnetic field [8][9][10][11][12][13][14][15][16][17][18] Here the electron beam with a current of 300 A, an energy of 750 keV, and a radius of 0.25 cm is injected into a 3D wiggler, and propagates through a 2 m-long stainless-steel waveguide with a radius of 0.51 cm, where the bifilar helical wiggler field has a period of 3.18 cm and is slowly increased over the initial six periods up to an amplitude of 630 G.…”

“…To date, a lot of papers have been devoted to the investigation of ion-channel guiding FELs. For example, Whittum et al [8] investigated ionhose instability; Jha et al [9,10] derived the dispersion relation and harmonic generation; Esmaeilzadeh et al [11] discussed the gain equation; Raghavi et al [12] simulated the saturation mechanism; Rouhani et al [13] proposed efficiency enhancement by tapering the wiggler parameter; Saviz et al [14] suggested the use of two electron-beam streams; Mehdian et al [15] analyzed the quantum property of an ion-channel guiding FEL; Esmaeilzadeh et al [16] studied chaos of the electron motion; and Bahman et al [17] simulated the efficiency enhancement by tapering the ion-channel density.…”

Power enhancement via an ion-channel in a Raman free-electron laser

“…Compared to other plasmaloaded radio frequency devices, where external magnets are used, the advantage of ion-channel guiding, instead of the guide magnetic field, is that it cuts off the facility manufacture and operation expenses. Since the proof-of-principle experiments of the so-called ion-channel guiding FELs were made [26,27], a lot of papers have been devoted to this aspect, discussing the ion-hose instability, harmonic generation, satur ation mechanism, two-beam radiation, focusing peculiarity, electron's equilibrium orbits, motion chaos, beam temper ature effect, etc [28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

Kinetic description of a wiggler-pumped ion-channel free-electron laser by applying the Einstein coefficient technique

“…Experimental results of FEL with the ion-channel guiding have been reported by Ozaki et al (1992) and Yu et al (1992). The small signal gain for FEL with the ion-channel guiding has been studied in the context of quantum regime by solving the Raman-Nath equation (Mehdian et al 2012). Mishra described the kinetic of a low gain FEL by using the Einstein coefficient method in the helical wiggler and the axial magnetic field (Mishra 2005).…”