Resonant Interaction Between an Active Molecular Medium and a Free Electron Laser

Abstract

The system of a relativistic electron beam and an active molecular (maser) medium in the presence of a ripple magnetic field is studied theoretically. The tunability of the free electron laser could be used to reach different lines of such a molecular medium. We use a Lorentz model to describe the molecular transitions, a hydromagnetic model for the beam, and formulate the resonance condition for the two cases where (i) the coupling occurs at a common interface, e.g., cylindrical, between the beam and the molecular medium, and (ii) the beam and the molecules fill the same volume in space.The coupling between the beam and the molecules offers possibilities of enhanced radiation and improved coherence. In the case where the free electron laser acts as a pump of the molecules stimulated radiation could in principle be obtained at a new wavelength, i.e., the coupled system acts as a frequency transformer.

Ionization Effects in a System of a Free Electron Laser and a Molecular Medium

“…(iv) Typical beam current densites for the FEL system are expected to be below threshold values for instabilities of beam drift modes and space charge stopping of beam propagation [ 5 ] .…”

Fusion and the cosmos

“…One notices that one has to impose the condition αµ/ν − 1 = 0 or (3α + Γ)/Γ = 0 in equation (14) to obtain the characteristic linear dependence of the expansion velocity V on the distance L expressed by the Hubble relation (15). As a result one obtains from the expressions (9)-(11) the remarkably simple relation (3α + Γ) = 0 (16) and from the equations (14)- (16) …”

“…To obtain a consistant and physically meaningful description by means of the equations (4)- (6) with (7)- (12), and to use the proper direction of time, related to the sign in the Hubble law (15), one has to avoid the singularity by an amount ε such that 3α + Γ = −ε (18) or…”