  Transverse and longitudinal dielectric permittivity elements are derived for
radio frequency waves in a laboratory dipole magnetic field plasma (LDMFP)
accounting for the finite ring current radius. The main feature of LDMFP is the
fact that, in contrast to planetary magnetospheric plasmas, the untrapped
(circulating) particles can exist/circulate (together with the trapped
particles) along the equilibrium magnetic field lines. To estimate the wave
power absorbed in LDMFP the perturbed electric field and current density
components are decomposed in a Fourier series over the poloidal angle. The wave
absorption is expressed by the summation of contributions of all harmonics of
the perturbed electric field and both the diagonal and non-diagonal dielectric
permittivity elements. In this paper, we analyze numerically the separate
contributions of the trapped and untrapped electrons to the imaginary part of
the longitudinal permittivity elements in LDMFP with an equilibrium
(Maxwellian) distribution functions of plasma particles in velocity space. This
information is necessary to estimate the collisionless wave dissipation by
electron Landau damping. The computations are carried out in a wide range of
the wave frequencies.
