9 research outputs found
Radiation from a charge circulating inside a waveguide with dielectric filling
The emitted power of the radiation from a charged particle moving uniformly
on a circle inside a cylindrical waveguide is considered. The expressions for
the energy flux of the radiation passing through the waveguide cross-section
are derived for both TE and TM waves. The results of the numerical evaluation
are presented for the number of emitted quanta depending on the waveguide
radius, the radius of the charge rotation orbit and dielectric permittivity of
the filling medium. These results are compared with the corresponding
quantities for the synchrotron radiation in a homogeneous medium.Comment: 10 pages, Latex, four EPS figure
Synchrotron radiation from a charge moving along a helical orbit inside a dielectric cylinder
The radiation emitted by a charged particle moving along a helical orbit
inside a dielectric cylinder immersed into a homogeneous medium is
investigated. Expressions are derived for the electromagnetic potentials,
electric and magnetic fields, and for the spectral-angular distribution of
radiation in the exterior medium. It is shown that under the Cherenkov
condition for dielectric permittivity of the cylinder and the velocity of the
particle image on the cylinder surface, strong narrow peaks are present in the
angular distribution for the number of radiated quanta. At these peaks the
radiated energy exceeds the corresponding quantity for a homogeneous medium by
some orders of magnitude. The results of numerical calculations for the angular
distribution of radiated quanta are presented and they are compared with the
corresponding quantities for radiation in a homogeneous medium. The special
case of relativistic charged particle motion along the direction of the
cylinder axis with non-relativistic transverse velocity (helical undulator) is
considered in detail. Various regimes for the undulator parameter are
discussed. It is shown that the presence of the cylinder can increase
essentially the radiation intensity.Comment: 18 pages, 8 EPS figure
Electromagnetic field and radiation for a charge moving along a helical trajectory inside a waveguide with dielectric filling
We investigate the electromagnetic field generated by a point charge moving
along a helical trajectory inside a circular waveguide with conducting walls
filled by homogeneous dielectric. The parts corresponding to the radiation
field are separated and the formulae for the radiation intensity are derived
for both TE and TM waves. It is shown that the main part of the radiated quanta
is emitted in the form of the TE waves. Various limiting cases are considered.
The results of the numerical calculations show that the insertion of the
waveguide provides an additional mechanism for tuning the characteristics of
the emitted radiation by choosing the parameters of the waveguide and filling
medium.Comment: 17 pages, 9 figures, discussion, graphs, and references adde
A convolution integral representation of the thermal Sunyaev-Zel'dovich effect
Analytical expressions for the non-relativistic and relativistic
Sunyaev-Zel'dovich effect (SZE) are derived by means of suitable convolution
integrals. The establishment of these expressions is based on the fact that the
SZE disturbed spectrum, at high frequencies, possesses the form of a Laplace
transform of the single line distortion profile (structure factor).
Implications of this description of the SZE related to light scattering in
optically thin plasmas are discussed.Comment: 11 pages, 2 figures. Accepted for publication in J. Phys.
A Study of B0 - anti-B0 mixing using semileptonic decays of B hadrons produced from Z0
The B0-BÌ0 mixing was studied by using about 250000 hadronic decays of the Z0,_collected with the DELPHI detector at LEP. With 1665 dilepton events, the probability for a b quark to become a bÌ before decaying was found to be Ï = 0.121-0.040 0.044 ± 0.017. The semileptonic branching ratio of the b was measured from the dilepton and single lepton events and found to be Br(b â l) = (10.0 ± 0.7 ± 0.7)%.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe