4,863 research outputs found
Dependence of effective spectrum width of synchrotron radiation on particle energy
For an exact quantitative description of spectral properties in the theory of
synchrotron radiation, the concept of effective spectral width is introduced.
In the classical theory, numeric calculations of effective spectral width
(using an effective width not exceeding 100 harmonics) for polarization
components of synchrotron radiation are carried out. The dependence of the
effective spectral width and initial harmonic on the energy of a radiating
particle is established
Effective spectrum width of the synchrotron radiation
For an exact quantitative description of spectral properties of synchrotron
radiation (SR), the concept of effective width of the spectrum is introduced.
In the most interesting case, which corresponds to the ultrarelativistic limit
of SR, the effective width of the spectrum is calculated for the polarization
components, and new physically important quantitative information on the
structure of spectral distributions is obtained. For the first time, the
spectral distribution for the circular polarization component of the SR for the
upper half-space is obtained within classical theory
Self-dual Yang-Mills fields in pseudoeuclidean spaces
The self-duality Yang-Mills equations in pseudoeuclidean spaces of dimensions
are investigated. New classes of solutions of the equations are
found. Extended solutions to the D=10, N=1 supergravity and super Yang-Mills
equations are constructed from these solutions.Comment: 9 pages, LaTeX, no figure
Numerical model of Electron Cyclotron Resonance Ion Source
Important features of Electron Cyclotron Resonance Ion Source (ECRIS)
operation are accurately reproduced with a numerical code. The code uses the
particle-in-cell technique to model a dynamics of ions in ECRIS plasma. It is
shown that gas dynamical ion confinement mechanism is sufficient to provide the
ion production rates in ECRIS close to the experimentally observed values.
Extracted ion currents are calculated and compared to the experiment for few
sources. Changes in the extracted ion currents are obtained with varying the
gas flow into the source chamber and the microwave power. Empirical scaling
laws for ECRIS design are studied and the underlying physical effects are
discussed.Comment: 24 pages, 41 figure
Numerical simulations of gas mixing effect in Electron Cyclotron Resonance Ion Sources
The particle-in-cell MCC code NAM-ECRIS is used to simulate the ECRIS plasma
sustained in a mixture of Kr with O2, N2, Ar, Ne and He. The model assumes that
ions are electrostatically confined in ECR zone by a dip in the plasma
potential. Gain in the extracted krypton ion currents is seen for the highest
charge states; the gain is maximized when oxygen is used as the mixing gas. A
special feature of oxygen is that most of singly charged oxygen ions are
produced after dissociative ionization of oxygen molecules with the large
kinetic energy release of around 5 eV per ion. Increased loss rate of energetic
lowly charged ions of the mixing element requires building up of the retarding
potential barrier close to ECR surface to equilibrate electron and ion losses
out of the plasma. In the mixed plasmas, the barrier value is large (~1 V)
compared to the pure Kr plasma (~0.01 V), with the longer confinement times of
krypton ions and with the much higher ion temperatures
On Optical Properties Of Ion Beams Extracted From Electron Cyclotron Resonance Ion Source
Ion extraction from DECRIS-PM source is simulated by using initial
distributions of ions at the extraction aperture obtained with NAM-ECRIS code.
Three-dimensional calculations of plasma emissive surface are done and ions are
traced in the extraction region. The ion beam profiles show strong aberrations
due to shape of plasma meniscus; hollow beam features are reproduced, as well
as changes in profiles for different focusing conditions
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