Focusing Of Charged Particles Research Articles

Performance and application of heavy ion nuclear microbeam facility at the Nuclear Physics Institute in Řež, Czech Republic

The Tandetron Laboratory of the Nuclear Physics Institute of the Czech Academy of Sciences is equipped with five beam lines associated with a 3 MV tandem electrostatic accelerator model 4130 MC from High Voltage Engineering Europa B.V. This accelerator is coupled with two duoplasmatron sources and a single sputter ion source and provides ions from hydrogen to gold. One of these lines is a nuclear microbeam facility, utilizing ion beams of micro- and sub-micro sizes for materials research by use of particle induced x-ray emission spectroscopy, particle induced gamma emission, Rutherford back-scattering spectroscopy, and scanning transmission ion microscopy methods as well as for ion beam writing. The major advantage of the presented microprobe is a possibility of 3D structure creation not only in polymer materials using light ions but also in other materials such as glass, ceramics, etc. by use of heavy ions. The focusing system allows focusing of charged particles with a maximum rigidity of 11 MeV amu/q2. The usual resolution in high and low current modes is 2 × 3 µm2 for a 100 pA and 0.3 × 0.5 µm2 for the 2000 ions/s of 2 MeV protons, respectively. A detailed facility description is given in the paper. The applications of focused beams of heavy ions as well as examples of light ions utilizing are also presented in the article.

Mathematical model of the reverse water post­purification at mining enterprises when using electromagnetic focusing of contaminants

This study addresses the post-purification of reverse water by the electromagnetic focusing of charged particles in contaminants of polychlorinated biphenyls at mining enterprises. We established functional dependences of the Larmor radius of focusing of contaminant ions on operating parameters of the electromagnetic post-purification system (current strength of the focusing coil, length of the focusing coil), which allowed us to justify the required current of 0.025 A in the focusing coil for the post-purification of a liquid from polychlorinated biphenyls. The developed model of the electromagnetic system for water post-purification from the ions in contaminants made it possible to select the required Larmor radius for focusing the polychlorinated biphenyls in order to remove them effectively from a flow of liquid. As a result of post-purification, the contaminants are focused along the axis of the main flow that enables their removal through an additional branch pipe. Under the effect of the orbital moment that occurs due to magnetic induction, the motion vector of contaminants changed, and they are focused in the center of the fluid flow. We established the logarithmic dependence of height of the focusing paraboloid, which decreases from 0.057 m to 0.032 m with an increase in current of the focusing coil from 0.01 A to 0.1 A. This is due to an increase in the kinetic energy, transmitted by the charged particles, and an increase in the centripetal force. Determining the height of the focusing paraboloid makes it possible to effectively place the equipment for the removal of contaminations from the flow, and purify it

A System of Two Identical and Opposite Magnets Focusing Beam Charged Particles Passing Through Them

In this work, we use two magnets placed in front of the path of charged particles to obtain the best focusing of charged particles in both the horizontal and vertical planes. We trace the path of charged particles from the extraction region at the ion source, until reach to the target were traced. The process of tracing the path of charged particles is performed using matrices Transfer Matrix (R-Matrix) and. Beam Matrix)in each region in which passing the charged particles, starting from the extraction region reaching to the target by describing the charged particle beams as phase space ellipse in both the horizontal and vertical planes. The ion beam described as phase space ellipse then study the behavior of beam at the edges of magnet with Identical and Opposite.

Space-time focusing of charged particles in radio-frequency linear electric fields

The properties of space-time focusing of nonmonoenergetic ions in linear high-frequency electric fields are studied. The degree of time focusing of ions in high-frequency fields of hyperboloidal analyzers belonging to the monopole and dipole types is estimated. The possibility of the time-of-flight mass separation of nonmonoenergetic ions in radio-frequency mass reflectors is substantiated.

Electromagnetic mirror objective with removable spherical aberration

The authors consider focusing of charged particles in the two-electrode electromagnetic mirror with rotational symmetry whose cylindrical electrodes also act as magnetic electrodes.Calculations for different ratios of magnetic and electric components of the electromagnetic field have been made. The region in variations of geometrical and electrical mirror parameters where the third-order aberration vanishes to zero has been detected.

Deflection and focusing of charged particles by cavities of general shape

Abstract The integrated transverse momentum change of a charged particle in the rf field of a cavity can be related to the change of its voltage gain due to a virtual transverse displacement of its orbit. Formulas for the particle deflection are derived, which are a generalisation of the Panofsky-Wenzel theorem to an arbitrary cavity shape and to curved orbits through the cavity. In addition, some useful formulas for the transverse and longitudinal focusing are presented.

Multiple scattering and focusing of charged particles in a magnetized iron medium

The behaviour of charged particle beams with arbitrary primary distribution in media of magnetized iron with axially symmetric and transverse homogeneous fields is considered on the base of the kinetic equation. The results are applied to a complicated system, consisting of sections of such a medium, separated by free intervals.

200. Effect of the stray field of a plane electrostatic capacitor on the focusing of charged particles: A F Malov and E P Fedoseev,Zh Tekh Fiz, 36(8), Aug 1966, 1351–1356 (in Russian)

200. Effect of the stray field of a plane electrostatic capacitor on the focusing of charged particles: A F Malov and E P Fedoseev,Zh Tekh Fiz, 36(8), Aug 1966, 1351–1356 (in Russian)

Design curves for 180 degree magnetic spectrometers.

The image shapes resulting from 180° focusing of charged particles in a homogeneous magnetic field have been computed. General curves are presented in terms of three variables for variable ρ-spectrometers (as in the case of photographic detection) and in terms of four variables for constant ρ-spectrometers (as in the case of detection with a fixed counter). The variables are source and exit-slit height, source width, angular selection, and exit-slit width. The advantages of using sources and exit-slits with a large dimension parallel to the magnetic field (i.e., height) are noted.

The Focusing of Charged Particles by a Spherical Condenser

The paths of charged particles traversing a portion of an ideal spherical condenser are worked out. The section of the condenser considered is bounded by two rays, enclosing an angle $\ensuremath{\Phi}$, from the common center of curvature, $O$, of the equipotential surfaces. It is shown that a group of particles, homogeneous in energy, leaving a point $P$ on a normal to one of these boundaries and entering the condenser along this normal as a diverging bundle, will be brought to a focus at a point $Q$ lying on the line $\mathrm{PO}$ extended, if the proper potential is applied to the condenser. This permits the whole condenser gap to be used as a focusing energy analyzer, or monochromator, of very large useful aperture. The velocity dispersion and reduced velocity dispersion are calculated for the most general case, and are found to take the same simple form as do the corresponding expressions for the limited homogeneous magnetic field spectrograph. The expressions for the reduced velocity dispersion are identical in the two cases. Compensation for edge effect is discussed. The relativistic modification of the theory required for high speed particles is discussed and results are presented which indicate that the simple theory of the electrostatic spectrograph may be inadequate even for fairly low values of $\frac{v}{c}$. It is suggested that this difficulty may be avoided by the choice of suitable instrument parameters.An analyzer is described which has a useful aperture of 0.210 steradians, a theoretical reduced dispersion of 1010, and which requires a total focusing potential of 0.315 $E$, where $E$ is the particle energy in equivalent volts. The operation of the analyzer in focusing electrons accelerated by a field designed to furnish an equivalent point source is described.