SU747394A1 - Device for phase-grouping of accelerated charged particle beam - Google Patents

Description

(54) DEVICE FOR PHASE GROUPING OF BEAM ACCELERATED CHARGED PARTICLES

The invention relates to devices for grouping accelerated charged particles in the longitudinal direction and can be used in high-frequency electronics, for example, in high-frequency power generators as well as in experimental nuclear physics. A phase grouping device is the basis of the klystron of a high frequency power amplifier. The device contains an input resonator with a longitudinal electric field and a grouping element — drift space with a rectilinear axis. The high-frequency electric field both bakes the high-speed modulation of accelerated electrons. Due to the difference in transit time, the modulation of velocity leads to the phase grouping of electrons at the end of space. A disadvantage of a klystoron type device is the inhomogeneity of the energy of a beam of charged particles introduced by the input resonator. This lowers the electron efficiency of klystrons, and when used in sodophysical experiments, degrades the resolution of the measurement results. It is also known a device for the phase grouping of accelerated charged particles used in experimental nuclear physics. The device contains a high-frequency deflector with a transverse electric field, the subsequent grouping element is a rotating magnet with a stationary field, as well as focusing lenses. installed before and after the magnet 2. The high-frequency electric field of the deflector performs a linear sweep of the beam. Particles that arrived earlier in the phase go a greater way in the grouping magnet, those that come later - a smaller way. As a result, due to the difference in transit times, there is a phase grouping of particles after the magnet. A device with a grouping magnet practically does not contribute to the grouped beam, the inconsistency of energy, if the initial beam is narrow. The disadvantage of the device with a grouping element in the form of a rotary magnet is the curvature of the optical axis of the device, which leads to the complication of layout schemes of installations using the phase grouping of charged particles.

The aim of the invention is to implement a phase grouping without introducing energy heterogeneity into a beam in a device with a rectilinear axis.

 achieving this goal in a device for phase grouping of a beam of charged particles, having a high-frequency deflector, focusing 1e 7, lenses and a grouping element, grouping the element is made containing two plane-parallel conductive fibers, astins and coils with current, ensuring the creation in the gap between plates of static electric and magnetic fields, the directions of which are perpendicular to each other. According to the design concept, the grouped element is similar to the electrostatic separator 2 used in high-energy physics, in which the deflection of particles of a certain mass by the transverse electrostatic field is compensated by the action of a stationary magnetic field, which ensures the linearity of the optical axis of the system.

The drawing shows a structural diagram of the proposed device for the phase grouping of a beam of accelerated charged particles and shows the trajectories.

A phase grouping device has a high-frequency deflector 1 with a transverse electric field, focusing lenses (for example, quadrupole magnetic doublets) 2 and a grouping element containing successive conductive plates 3 and 4 with a polarity of opposite polarity connected to them, as well as coils 5 with current, size: above and below the symmetry plane of the device. After the grouping element, a terminal block b is set (target when using phase grouping in experimental nuclear physics or an output cavity in a high-frequency power generator). Positions 7-10 designate particle trajectories.

The high-frequency deflector 1 performs a linear sweep of the beam entering it with an axial trajectory 7, After the deflector, the trajectory 8 corresponds to the particles, with the deflector at zero phase and phase 180. The extreme trajectories 9 and 10 correspond to the BeTCtByraT phases + 90 °. Trajectory 8 remains straight in the gap between plates 3 and 4. This will occur if the strength of the electrostatic field E and the magnetic field in (this field is created by coils 5 with current and is directed perpendicular to the plane of the drawing) are connected by the ratio 1 Е (V / M) -

B (T,) -i10,

AT

where e is the particle velocity in units

the speed of light in a vacuum. After lens 2, the trajectories 9 and 10 become almost parallel to the trajectory 8. In the gap between the plates of the trajectory 9 and 10 are at a distance h from the trajectory 8, on which the electrostatic potential is zero. The potential on the trajectory 9 is equal to Eh, on the trajectory 10 is equal to + E.I.If the initial kinetic energy of particles with charge e is W, then inside the grouping element for the trajectory

9 it is equal to W - eEh, and for the trajectory

10 is equal to W + eEh, and it is assumed that 0 eEh "W. Particle energy modulation

 leads to a modulation of their speed. As in the klystron, due to this effect, at the end of the drift space of length 1 (the length of the plates 3 and 4) will be

5 to have a phase grouping of particles. When the particles exit the gap between the plates, the initial value of the kinetic energy W is restored for all trajectories;

fj of the block b, a focus is created of the grouped beam of the phases, and the grouping process does not create an energy inhomogeneity.

Claims (2)

1. Lebedev N.V. Appliances and devices 55 microwave .. T. And. Electrovacuum devices UHF, M ,, Higher School, 1972. 2. Benford A, Transportation of beams of charged particles. M., Atomiedat, 1969.