Linear particle accelerator for charged particles

Abstract

The invention relates to an accelerator for charged particles, which consists of an accelerator tube (B) and an alternating voltage source (AC), which is designed such that the accelerator tube contains two alternating rows of electrodes (En.a) and (En.b), which are connected via connecting lines (La) and (Lb) to the opposite poles (Pa) and (Pb) of the alternating voltage source (AC). Charged particles are accelerated via the source (S) along the acceleration line (I) in such a way that a forward-directed electric field (E) resulting from the alternating voltage (U) always accelerates the particles between the two electrode rings. The electrodes are spaced apart by a distance L(π / 2), which the charged particles require to traverse during half a period (π / 2) of the alternating voltage.When passing through an electrode ring, the electrical voltage of the alternating field (uo) is zero, and the particles are moved into the next voltage field by their own speed. The electric field again reaches the maximum acceleration (am) in the center of both electrodes at the following quarter period t(π / 4) due to the maximum voltages (U+) and (U-), and then returns to zero upon reaching the next electrode. The electrodes can be simplified as a ring (R) with an inner tip (Y) so that the electric field (E) is effectively amplified along the acceleration line (I). The particle source (S) only feeds particles into the accelerator at half the period when the particle charge matches the electric field. This application significantly shortens accelerators, as drift tubes are not required as neutral regions.In addition, a forward-directed electric field is always formed, which causes the particles to be accelerated forward. This application can be used for electrons and positively charged particles.

Description

The invention relates to a charged particle accelerator consisting of an accelerator tube (B) and an AC voltage source (AC) designed such that the accelerator tube contains two alternating electrode rows (En.a) and (En.b) which are connected via the connecting lines (La) and (Lb) to the opposite poles (Pa) and (Pb) of the AC voltage source (AC).Charged particles are thereby accelerated via the source (S) along the acceleration line (I) in such a way that a forwardly directed electric field (E) as a result of the alternating voltage (U) accelerates the particles between the two electrode rings. The electrodes have the distance I(π / 2) required by the charged particles for this distance during a half period (π / 2) of the alternating voltage.When traversing an electrode ring, the electric voltage of the alternating field (u o) is zero and the acceleration zero (a0) is zero and reaches the maximum (a m) of the acceleration by the voltages (U+) and (U-) in the following quarter period I(π / 4) in order to be again zero when reaching the subsequent electrode.The electrodes can be simplified in design as a ring (R) with an inner tip (Y) in order to effectively boost the electric field (E) along the acceleration line (I).The application makes it possible to greatly shorten accelerators since an electric field which is always directed forwards is formed and the particles are constantly accelerated forwards (a).The application can be used for electrons and positively charged particles.STATEParticle accelerators accelerate charged particles to high speeds. The invention sought is concerned with linear particle accelerators, also called LINAC, which accelerate charged particles such as electrons, positrons or ions in a straight line. The first Reieute accelerators consist of linearly arranged drift tubes which have been alternately connected to the poles of a high voltage source. The particles are accelerated in the gap between the tubes and then pass passively through the shielded drift tube to the next gap while the alternating field rotates. The longer drift tubes take up the predominant part of the accelerator.The length of the neutral drift tube is needed because otherwise the particles would be decelerated from the negative vibration. More modern structures use, according to Alvarez, a standing electromagnetic wave in a tube which also protects the accelerated particles in the following half wave from the reverse temporary field by neutral drift tubes.TASKThe invention is intended to make it possible to build a linear accelerator without drift tubes, with acceleration directed continuously forwards along the acceleration line. Linear accelerators are thereby shortened.SOLUTIONThe structure is explained with reference to the figures:(FIG. 1 ): The invention relates to an accelerator for charged particles, which consists of an accelerator tube (B) and an AC voltage source (AC), wherein the accelerator tube contains two alternating electrode rows (En.a) and (En.b) which are connected via the connecting lines (La) and (Lb) to the opposite-pole poles (Pa) and (Pb) of the AC voltage source (AC).Charged particles are thereby accelerated via the source (S) along the acceleration line (I) in such a way that a forwardly directed electric field (E) as a result of the alternating voltage (U) accelerates the particles between the two electrode rings. The electrodes have the distance L(π / 2) required by the charged particles for this distance during a half period t(π / 2) of the alternating voltage.When traversing an electrode ring, the electric voltage of the alternating field (u0) is zero and the particle is moved into the next region by its own speed. There, the electric field (E) builds up and accelerates the particle in the direction of the following electrode. At this time, it reaches the maximum of the acceleration (a m) approximately at the middle of the distance when the voltages (U+) and (U-) are maximum. The alternating voltage then falls, still with a forward acceleration, in order to be zero again when the follower electrode is reached.The electrodes can be designed in a simplified manner as a ring (R) with an inner tip (Y) in order that the electric field (E) propagates effectively in an amplified manner along the acceleration line (I).The particle source provides particles only at a suitable half period depending on the charge impact. As a result, only particles are accelerated forward.The particle movement is explained on the basis of the following phases of images:(FIG. 2 ): At the time t=0, a charged particle traverses the first electrode ring (E0.a) at an initial velocity v0, which ring has no voltage (U 0) with respect to the next electrode (E0.b) and thus no electric field yet exists. The particle is moved by its own speed into the intermediate region of the two electrode rings (E0.a and E0.b).(FIG. 3 ): The electric field between the two electrodes is established. As a result, the charged particle is accelerated to the next electrode (E0.b). At the time t=π / 4, the maximum differential voltage (U max) is applied to the eletrods, as a result of which a strong electric field (E max) has formed and the maximum acceleration (a max) accelerates the particles further. After the peak, the electric field (E) is again reduced when the following electrode is reached. Until then, the charged particle is still accelerated forward.(FIG. 4 ): At the time t=π / 2, the particle reaches the second electrode (E0.b), wherein the field voltage (U min) has dropped to zero and thus no longer acts an electric field on the charged particle. The particle traverses the electrode ring by its own velocity v1 and moves into the intermediate region to the following electrode (E1.a)(FIG. 5 ): On the path at the time t=π3 / 4, a forward-directed electric field (E2 max) is again built up, which now accelerates the charged particle further to a higher speed by the inversely directed voltage (U2 max) with the acceleration (a2 max) and moves it to the third electrode (E1.a).(FIG. 6 ): At the time t=π, the particle reaches the third electrode (E1.a), wherein the field voltage (U2 min) has dropped to zero and thus no longer acts an electric field on the charged particle. The particle is further advanced at the higher velocity v2.(FIG. 7 ): To traverse the first electrode, the charged particle already needs a velocity v 0. A particle can be injected by an upstream ion source or electron source (S). However, due to the alternating voltage build-up, particles are moved into the tube only for one half wave when the appropriate electric field points in the direction. It is recommended that the ion source be set at a minimum distance L g via the voltage U g which permits the ionization U i at that time. The distance can be selected such that as far as possible only particles in the voltage peak range (W) are introduced to the first electrode (E0.a).(FIG. 8 ): The electrode rings (En.a-En.b) are alternately connected to an AC voltage source (AC), which should have a high voltage (HV) and high frequency (HF). The electrode rings should be finely adjusted at a distance over the position (p1) and adjusted over the delay time of the voltage with a length regulation (s1) in the signal position over time.(FIG. 9 ): Via the insulation (I), the connecting lines can be improved against signal faults, emissions and high-voltage short circuits. The interior of the accelerator can likewise be improved with an inner insulation (J) against undesired AC voltage effects.(FIG. 10 ): Upon further optimization, the shape of the electrodes can be configured by resonance passages (R), wherein the resonance vibration (F) between the electrodes must be tuned to the phase velocity of the particles.In addition, the density of the electric field can be improved by shaping the electrodes. Thus, an inner tip (Y) can align the electric field (E) to the center of the line of motion. In addition, with an adjusted shaping of the electrode rings (En.a and En.b), it can be achieved that when the particles of the next electrode are reached, the particle does not fly towards the electrode, but just continues to fly out, because the total electric field is then zero.Application:The accelerator can form compact particle accelerators with its shorter construction.List of Drawings:The drawings show the following representations: FIG. 1 : summary and overview FIG. 2 : Particle acceleration phase 0 t=0 FIG. 3 : Particle acceleration phase 1 t=π / 4 FIG. 4 : Particle acceleration phase 2 t=π / 2 FIG. 5 : Particle acceleration phase 3 t=π3 / 4 FIG. 6 : Particle acceleration phase 4 t=π FIG. 7 : Ion source FIG. 8 : Adjustable connections FIG. 9 : insulation FIG. 10 : Resonance structureName list:List of the designations in the drawings B: accelerator tube E0.a: first electrode ring E0.b: second electrode ring E1.a: third electrode ring E1.b: fourth electrode ring En.a: row of identical electrode rings a En.b: row of identical electrode rings b E: electric field R: ring-shaped electrode body Y: electrode tip S: particle source with charged particles U g gate voltage: particle source U i ionization voltage La: connection row a: Lb: connection row b: AC: alternating voltage source Pa: pole a Pb: pole b at the acceleration maximum a0: acceleration minimum N: repetition of the electrode pairs p1: displacement in the acceleration direction s1: displacement the connection line I insulation of the line J insulation of the accelerator tube Q resonance passage F resonance path

Claims

Linear particle accelerator for charged particles, consisting of an accelerator tube (B) and an AC voltage source (AC), wherein electrode rings (En.a) and (En.b) are alternately connected to the AC voltage source, characterized in that the distance of the electrode rings (En.a) and (En.b) corresponds approximately to the distance L(π / 2) required by a charged particle for a half period t≈π / 2 of the AC voltage for crossing the distance of two adjacent electrode rings.Linear particle accelerator according to claim 1da characterised in that the charged particles experience only forwards accelerations (a) through the temporal electric field (E) along the acceleration line (I).Linear particle accelerator according to one of the preceding claims, characterized in that no neutral drift tubes are incorporated along the acceleration line (I)Linear particle accelerator according to one of the preceding claims, characterized in that the electrode rings can be shaped in such a way that sharp regions (Y) lead to the centre of the electric field (E).Linear particle accelerator according to one of the preceding claims, characterized in that a particle source (S) can be set via the distance (I g) in such a way that the charged particles reach the first electrode ring (E0.a) at the zero point t=0.Linear particle accelerator according to one of the preceding claims, characterized in that the particle source can be adjusted such that only particles in the range of a peak voltage (U g) are transmitted to the first electrode (E0.a).Linear particle accelerator according to one of the preceding claims, characterized in that the electrode rings (En) can be adjusted at the distance (p1)Linear particle accelerator according to one of the preceding claims, characterized in that the electrode rings (En) can be adjusted in the signal transit time (s1)Linear particle accelerator according to one of the preceding claims, characterized in that the connecting lines with the insulations (I) and the inner region (J) can be shielded and electrically insulated.Linear particle accelerator according to one of the preceding claims, characterized in that the electrode rings are constructed by tuned resonant passages (Q) which are determined by the resonant section (F).

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