SU610459A1

SU610459A1 - Charge particle accelerator

Info

Publication number: SU610459A1
Application number: SU772461509A
Authority: SU
Inventors: Ю.П. Вахрушин; О.А. Гусев; В.С. Кузнецов
Original assignee: Предприятие П/Я А-7904
Priority date: 1977-03-28
Filing date: 1977-03-28
Publication date: 1979-10-25

Description

1one

Изобретение относитс к ускорител м зар же1шых частиц и может быть использовано дл получени потоков ускоренных электронов или ионов большого сечени , ишроко используемых в насто щее врем в радиационной технологии.The invention relates to accelerators for the charge of the same particles and can be used to obtain streams of accelerated electrons or ions of large cross section, which are currently used in radiation technology.

Известны ускорители зар женных частиц с устройством вывода пучка в рабочую область, имеющие на выходе дл увеличени поперечных размеров пучка либо ВЧ-развертывающие электромагнитные устройства 1у2, либо посто нные магниты 3. Наибольшее распространение получили ВЧ-развертывающие устройства.Accelerators of charged particles with a beam output device in the working area are known, which have either high-frequency electromagnetic devices 1 2 or permanent magnets 3 to increase the transverse dimensions of the beam. High-frequency devices are widely used.

В последнее врем в св зи с увеличением мощности пучков зар женных частиц дл вывода- этих пучков примен ют фольговые устройства с решетками, обеспешвающими механическую прочность фольги 4.Recently, in connection with an increase in the power of charged particle beams, foil devices with grids, which ensure the mechanical strength of the foil, have been used for outputting these beams.

В таких устройствах вывода пучка в рабочую область имеютс большие потери его на решетке. Это ограничивает предельную мощность ускорител и снижает его КПД.In such beam extraction devices into the work area, there are large losses on the lattice. This limits the maximum power of the accelerator and reduces its efficiency.

В предлагаемом ускорителе это устранено выполнением магнитной системы прот женной от выхода до источника зар женных частиц, охватывающей эмиттер, который снабжен маской, повтор ющей в уменьшенном масштабе конфигурацию решетки выходного окна.In the proposed accelerator, this is eliminated by making the magnetic system extending from the exit to the source of charged particles, covering the emitter, which is provided with a mask that repeats on a reduced scale the configuration of the exit window grating.

Принципиальна схема предлагаемого ускорител приведена на фиг. 1. Принвдп действи устройства по сн етс фиг. 2, 3. На фиг. 2, а дано распределение продольной составл ющей магнитного пол вдоль ускорител ; на фиг. 2,6 - траектории зар же1шых частиц в плоскости, прО ход щей через продольную ось ускорител ; на фиг. 3 - траектории зар женных частиц в плоскости, перпендикул рной продольной оси ускорител .The schematic diagram of the proposed accelerator is shown in FIG. 1. The device operation is explained in FIG. 2, 3. In FIG. 2, and the distribution of the longitudinal component of the magnetic field along the accelerator is given; in fig. 2.6 — trajectories of the charge of the same particles in the plane passing through the longitudinal axis of the accelerator; in fig. 3 — trajectories of charged particles in a plane perpendicular to the longitudinal axis of the accelerator.

Claims

The accelerator contains a source of charged particles 1, the emitter 2 of which is provided with a mask 3, providing a multipath structure of the emitted beam, an accelerating system 4, transporting channel 5, an output device 6 with a grating 7 repeating on an enlarged scale the cathode mask configuration, and a magnetic system 8 , ensuring the conservation of the multibeam structure of the beam in the accelerating system, and a similar increase in a given scale of the beam cross section at the output of the accelerator while maintaining its multipath structure. If there is a sufficiently strong magnetic field at the location of the emitter, the particles move, rotating around the magnetic field lines so that their mutual spatial arrangement does not change. At the output of the accelerator, the magnetic field lines of force diverge, thereby causing an increase in the transverse dimensions of the beam. In the region where there is no magnetic field, the charged particles move in a straight line, at the angles that they acquired at the accelerator output. With a sufficiently small initial energy spread of particles and with a linear dependence of the radial component of the magnetic field induction on the radial coordinate, these angles depend linearly on the radial position of the particle, which ensures the preservation of a similar image of the cathode at almost any distance from the accelerator. The scale of the magnification of the cathode image and the angles of the charged particles at the output of the accelerator are determined mainly by the magnitude of the magnetic field in the region of the emitter of charged particles and the nature of the decay of the magnetic field at the accelerator output. The angle of rotation of the image of the cathode can be adjusted by an additional magnetic coil located in the accelerating tract. The magnetic field created by this coil affects only the angle of rotation of the image of the emitter, without affecting the magnification of the image of the emitter. By adjusting the distribution of the magnetic field and the angle of rotation of the cathode image, it is possible to achieve an exact correspondence of the emitter image to the foil configuration between the grating elements of the output device, so that the beam loss on the foil supporting the foil will be minimal (theoretically, the loss can be reduced to zero). Invention A charged particle accelerator comprising a source of charged particles, an accelerating system, an output device with a magnetic beam expansion system, and an exit foil window with a grid, characterized in that, in order to reduce beam losses in the output window, the magnetic system is extended from the output to the source of charged particles, covering the emitter, which is provided with a mask that repeats on a reduced scale the configuration of the exit window grating. Sources of information taken into account in the examination 1. German Patent N 1204342, cl. 21 d. 21/01, published 1966.

2. US patent N 3469139, cl. 313-74, publ. 1969.

3. US patent N 3013154, cl. 250-4L5., Published. 1961.

4. Patent of Sweden No. 309634, cl. 21 D 13/29, publ. 1969.