RU2069026C1 - Multibeam o-type device - Google Patents

Abstract

FIELD: microwave devices. SUBSTANCE: device incorporating electrodynamic system wherein transit-time channels are arranged in several rows on concentric cylindrical surfaces has center of each transit-time channel in output section offset in azimuthal direction relative to its center in input section through distance specified by definite relationship. EFFECT: improved design. 4 dwg

Description

 The invention relates to O-type electrovacuum devices, in particular to multipath klystrons and traveling-wave lamps.

 The aim of the invention is to increase the average power output and durability by improving current flow.

 The design of the device is shown in FIG. fourteen.

вектор индукции продольного внешнего фокусирующего поля, Δ_i смещение в азимутальном направлении центра пролетного канала в выходном сечении относительно центра во входном сечении.In FIG. 1 shows the layout of the passage channels of the device, O ₁ O _{2 the} axis of the device, 1 channels of a certain i-th row, 2 axes of these channels, α _{i the} angle between the axis of the device and the axis of the channel of the i-row, 3 channels of the inner rows, 4 axes of these channels, R _{i is the} radius on which the centers of the channels of the i-th row are located,

the induction vector of the longitudinal external focusing field, Δ _{i is the} displacement in the azimuthal direction of the center of the passage channel in the output section relative to the center in the input section.

 In FIG. 2 shows a magnetic field line generated by a linear current.

, созданной током m-го канала, расположенного на расстоянии r_m от q-го парциального потока. γ_m угол между радиусом R_i и прямой mq.In FIG. 3 shows the projection of B _θ2m on the azimuthal direction of magnetic induction

created by the current of the m-th channel located at a distance r _m from the q-th partial flow. γ _{m is the} angle between the radius R _i and the straight line mq.

, т. е. векторная сумма внешнего продольного фокусирующего поля

и азимутального поля

, созданного парциальными электронными потоками. Токи, протекающие по каналам, внешним по отношению к рассматриваемому i-му, не влияют на величину азимутальной компоненты поля на радиусе R_i.In FIG. 4 shows the total magnetic induction vector

, i.e., the vector sum of the external longitudinal focusing field

and azimuth field

created by partial electron streams. The currents flowing through channels external to the ith considered do not affect the magnitude of the azimuthal field component at a radius R _i .

 The device operates as follows.

и собственного магнитного поля

силовые линии магнитного поля становятся винтовыми линиями с углом закручивания a_i.. Электроны каждого парциального потока движутся в этом поле, в среднем следуя силовым линиям. В результате оси парциальных потоков также приобретают вид винтовых линий с тем же углом закручивания, так что центр каждого потока в выходном сечении смещается в азимутальном направлении на величину Δ_i. Для снижения динамического токооседания оси парциальных каналов должны быть развернуты в пространстве на тот же угол α_i, так что центр каждого парциального канала в выходном сечении смещен в азимутальном направлении на величину Δ_i относительно его центра во входном сечении.Due to the vector addition of the external focusing magnetic field

and intrinsic magnetic field

magnetic field lines become helical lines with a twist angle a _i .. The electrons of each partial flux move in this field, on average following the field lines. As a result, the axes of the partial flows also take the form of helical lines with the same twist angle, so that the center of each stream in the output section shifts in the azimuthal direction by Δ _i . To reduce the dynamic current subsidence, the axes of the partial channels must be rotated in space by the same angle α _i , so that the center of each partial channel in the output section is shifted in the azimuthal direction by Δ _i relative to its center in the input section.

(1)
Здесь сила тока J выражена в амперах, r в метрах, B_θ в тесла, магнитная проницаемость свободного пространства μ_o= 4π•10^-7 Гн/м.The magnitude of the twist angle and linear displacement in the azimuthal direction is calculated from the following considerations. According to the Bio-Savard-Laplace law, the magnetic induction of the linear current J is directed azimuthally (Fig. 2) and at a distance r from it is equal to:

(one)
Here, the current strength J is expressed in amperes, r in meters, B _θ in Tesla, and the magnetic permeability of free space is μ _o = 4π • 10 ^-7 GN / m.

(2)
где N_j число пучков в j-м ряде.The azimuthal component of the field B _θ at the point q (Fig. 3) on the radius R _{i is} composed of the field B _θ1 created by the total current of the beams placed inside a circle of radius R _i and the field B _θ21 created by the current of the beams placed on the radius R _i . With the equality of the partial currents J _o and their uniform distribution over the circles of each series with number j <i, taking into account (1), we have:

(2)
where N _{j is the} number of beams in the jth row.

(3)
(2) и (3) получаем суммарную азимутальную компоненту поля в точке:

(4)
Из отношения B_θ и В_z вычисляется угол закручивания

(5)
и линейное смещение Δ_i центра потока в азимутальном направлении на длине канала L:

(6)
Величины L и R_i должны быть выражены в одинаковых единицах, смещение Δ_i в метрах, B_z в тесла.Induction B _{θ2 is} calculated by summing the azimuthal components of the magnetic fields generated at point q by the remaining partial currents of the ith row of channels (Fig. 3):

(3)
(2) and (3) we obtain the total azimuthal component of the field at the point:

(4)
From the ratio of B _θ and B _z , the twist angle is calculated

(5)
and a linear displacement Δ _{i of} the flow center in the azimuthal direction along the channel length L:

(6)
The values of L and R _i must be expressed in identical units, the offset Δ _i in meters, B _z in tesla.

The correction factor k _i 0.8 -2.3 is introduced into formula (6).

Its lower boundary is less than 1, because relation (1), and therefore (5) and (6) are valid for a linear current of infinite length, for a finite current length B _{θ is} smaller by a small amount (less than 10%). In addition, the twist angle should be selected taking into account destabilizing factors. The upper boundary of the coefficient k _i is determined from design considerations. In devices with many rows of channels, the rotation angles a _i in each row are different. The implementation of the offset distance Δ _i for each of the rows exactly in accordance with formula (6) without the correction coefficient k _i to the asymmetric mutual arrangement of the channels of different rows in the output section of the electrodynamic system compared to its input section.

It is desirable, in some cases, to maintain a symmetrical arrangement of the output sections, making it the same as the input ones. The spin angle of the outer row of channels will be decisive here, since it carries the greatest current. This explains the choice of the upper boundary for the correction coefficient k _i , based on the analysis of a number of real systems.

 In the case of applying a reverse focusing system containing sections of a unidirectional field and short zones of equality (changing the sign of the field), the calculation of the angle of inclination of the axis of the channel is divorced according to the above formula within each section of a homogeneous field taking into account its sign.

 The technical implementation of the proposed solution for devices whose passage channels contain interaction gaps inside the electrodynamic system, as in klystrons or traveling wave tubes on a chain of coupled resonators, can be implemented, for example, by shifting the straight channels of individual drift pipes relative to neighboring ones according to relation (6) (stepwise helix approximation). YYY1 YYY2 YYY3

Claims (1)

An O-type multi-beam microwave electric device containing a magnetic focusing system and an electrodynamic system with span channels arranged in several rows on concentric cylindrical surfaces, the axis of which coincides with the direction of a uniform focusing magnetic field, characterized in that, in order to increase the average power and durability due to improved current flow, the center of each passage channel in the output section of the electrodynamic system is shifted in the azimuthal direction relative to tionary its center in the inlet section for a distance according to the relationship Δ _i

where K _{i is the} coefficient for the i-th row, taking values from 0.8 to 2.3;
L the length of the passage channel, m;
I _{about the} current of the partial beam, A;
B _z induction of a uniform focusing magnetic field, T;
R _{i the} radius of the cylindrical surface on which the axis of the channels of the i-th row, m;
N _j , N _{i the} number of electron beams in the j-th and i-th rows, respectively.

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