A dual-period bias magnetic focusing system and traveling wave tube suitable for zonal injection

Abstract

The present invention provides a dual-period biased magnetic focusing system and traveling wave tube suitable for strip electron beams. The magnetic focusing system comprises two magnetic assembly groups arranged opposite each other along a first direction; a space for accommodating a slow-wave circuit is formed between the two magnetic assembly groups; the magnetic assembly comprises a magnetic group; the magnetic group comprises a first pole shoe, a magnet, and a second pole shoe disposed within the magnet; the axis of the first pole shoe extending along the first direction deviates from the axis of the magnet extending along the first direction toward the side of the magnet disposed along the first direction; the first pole shoes of the magnetic groups arranged opposite each other in the first direction deviate in opposite directions, and the first pole shoes of the magnetic groups arranged adjacent to each other in the second direction deviate in opposite directions; the second pole shoe is exposed from the magnet toward the wall of the slow-wave circuit and is coaxial with the magnet in the first direction. This magnetic focusing system can solve the problem of existing dual-period focusing systems in which strip electron beams rotate during transmission and hit the walls of the electron beam channel, resulting in a reduced flow rate.

Claims

1. A dual-period bias magnetic focusing system suitable for strip injection, characterized in that: include: Two groups of magnetic components are arranged opposite to each other along a first direction; A space for accommodating a slow-wave circuit is formed between the two sets of magnetic components; The magnetic group assembly includes a plurality of magnetic groups arranged along the second direction; The magnetic assembly includes a first pole shoe and a magnetic steel arranged and fixedly assembled along a second direction, and a second pole shoe disposed within the magnetic steel; the first direction is perpendicular to the second direction; The axis of the first pole shoe extending in the first direction deviates from the axis of the magnetic steel extending in the first direction toward the side where the magnetic steel is arranged in the first direction; The first pole shoes of the magnetic groups arranged opposite to each other in the first direction are deviated in opposite directions, and the first pole shoes of the magnetic groups arranged adjacent to each other in the second direction are deviated in opposite directions; The second pole shoe is exposed from the magnetic steel toward the wall surface of the slow-wave circuit and is coaxially arranged with the magnetic steel in the first direction.

2. The dual-period bias magnetic focusing system suitable for strip injection according to claim 1, characterized in that: The cross sections of the magnetic steel, the first pole shoe and the second pole shoe are all rectangular.

3. The dual-period bias magnetic focusing system suitable for strip injection according to claim 1, characterized in that: The magnetic steel includes a slot body for accommodating and fixing the second pole shoe, wherein the slot body is formed by a portion of the wall of the magnetic steel facing the slow-wave circuit being recessed inward; the second pole shoe is exposed through an opening of the slot body; The wall surface of the second pole shoe facing the slow-wave circuit is in the same horizontal plane as the slot opening of the slot body.

4. The dual-period bias magnetic focusing system suitable for strip injection according to claim 1, characterized in that: The magnetic steel includes a first magnet, a second magnet and a third magnet arranged and fixed along a second direction; a slot body for accommodating and fixing the second pole shoe is formed between the second magnet and the inner side wall of the first magnet and the inner side wall of the third magnet.

5. The dual-period bias magnetic focusing system suitable for strip injection according to claim 1, characterized in that: The magnetization directions of two adjacent magnetic groups in the second direction are opposite; the magnetization directions of two magnetic groups opposite to each other in the first direction are the same.

6. The dual-period bias magnetic focusing system suitable for strip injection according to claim 1, characterized in that: The width of the magnetic steel in the third direction is x1, and the width of the second pole shoe in the third direction is w1; x1≥w1; and the third direction is perpendicular to both the first direction and the second direction.

7. The dual-period bias magnetic focusing system suitable for strip injection according to claim 6, characterized in that: The width of the first pole shoe in the third direction is w2, and the distance between the axis of the first pole shoe extending in the first direction and the axis of the magnetic steel extending in the first direction is d. x ;w2+2d x ≤x1.

8. The dual-period bias magnetic focusing system suitable for strip injection according to claim 1, characterized in that: The height of the first pole shoe in the first direction is h3, the height of the second pole shoe in the first direction is h1, and the height of the magnetic steel in the first direction is h2; h1 <min(h2,h3)。 9. A traveling wave tube, characterized in that: It comprises a slow-wave circuit and the magnetic focusing system according to any one of claims 1 to 8; the slow-wave circuit is arranged between two groups of magnetic components and extends along the second direction.

10. The traveling wave tube according to claim 9, characterized in that: The slow-wave circuit comprises a tube shell with a rectangular cross section and a slow-wave structure fixed in the tube shell; the electron injection channel of the slow-wave structure is a rectangular cross-section channel or an elliptical cross-section channel.

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