A Spoke Cavity Structure for Large Hadron Accelerator

Abstract

The invention discloses a spoke cavity structure for a large hadron accelerator. The two ends of the mandrel are respectively provided with arc-shaped convex surfaces, and each arc-shaped convex surface protrudes from the outer peripheral cylindrical surface of the spoke cavity. The mandrel is along the radial direction of the spoke cavity. through the spoke cavity. The spoke cavity structure used in this large hadron accelerator is improved on the basis of the traditional spoke cavity structure. By setting an arc-shaped convex surface on the outer circumference of the first rounded corner in the traditional spoke cavity structure, the electromagnetic field distribution near the first rounded corner can be effectively improved. At the same time, it can effectively reduce the effective secondary electron emission coefficient of the spoke cavity to an acceptable range, and avoid the influence of the mandrel itself on the electromagnetic field distribution.

Description

technical field [0001] The invention relates to the technical field of accelerators, in particular to a spoke cavity structure for a large hadron accelerator. Background technique [0002] As a superconducting high-frequency cavity, the spoke cavity is often used for the acceleration of medium-energy particles (0.4<β<0.7), where β is the ratio of the particle speed to the speed of light. Compared with the ellipsoidal cavity, the spoke cavity has the advantages of high mechanical strength and a wide range of accelerated particle speeds. Therefore, many large hadron accelerators in the world currently use the spoke cavity as the medium-energy acceleration structure for particles. However, in practical applications, the operating state of the spoke cavity is affected by the effective secondary electron emission coefficient. If its structural design is unreasonable, its working cavity pressure will be at the effective secondary electron emission coefficient ( <sey>)...

AI Technical Summary

Problems solved by technology

[0003] In the commonly used spoke cavity at present, in general, the secondary electron emission of the double acceleration gap spoke cavity mainly exists in two positions (such as figure 1 or figure 2 The first fillet 1 shown and the second fillet 2), wherein the effective secondary electron emission coefficient at the second fillet can be suppressed to an acceptable range by increasing the fillet radius (ie less than 1.4); but for the effective secondary electron emission coefficient at the first fillet, it is generally impossible to reduce the effective secondary electron emission coefficient by changing the radius of the fillet, because the mandrel 3 destroys the circumferential cavity structure, It will cause the electromagnetic field distribution at the first rounded corner to be no longer uniform, which in turn leads to the uncertainty of the secondary electron emission trajectory

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