Equivalent micro-focus target

Abstract

The invention provides an equivalent micro-focus target. After the accelerator accelerates the deuterium or deuterium-tritium mixed ion beam to the rated energy, the device uses a quadrupole lens to separate the beam spot of the large-diameter section into a beam parallel to the target surface. In the vertical direction, it is focused to the required micro-focal spot size, and defocused to a certain length in its vertical direction to form a fan-shaped ion beam. The fan-shaped ion beam bombards the moving target and produces an outgoing neutron beam equivalent to that of a microfocal spot neutron source in the spreading direction parallel to the target surface. Because the beam spot with large diameter section is expanded into a fan-shaped ion beam, the peak density of thermal power deposited on the target surface is greatly reduced, the average thermal power density is also greatly reduced, and the temperature rise of the target surface is greatly reduced accordingly. It is also possible to further increase the total power of the ion beam, thereby increasing the neutron yield, so as to reduce the equivalent spot size and increase the neutron yield at the same time. It is suitable for applications in high-yield accelerator neutron sources that require directional and point source characteristics.

Description

technical field [0001] The invention belongs to the field of nuclear technology and application, and in particular relates to an equivalent micro-focus target. Background technique [0002] The neutron generator with linear acceleration structure is a relatively mature technology, and there are many products. How to increase the neutron yield of this type of neutron generator, prolong the service life of the target, reduce the size of the focal spot, and improve the imaging quality, is an urgent problem to be solved. [0003] There are currently three ways to improve the ability of the target to withstand the bombardment power of the ion beam: one is to use a swinging target to make the target surface mechanically swing. The advantage of this method is that the ion beam is no longer on the target surface without increasing the beam spot size. Only bombard a point, but a surface, the average power is greatly reduced, the ion beam current can be increased, and the characteris...

AI Technical Summary

Problems solved by technology

[0003] There are currently three ways to improve the ability of the target to withstand the bombardment power of the ion beam: one is to use a swinging target to make the target surface mechanically swing. The advantage of this method is that the ion beam is no longer on the target surface without increasing the beam spot size. Only bombard a point, but a surface, the average power is greatly reduced, the ion beam current can be increased, and the characteristics of the point source remain unchanged; the disadvantage is that the speed of mechanical swing is not fast enough, the length of expansion is limited, the volume is large, and at the same time There is a pause at the edge of the rotation, and the transient temperature rise is relatively high. The deposition power density of a purely swinging target can be increased several times, and the increase is limited.

The second is "Rotating Target Intensive Neutron Source and Its Application" (Journal "Modern Physics Knowledge", No. 05, 1996) discloses a method of increasing the target area by using a rotating target. The advantage of this method is that it can be used without Under the condition of increasing the beam spot size, through the high-speed rotation of the target surface, the instantaneous temperature rise and the average temperature rise are greatly reduced, thereby greatly improving the ability of the target to withstand the deposition power, thereby increasing the neutron yield and flux. The disadvantage is that the structure is complex, the volume is huge, and the rotation speed is extremely fast (1000-5000 rpm), it is very difficult to further increase the rotation speed, the reliability is poor, and the cost is high; the third is CN201010238639. A small neutron source with a window gas target. The advantage of this method is that there is no fixed target, high output, and long target life. The disadvantage of this method is that the technology is extremely difficult, the vacuum system is bulky, high energy consumption, and high cost

[0004] At present, there is no micro-focus target that is economical, simple in structure, and has directivity and point source characteristics.

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