RU2214018C2 - X-ray radiator - Google Patents

Abstract

FIELD: X-ray engineering. SUBSTANCE: radiator includes X-ray source with electron gun, anode-target, zone to extract X-radiation and power supply source. Radiator is fitted with coaxial resonator, electron gun is placed in space near free butt of internal conductor of resonator. Flight-path tube with zone to extract X-radiation is linked through hole in resonator uniaxially to cover of resonator from outside. Anode-target is installed in butt of this tube. Resonator and tube are vacuumed, superhigh-frequency oscillator is connected through hole in cover of resonator close to base internal conductor and is utilized as power supply source. In compliance with another variant power supply source can be disconnected and magnetron is employed in its capacity, magnetic system can be placed coaxially with flight-path tube. Part of flight-path tube including its butt are made of material transparent to X-rays. EFFECT: resistance to breakdown, increased reliability, durability and compactness. 4 cl, 1 dwg

Description

The invention relates to the field of x-ray technology, in particular to x-ray emitters used in medicine, viewing customs complexes, in security devices (security, etc.)
Known x-ray emitter in the composition of the x-ray apparatus "Baltospot" GFD-306 [1], in the casing of which is placed a traditional x-ray tube and some elements of the power circuit. External insulation of the X-ray tube is ensured by filling the casing with SF6 gas. The electrical strength of an X-ray lamp depends on the inside of the lamp atmosphere, the state of the electrodes, and external insulation. During the operation of such emitters, there are frequent cases of SF6 leakage and thereby loss of external insulation. In this case, as well as after replacing a failed X-ray tube, before a new filling of the casing, it needs to be dried for a long time using vacuum pumping and heating. Bulky are the power sources of the emitter (as well as the elements of the power circuit that are part of the emitter itself).

 For the prototype, you can take another type of x-ray emitter [2], which also uses a traditional x-ray tube. Such a radiator consists of a tank internally lined with lead, a built-in X-ray tube with anode rotation mechanism, and a high-voltage cable input.

 The external insulation of the x-ray tube is ensured by the fact that the tank is filled with transformer oil, which is previously evacuated. The tank has a glass "window" for outputting X-ray radiation. The x-ray tube has an electron gun, a target anode and a “window” (glass bottle) for outputting x-ray radiation. The tank with its contents has a significant mass, its power sources are bulky. When replacing the X-ray tube, the transformer oil must be drained, then refilled, previously evacuated. The breakdown resistance of the emitter is limited and is achieved through the use of bulky means of external insulation. Reliability and durability of the emitter are also limited.

 The proposed x-ray emitter of a fundamentally new type does not require external insulation, which simplifies the problem of the electric strength of both the emitter and its power circuit, which becomes significantly less high-voltage and bulky. The emitter has increased breakdown resistance, increased reliability and durability, more compact.

 An x-ray emitter is proposed that contains an x-ray source with an electron gun, a target anode and an x-ray output zone connected to a power source, characterized in that the emitter is equipped with a coaxial resonator, an electron gun is placed in the cavity at the free end of the inner conductor of the resonator along its axis, opposite it is connected coaxially to the resonator cap through a hole in the resonator through a passage pipe with an X-ray output zone, an anode is installed at the end of this pipe the target, the resonator and the tube being evacuated, and a microwave generator connected to the resonator through a hole in the cavity cover at the base of the inner conductor and through a dielectric window.

In options:
- the power source is made detachable from the resonator with the possibility of regulating communication with it to change the level of microwave power introduced into the resonator;
- a magnetron is used as a power source;
- coaxial span pipe placed magnetic system;
- part of the span pipe, including its end, is made of the most transparent material for x-ray radiation.

 When using microwave voltage to accelerate electrons, the electric strength of the gap increases many times as compared to applying a constant or pulsed voltage from a high voltage source to this gap. With a low voltage supply of the microwave generator, problems with the electric strength of the power system also do not arise. The absence of a high-voltage insulator at the resonator completely removes the problem of electric strength (external insulation) for the resonator. In traditional X-ray emitters, the insulator of a traditional X-ray tube significantly reduces the electric strength of the tube (sputtering, leakage, glass breakdown during breakdowns) and the emitter as a whole.

 From the above it is clear that the expected durability and reliability of the proposed emitter will be significantly higher than that of traditional emitters.

 When the microwave source is detachable from the resonator using the coupling loop, it is possible to control the level of microwave power introduced into the resonator and thereby the level of the accelerating voltage in the cavity gap and the x-ray energy. At the same time, the microwave source mode can be kept practically unchanged. In the case of an unlikely failure of the microwave source, its replacement is extremely simple (without problems with transformer oil or SF6 gas). The failure of the resonator elements (electron gun, target anode) is even less likely. But in this case, there is a gain: the microwave source is saved.

 The use of a magnetron as a power source in some cases is preferable due to its high efficiency, durability, simple design, and low cost.

 To obtain sharp-focus x-ray radiation, a magnetic system may be needed that is located coaxially with the span tube.

 In order for the x-ray radiation to exit from the target to reflection or for outputting the directed orthogonal axis of the x-ray resonator, the part of the span tube adjacent to the target anode is made of the material most transparent to x-ray radiation (beryllium, aluminum).

 For a shooting target, the end of the span pipe is made of the same materials, and the target (of tungsten) is sprayed with a thin layer on the inner side of the end.

The invention is illustrated in the drawing, which shows a structural diagram of the proposed x-ray emitter. The emitter design includes the following elements:
1 - resonator
2 - external conductor of the resonator,
3 - inner conductor of the resonator,
4 - resonator cap at the base of the span pipe,
5 - resonator cap at the base of the inner conductor,
6 - electron gun,
7 - span pipe
8 - target anode,
9 - part of the span tube adjacent to the target anode ("window" for outputting x-ray radiation),
10 - microwave generator (microwave generator),
11 - hole in the cover of the resonator at the base of the inner conductor (for input into the resonator microwave power),
12 - device for maintaining high vacuum in the resonator,
13 is a dielectric vacuum window for input into the resonator microwave power,
14 - connection loop of the microwave generator with the resonator,
15 - magnetic system.

 The order of operation of the emitter is as follows.

 From the microwave generator 10, through the hole 11 in the cavity cover 5 at the base of the inner conductor using the loop 14 and through the dielectric vacuum window 13 into the resonator 1, formed by parts 2, 3, 4, 5, microwave power is supplied. At the gap of the resonator formed by the free end of the inner conductor 3 and the cover 4 of the resonator, the voltage of microwave oscillations appears.

 When the electron gun 6 is turned on, an electron stream exits from it, accelerating in the aforementioned cavity gap and flying in the passage pipe 7 to the target anode 8. When the target is bombarded with an electron stream, the energy of this stream is converted into X-ray energy. Depending on the purpose of the emitter, the x-ray radiation is output in the direction opposite to the direction of the electron beam at an angle to the axis of the resonator, panoramicly through part 9 of the span tube adjacent to the target anode (reflecting the target), or through the same part 9 of the span tube directionally, orthogonal to the axis resonator. In the case of a shooting target, x-ray radiation is output through the end of part 9 of the span tube.

 By changing the size of the loop 14, immersing it in the resonator or turning the loop, you can adjust the level of microwave power supplied to the resonator 1 without changing the mode of the microwave generator 10. This adjustment allows you to change the level of microwave voltage at the cavity gap, the energy of accelerated electrons and thereby the level x-ray radiation, which is necessary when switching from one to another emitter operating modes. The device 12 ensures that a high vacuum is maintained in the resonator 1. The magnetic system 15 provides sharp-focus x-ray radiation. Due to the fact that the target anode is remote using the span tube 7 from the cover 4 of the resonator 1, it became possible to conveniently place removable air or liquid cooling systems of the target anode (not shown).

 The market of x-ray machines, x-ray emitters and power sources which can be replaced by those proposed in the application, is vast.

 In Russia, viewing complexes at airports (and in other cases) lack at least 500 units. And about the same, approximately, is in operation and may require replacement.

 The number of purchases for the offices of entrepreneurs of X-ray complexes is growing, which allows them to be checked for the presence of explosives before opening the mail packages.

 The proposed x-ray emitter and a series based on it can cover a significant part of the need for emitters, cheaper, more reliable, more durable with easily replaceable parts or easily repairable. This will significantly reduce the cost of their operation, free up funds for expanding new purchases.

 The possibilities of export deliveries are not considered here, and the given examples concern only a small part of the types of X-ray machines, complexes, and their application areas.

 The creation and production of a number of new-type X-ray emitters will significantly increase the share of civilian products among microwave devices and devices.

Sources of information
1. Catalog of the company "Balteau" (Belgium), 1997

 2. X-ray engineering (reference book), book 1, M., Engineering, 1992, p.136, Fig. 36a.

Claims (5)

 1. An x-ray emitter comprising an x-ray source with an electron gun, a target anode and an x-ray output zone connected to a power source, characterized in that the emitter is equipped with a coaxial resonator, an electron gun is placed in the cavity at the free end of the inner conductor of the resonator along its axis, opposite to its cathode, a span pipe with an X-ray output zone is connected coaxially to the resonator cap from the outside through the hole in the resonator, anode-mounted at the end of this pipe Shade, and wherein the resonator tube is evacuated, and a power source connected to the resonator a microwave generator through a hole in the lid at the inner cavity conductor and the base through the dielectric window.  2. The x-ray emitter according to claim 1, in which the power source is detachable from the resonator with the ability to regulate communication with it to change the level of microwave power introduced into the resonator.  3. An x-ray emitter according to any one of claims 1 and 2, in which a magnetron is used as a power source.  4. An x-ray emitter according to any one of claims 1 to 3, in which a magnetic system is placed coaxially to the span tube.  5. X-ray emitter according to any one of claims 1 to 4, in which part of the span tube, including its end, is made of the most transparent material for x-ray radiation.