The device for generation of soft x-rays

 

(57) Abstract:

Application: radiation physics. The device can be used in the development of powerful large-aperture emitters of soft x-rays (MRI) quantum energy of 50 eV to 5 Kev for various scientific applications. The inventive device for generating MRI, containing consistently located the driver, optically thin target bremsstrahlung and reflector electrons, unlike the prototype driver made in the form of a radiation source hard-quanta. An additional difference may be that the reflector of the electrons is made in the form of a source of a magnetic field parallel to the surface of the target bremsstrahlung. The technical result is to increase power output device for generating MRI due to a driver of another type, not having restrictions on the amount of power. 1 C.p. f-crystals, 1 Il.

The invention relates to radiation physics and can be used in the development of powerful large-aperture emitters soft x-ray study (MRI) quantum energy of 50 eV to 5 Kev for various scientific applications.

A device for generating rentgenovskoj the se) and the magnetic system of the reversal of the beam [1] (Grishin, C. K., The Ishkhanov B. S., "an Efficient source of bremsstrahlung with multiple crossing a thin target electron beam", Vestnik MGU, ser. 3, 1996, 1, S. 83-86).

A disadvantage of this device is the low yield of MRI.

It is also known device for generating TECHNIQUES described in [2] (Sanford T. W. L, Halbein J. A., "Potential enhancement of warm X-ray dose from a reflexing bremsstrahluhg diode", IEEE Transactions on Nuclear Science, 1995, v. 42, 6, p. 1902-1909). This device contains consistently located electronic diode as the driver, optically thin bremsstrahlung target (foil) and the reflector of the electrons in the form of additional electrode, providing a multiple passage of the electrons through the foil. This device is chosen for the prototype.

However, the known device has a physical limit on power generation, since the use of electronic diode as the driver current, the latter cannot exceed the value defined limiting current Childe-Langmuir, therefore, claimed in [2] values of the current in the diode (60 MA) at an accelerating voltage of 5 MB) can hardly be achieved. Indicate that the increase of accelerating voltage in addition to increasing the current driver leads to a shift of the spectrum of x-rays in more than the invention is to eliminate restrictions on the amount of power the driver.

The technical result consists in increasing the power output device for generating MRI due to a driver of another type, not having restrictions on the amount of power.

This result is achieved by the fact that the device for generating MRI, containing consistently located the driver, optically thin target bremsstrahlung and reflector electrons, unlike the prototype driver made in the form of a radiation source hard-quanta. An additional difference may be that the reflector of the electrons is made in the form of a source of a magnetic field parallel to the surface of the target bremsstrahlung.

The proposed device is based on the knocking hard-quanta driver from the target flows Compton electrons (KE) and electron-positron pair (e--e+-pairs) and ensuring their repeated passing through the target. While the target simultaneously with the role of source brake MRI plays a role-emitter CE and e--e+-pairs. In fact, the proposed device is a Converter-breeder hard radiation in MRI, as one of TBE or one e--e+couples can be a large number of quanta the ants do not apply any force, there is no physical limitations on the power driver, which explains the achievable technical result.

To provide a multiple pass CE and e--e+-nap through the target it is convenient to use a device that creates a magnetic field near the target, parallel to her. Indeed, electrostatic reflective system, similar to [2], has overshadowed the target driver, and in addition, to reflect, say, electrons with an energy of 5 MeV would be required to apply for electrostatic reflectors potential value, lesser - 5 MB relative to the target, while the magnetic field, for example, only 1 kgf able to wrap such electrons only on the radius of a few centimetres. Thus, the magnetic system of the reflection of electrons and positrons to use preferably, however, the use of electrostatic or combined reflection is not excluded.

The drawing represents an example of a circuit implementation device for generating MRI and explains how it works.

In the drawing: 1 - driver, 2 - source of a magnetic field (shown closed magnetic field lines), 3 - target bremsstrahlung large the electron, e--e+- trajectory pair of electron and positron.

Driver 1, which is the source of hard-quanta, can be performed, for example, in the form of a radioactive element, in the form of high-current electron accelerator operating in the mode of generation of bremsstrahlung radiation or nuclear explosive device, which is also a source of hard-quanta. The first example is possible if the proposed device for the generation of MRI is to be used in continuous mode, the last two examples refer pulse mode operation.

The source of the magnetic field 2 may be made in the form of permanent magnets for continuous operation or in the form of a solenoid, as shown in the drawing, for pulse mode operation. To power the solenoid need a power supply, which can be used in the capacitor Bank with the managed switching (not shown).

As optically thin target 3 bremsstrahlung using a metal foil made of a material with high atomic number, such as tantalum. The foil thickness is chosen according to the desired size lower bounds in the spectrum of MRI.

Devices the static current in the solenoid 2, exciting magnetic field parallel to the target 3. After reaching the magnetic field values required for reversal of charged particles start driver 1 which emits a pulse hard-quanta.

Hard-quanta knock from the target 3, the flow of charged particles in the form of EC and e--e+-pairs. These particles are wrapped by the magnetic field of the solenoid 2, repeatedly passing through the target 3 and generating multiple MRI.

1. The device for generation of soft x-ray radiation, containing consistently located the driver, optically thin target bremsstrahlung and reflector electrons, characterized in that the driver is made in the form of source hard-quanta.

2. The device under item 1, characterized in that the reflector electrons in the form of source magnetic field parallel to the surface of the optically thin target bremsstrahlung.

 

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