The cathode material for high-current ion accelerator

 

(57) Abstract:

The material is intended for the manufacture of cathode high current ion accelerator. The material contains, wt%: aluminum 17 - 20, silica, 2 to 4, Bor 16 - 19, graphite 27 - 31, titanium - rest. The cathode reduces the threshold elasmobranchii and improve the current pulse.

The invention relates to the field of production of powerful ion beams (MIP) and can be used in accelerators operating in continuous and pulsed modes.

Known cathode material of the following composition, wt.%: copper 20, the silicon of 0.5, tungsten - other [1]. The disadvantage of this cathode material is sufficiently high current arc - 200 A.

Closest to the proposed invention to the technical essence and the achieved result is a cathode material for high-current ion accelerator (SIU), is made of graphite [2]. This cathode allows to obtain beams of carbon ions current density of 60 A/cm2when the average voltage on the diode 300 kV/cm and pulse duration 60 Hc (half max).

The disadvantages of such a cathode are high energy threshold elasmobranchii and limit the functionality of accelerators porneste materials. The irradiation surface materials carbon ions with the aim of improving service performance suitable only for certain types of steels. In most cases, when objects are alloys based on Nickel or copper, as well as semiconductors, introduction of carbon ions is not preferred.

The aim of the present invention is to reduce the energy threshold of elasmobranchii and increased functionality of the accelerator.

This objective is achieved in that the cathode is manufactured by powder metallurgy from a composite material, comprising, in wt.%:

Aluminum (PA - 4) - 17 - 20

Silicon (PC - 30) - 2 - 4

Boron (PTS - 4) - 16 - 19

Graphite (PG - 1) - 27 - 31

Titanium (PTOM) - Rest

This composition allows to obtain the working surface of the cathode with high electrical and physical characteristics required for the excitation of the discharge and the formation of near-surface plasma density sufficient to rapid homogeneous filling of the diode and retrieving large currents. Determining a physical parameter of the working surface of the cathode material is the work function. The reduction of the work function provides snizeni the excess emissions and consequently the current density at a lower energy level, i.e. at a lower threshold voltage. The latter is determined by the magnitude of the first pulse of negative polarity, used for creating a plasma in the diode. The lower threshold elasmobranchii need for a more uniform filling of the diode plasma, which ensures stable high intensity current pulse at the lower energy process.

Extended functional capabilities of the accelerators provided by the fact that the elements included in the composition, are widely used in the technology of ion-plasma surface modification of materials, which is the improvement of physical-mechanical, optical, corrosion properties of the material. Using the link performance characteristics - physico-chemical state of the surface, we can qualitatively predict the change of this state, and hence the operating characteristics of the surface of the workpiece during implantation those or other ions. So for high-speed steels and hard alloys, it is desirable to carry out dispersion hardening due to the formation of new phases of borides, carbides and borosilicate [3, 4]. In this regard, the use of the proposed composite cathode in uchitelyah ru is processed by ion beams to improve performance.

Thus, the use of multi-element composite cathode in uchitelyah opens up the possibility of their multipurpose use and at the same time provides a significant reduction of energy consumption for plasma generation.

Example. The cathode representing the shape of a sector of the inner surface of the cylinder, with a radius of 140 mm, height 40 mm made of hydrodynamic compaction of powders of titanium, boron, graphite, silicon and aluminum, followed by sintering in a vacuum furnace type SNWA. The sintering temperature was selected such as to ensure the appearance of the liquid phase to accelerate the sintering process. The presence of elements of the solid phase titanium and boron creates the skeleton of these particles, which prevents the workpiece cathode to sit down or to change its shape during sintering. After turning the cathodes used in high-current accelerator to obtain a powerful ion beam complex composition of nanosecond duration. Testing the threshold voltage elasmobranchii conducted on the accelerator "Tone" [2].

The density measurement was carried out at the same accelerating voltage of 300 kV. The best results are achieved when using a graphite cathode in which the R data should that multi-component cathode of the proposed structure reduces the amplitude of the voltage in the first impulse to 86 - 90 kV with a slight decrease of the current density. The result is the value of the coefficient of the output (the ratio of current density to voltage in the first pulse) is increased 1.5 times compared with the corresponding value of the coefficient of the output when using a graphite cathode.

References:

1. U.S. patent N 1477794, C 23 C 15/00, 1967.

2. Isakov, I. F. , Lopatin C. S., Pushkarev A. I., Remnev, that is, the Modified source of powerful ion beams "Temp". Proceedings of the IV all-Russian conference on modification of properties of structural materials by charged particle beams", Tomsk, 1996, S. 105 - 106.

3. Solow Century A. the Choice of implanted ions and the optimal modes of ion doping of metals and alloys. // Proc. "Modification of properties of structural materials by charged particle beams", Tomsk, 1994, T. 1, S. 64 - 67.

4. Agricultural Rissel, I. Ruge. Ion implantation. - M.: Nauka, 1983, 359 S.

The cathode material for high-current ion accelerator containing graphite, characterized in that it additionally contains aluminum, silicon, boron, titanium in the following ratio component

 

Same patents:

The invention relates to Electrophysics, specifically to the field of acceleration, transport, and transformation of charged particle beams

The invention relates to accelerator technology and can be used when creating a pulsed high-current relativistic electron accelerators microsecond range

The invention relates to accelerator technology and can be used when creating a pulsed high-current relativistic electron accelerators microsecond range

Electronic device // 2102812

Electronic device // 2102812

Vacuum microtriode // 2097869

The invention relates to a plasma emission electronics, in particular, to the design of the plasma ion and electron emitters continuous action with a large surface-based volume discharge with cold electrodes, and can be used for heat treatment in vacuum: during sintering products from metal powders, brazing, hardening, as well as in technological processes, for example, obezvozhivanija parts with subsequent activation and coating, when required combination of electron and ion beams to be solved in a single cycle by switching the polarity of the accelerating particle voltage

The invention relates to electronic equipment, in particular, to the vacuum instrumentation, and can be used for the manufacture of cold cathodes

Field emission site // 2094890
The invention relates to the field of microelectronics, in particular, to field emission sources of electrons in matrix structures from planar-end field emission cells

Field emission site // 2094890
The invention relates to the field of microelectronics, in particular, to field emission sources of electrons in matrix structures from planar-end field emission cells

The invention relates to x-ray optics, in particular, to a device for reflection, rotation, divide, focus and monochromatization of x-ray flux and can be used for carrying out processes rentgenovskoi lithography, x-ray microscopy, x-ray spectroscopy, as well as in astronomy, physics, biology, medicine and other fields technique that uses x-rays
The invention relates to a thin film coatings in a vacuum, in particular protective, wear-resistant and decorative coatings on articles of various materials
Up!