RU2777013C1 - Gas-filled neutron tube - Google Patents

Abstract

FIELD: sealed neutron tubes.

SUBSTANCE: invention relates to sealed neutron tubes and can be used in neutron generators for the study of geophysical and commercial wells, analysis of the composition of substances, radiation therapy. In a sealed neutron tube, including a tubular high-voltage insulator, at one end of which the accelerating electrode and target are hermetically fixed, and at the other end, a ring is hermetically fixed along its outer diameter. A pipe is attached to the ring along its inner diameter coaxially with it, an anticathode in the form of a disk with a hole for extracting ions is fixed at the opposite end of the pipe. Inside the pipe, coaxially with it, there is a glass, in which there is a cylindrical magnet. The edges of the glass are hermetically connected to the ring, in the cavity of the pipe between the anticathode and the bottom of the glass, an anode is placed coaxially with it, having the shape of a ring. A ring magnet is installed on the ring, pressed with one pole to the ring. A removable cover is pressed against the opposite pole of the magnet, the cylindrical magnet rests against the cover in its central part. The poles of cylindrical and ring magnets pressed against the cover are opposite. The cover, ring, tube and anti-cathode are made of soft magnetic material, the glass is made of non-magnetic material.

EFFECT: increase in the neutron flux of the tube.

1 cl, 1 dwg

Description

The invention relates to sealed neutron tubes and can be used in neutron generators for the study of geophysical and field wells, analysis of the composition of substances, radiation therapy.

Known sealed neutron tube containing a tubular high-voltage insulator placed at one end of the ion source with an anti-cathode with a hole for extracting ions, an accelerating electrode and a target placed at the other end. Patent of the Russian Federation No. 2540983, IPC H05H 3/06, 02/10/2015. The disadvantage of the neutron tube is the low neutron flux due to the significant range of ions from the anticathode to the target. The ions that have passed the hole in the anticathode are accelerated towards the target between the anticathode and the accelerating electrode and then move towards the target without acceleration. The ion range is approximately equal to the length of the high-voltage insulator and significantly exceeds the length of the accelerating gap between the anticathode and the accelerating electrode. This leads to unjustified losses in the ion beam on that part of the path where there is no acceleration, and as a result, to a decrease in the neutron flux.

Known sealed neutron tube containing a tubular high-voltage insulator placed at one end of the source of ions with an anticathode with a hole for extracting ions; in the volume of the insulator, coaxially with it, the target is placed. Patent of the Russian Federation No. 2366030, IPC H01J 27/04, 08/27/2009. The disadvantage of this tube is the large distance from the target to the end of the tube, which reduces the neutron flux density on the irradiated sample.

Known sealed neutron tube, including a tubular high-voltage insulator, on one end of which the accelerating electrode and target are hermetically fixed, and on the other end hermetically, along its outer diameter, a ring is fixed; a pipe is attached to the ring, along its inner diameter, coaxially with it, at the opposite end of the pipe, an anti-cathode in the form of a disk with a hole for extracting ions is fixed, inside the pipe, coaxially with it, a glass is placed in which a cylindrical magnet is located, the edges of the glass are sealed connected to the ring, in the cavity of the pipe, between the anticathode and the bottom of the glass, coaxially with it, there is an anode having the shape of a ring. Patent of the Russian Federation No. 2583000, IPC H05H 3/06, 04/27/2016. This technical solution is accepted as a prototype. The disadvantage of the prototype is the low neutron flux due to the low combustion efficiency of the discharge in the region of the anticathode. The prototype uses an end magnet placed on the outside of the cathode. The magnetic field strength is maximum at the cathode surface and drops sharply towards the anticathode surface. For this reason, the gas discharge burns mainly at the cathode. This reduces the efficiency of discharge combustion in the region of the anticathode hole and reduces the extracted ion current. A decrease in the ion current leads to a decrease in the tube neutron flux.

The proposed technical solution eliminates this disadvantage.

The technical result is an increase in the neutron flux of the tube.

The technical result is achieved by the fact that in a sealed neutron tube, including a tubular high-voltage insulator, at one end of which the accelerating electrode and the target are hermetically fixed, and at the other end a ring is hermetically fixed along its outer diameter, a pipe is attached to the ring along its inner diameter coaxially with it , an anti-cathode in the form of a disk with a hole for extracting ions is fixed at the opposite end of the pipe ring, a glass is placed coaxially with it inside the pipe, in which a cylindrical magnet is located, the edges of the glass are hermetically connected to the ring, in the cavity of the pipe between the anticathode and the bottom of the glass is placed coaxially with it an anode having the shape of a ring, a ring magnet is installed on the ring, pressed with one pole to the ring, a removable cover is pressed to the opposite pole of the magnet, a cylindrical magnet rests against the cover in its central part. The poles of cylindrical and ring magnets pressed against the cover are opposite. The cover, ring, tube and anti-cathode are made of soft magnetic material, the glass is made of non-magnetic material. Thanks to this solution, the magnetic field strength increases in the area of the hole in the anticathode, in its central part, the pole of the cylindrical magnet closes with the pole of the ring magnet, the concentration of ions in this area increases and the ion current increases, which leads to an increase in the neutron flux of the tube.

The essence of the invention is illustrated by a drawing, which schematically shows a sealed neutron tube, where 1 is a tubular high-voltage insulator, 2 is an accelerating electrode and target, 3 is a ring, 4 is a pipe, 5 is an anti-cathode, 6 is a glass, 7 is an anode, 8 is a cylindrical magnet, 9 - ring magnet, 10 - cover. The tube includes a high-voltage tubular insulator 1, at one end of which the accelerating electrode and target 2 are hermetically fixed. the end of the pipe 4 opposite to the ring is fixed with an anti-cathode 5 in the form of a disk with a hole for extracting ions. Inside the tube 4, coaxially with it, there is a cup 6, in which there is a cylindrical magnet 9. The edges of the cup 6 are hermetically connected to the ring 3. In the cavity of the tube 4 between the anticathode 5 and the bottom of the cup 6, an anode 7 is placed coaxially with it, having the shape of a ring. An annular magnet 9 is mounted on ring 3, pressed with one pole to ring 3. A removable cover 10 is pressed to the opposite pole of magnet 9. Cylindrical magnet 8 abuts against cover 10 in its central part. The poles of the cylindrical magnet 8 and the ring magnet 9 pressed against the cover 10 are opposite. Cover 10, ring 3, tube 4 and anticathode 5 are made of soft magnetic material. Glass 6 is made of non-magnetic material.

The device works as follows.

A positive voltage relative to the cathode and anticathode is applied to the anode of the ion source. A magnetic field is created in the gas-discharge chamber between the cathode and anticathode, end and ring magnets. The magnetic lines of force of one of the poles of the ring magnet are closed with the opposite pole of the cylindrical magnet in the gap between the cathode and anticathode. Such a closure is provided by a ring, a pipe and an anticathode made of a magnetically soft material, which leads to an increase in the magnetic field strength in the region of the anticathode hole. The cover made of soft magnetic material ensures the closing of the opposite poles of the ring magnet and the cylindrical magnet, which reduces the scattering of magnetic lines outside the volume of the ion source. The efficiency of discharge burning in the area of the anticathode hole increases, which leads to an increase in the ion current and the neutron flux of the tube. Through the hole in the anticathode, the ions from the discharge enter the volume of the tubular high-voltage insulator and are accelerated towards the target. Neutrons are produced in the target as a result of thermonuclear reactions.

Claims (1)

A sealed neutron tube, including a tubular high-voltage insulator, at one end of which the accelerating electrode and target are hermetically fixed, and at the other end a ring is hermetically fixed along its outer diameter, a pipe is attached to the ring along its inner diameter coaxially with it, at the opposite end of the pipe is fixed an anticathode in the form of a disk with a hole for extracting ions, inside the tube coaxially with it there is a glass, in which there is a cylindrical magnet, the edges of the glass are hermetically connected to the ring, in the cavity of the pipe between the anticathode and the bottom of the glass, an anode is placed coaxially with it, having the shape of a ring, which differs topics that a ring magnet is installed on the ring, pressed with one pole to the ring, a removable cover is pressed to the opposite pole of the magnet, a cylindrical magnet rests against the cover in its central part, the poles of the cylindrical and ring magnets pressed to the cover are opposite, cover, ring, pipe and anticathode are made of soft magnetic material, the glass is made of non-magnetic material.

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