RU224578U1 - Sealed neutron tube - Google Patents

Abstract

The utility model relates to sealed neutron tubes and can be used in neutron generators for studying geophysical and production wells, analyzing the composition of substances, and radiation therapy. The neutron tube contains a tubular insulator, at one end of which a target and an accelerating electrode with a central hole for the passage of ions are hermetically sealed; at the other end, an ion source made in the form of two coaxially placed glasses is fixed to the axially accelerating electrode. In this case, the bottom of the larger glass facing the accelerating electrode is an anticathode with a central hole for extracting ions. The bottom of the smaller glass facing the anti-cathode is the cathode. The edges of the smaller glass are hermetically connected to the end of the tubular insulator through a flange. The flange has pressure seals. Between the cathode and anti-cathode, coaxially with the central hole, there is an anode mounted on sealed leads through a pipe passing between the walls of the glasses. The wall of the larger glass is perforated. The technical result is an increase in the neutron flux. 2 ill.

Description

The utility model relates to sealed neutron tubes and can be used in neutron generators for studying geophysical and production wells, analyzing the composition of substances, and radiation therapy.

A sealed neutron tube is known, containing a tubular high-voltage insulator with an ion source placed at one end 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 this tube is the low neutron yield. The anode of the tube is fixed to one current lead; this does not allow the anode to be aligned with the hole in the anti-cathode during operation of the tube. Deviation of the anode from the axis of the hole in the anti-cathode leads to deterioration in the focusing of the ion beam, its displacement relative to the tube axis and contact with the edges of the accelerating electrode. Which in turn will lead to a decrease in the neutron yield.

A gas-filled neutron tube is known, including a tubular high-voltage insulator, at one end of which an accelerating electrode and a target are hermetically fastened, and at the other end a ring is hermetically fastened along its outer diameter, a pipe is attached to the ring along its inner diameter coaxially with it, at the end of the pipe opposite the ring the anticathode is fixed in the form of a disk with a hole for extracting ions, a glass containing a cylindrical magnet is placed inside the pipe, coaxially with it, the edges of the glass are hermetically connected to the ring, and an anode in the shape of a ring is placed in the cavity of the pipe between the anticathode and the bottom of the glass, coaxially with it. Patent of the Russian Federation No. 2777013, IPC H05H 3/06, 08/01/2022. The disadvantage of this tube is the low neutron yield. The anode of the tube is fixed to one current lead, which does not allow the anode to be aligned with the hole in the anti-cathode during operation of the tube. Deviation of the anode from the axis of the hole in the anti-cathode leads to deterioration in the focusing of the ion beam, its displacement relative to the tube axis and contact with the edges of the accelerating electrode, which in turn will lead to a decrease in the neutron yield.

A sealed neutron tube is known, containing a tubular insulator, at one end of which a target and an accelerating electrode with a central hole for the passage of ions are fixed, and an ion source is axially fixed at the other end (Fig. 1).

The ion source is made in the form of two coaxially placed glasses, the bottom of the larger glass is an anti-cathode with a central hole for extracting ions, the bottom of the smaller glass is a cathode, the edges of the smaller glass are hermetically connected to the end of the insulator through a flange, there are sealed leads in the flange, between the cathode and the anticathode coaxially with The central hole houses the anode, fixed to the sealed leads through a pipe passing between the walls of the glasses. Patent of the Russian Federation No. 2583000, IPC H05H 3/06, 04/27/2016. This technical solution was adopted as a prototype.

The disadvantage of the prototype is the low neutron flux of the tube. In the prototype, between the cathode and anti-cathode, an anode is placed coaxially with the central hole, secured to sealed leads through a pipe passing between the walls of coaxially placed cups. There is a structural capacitance between the pipe and the wall of the larger glass, which leads to an increase in the duration of the front of the anode voltage pulse. The ignition time of the discharge in the ion source increases, which leads to an increase in the duration of the front of the neutron pulse. This leads to a decrease in the duration and increase in the delay of the neutron pulse, and the ion current on the target decreases. A decrease in the ion current leads to a decrease in the neutron flux of the tube.

The proposed technical solution eliminates this drawback.

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

The technical result is achieved by the fact that a sealed neutron tube containing a tubular insulator, at one end of which a target and an accelerating electrode with a central hole for the passage of ions are hermetically sealed; at the other end, an ion source made in the form of two coaxially placed glasses is fixed to the axially accelerating electrode, with in this case, the bottom of the larger glass facing the accelerating electrode is an anticathode with a central hole for extracting ions; the bottom of the smaller glass facing the anti-cathode is the cathode, the edges of the smaller glass are hermetically connected to the end of the tubular insulator through a flange, the flange has sealed leads, an anode is placed between the cathode and the anticathode coaxially with the central hole, secured to the sealed leads through a pipe passing between the walls of the glasses, the wall of the larger one the glass is perforated.

The essence of the utility model is illustrated by the drawing (Fig. 2), which schematically shows a sealed neutron tube, where:

1 - tubular insulator;

2 - target;

3 - accelerating electrode;

4 - glass of larger diameter with a perforated wall;

5 - anode;

6 - pipe;

7 - glass of smaller diameter;

8 - flange;

9 - pressure seals.

The device contains (Fig. 2) a tubular insulator 1, at one end of which a target 2 and an accelerating electrode 3 with a central hole for the passage of ions are hermetically sealed. In the general case, the accelerating electrode 3 may be located outside the volume of the tubular insulator 1. At the other end of the tubular insulator 1, an ion source is fixed to the axially accelerating electrode 3, made in the form of two coaxially placed glasses 4 and 7. The bottom of the larger glass 4, facing the accelerating electrode 3, is an anticathode with a central hole for ion extraction. The bottom of the smaller glass 7 facing the anti-cathode is the cathode. The edges of the smaller glass 7 are hermetically connected to the end of the tubular insulator 1 through the flange 8, which is a sufficient condition for sealing the tubular insulator 1 from the side of the ion source. In the flange 8 there are sealed leads 9, an anode 5 is placed between the cathode and anticathode coaxially with the central hole. Anode 5 is fixed to sealed leads 9 through pipe 6. Pipe 6 passes between the perforated wall of the glass 4 and the wall of the glass 7. The perforation of the wall of the larger glass can be any, for example, made in the form of holes of arbitrary shape.

In general, the anode 5 can be fixed to the pipe 6 in any way, and their diameters may differ.

The device works as follows.

An accelerating voltage is applied to the accelerating electrode 3 and target 2 relative to the coaxially placed cups 4 and 7. The edges of the cup 7 are connected to the end of the tubular insulator 1 through a flange 8. On the flange 8 there are arbitrarily located sealed leads 9. To the anode 5 of the ion source, fixed coaxially with the central a hole in the bottom of glass 4 on pipe 6, a voltage positive relative to the cathode and anti-cathode is supplied. A discharge is ignited in the gas-discharge chamber between the cathode and anti-cathode. Perforating the wall of the glass 4 reduces the structural capacity of the ion source, which leads to a decrease in the duration of the front of the anode voltage pulse. The ignition time of the discharge in the ion source is reduced, which leads to a decrease in the duration of the front of the neutron pulse. The duration of the neutron pulse increases and the delay decreases, and the ion current on target 2 increases. An increase in the ion current leads to an increase in the neutron flux of the tube. Through a hole in the anti-cathode, ions from the discharge enter the volume of tubular insulator 1, are accelerated, pass through the hole in the accelerating electrode 3 and reach target 2. In target 2, neutrons are produced as a result of thermonuclear reactions.

Thus, the stated technical result is achieved, namely an increase in the neutron flux of the tube.

Claims (1)

A sealed neutron tube containing a tubular insulator, at one end of which a target and an accelerating electrode with a central hole for the passage of ions are hermetically fastened; at the other end, an ion source is fixed to the axially accelerating electrode, made in the form of two coaxially placed glasses, with the bottom facing the accelerating electrode the larger glass is an anticathode with a central hole for extracting ions; The bottom of the smaller glass facing the anti-cathode is the cathode, the edges of the smaller glass are hermetically connected to the end of the tubular insulator through a flange, the flange has sealed leads, between the cathode and the anticathode, coaxially with the central hole, there is an anode mounted on the sealed leads through a pipe passing between the walls of the glasses, characterized in that that the wall of the larger glass is perforated.