A compact d‑d neutron generator

Abstract

The invention discloses a compact type D-D neutron generator applicable to neutron activation analysis or neutron radiography. The compact type D-D neutron generator comprises a vacuum cavity body, an ion source system, a beam extraction acceleration system, a target system, a high voltage feed system and a vacuum pump system, wherein ion beams generated by the ion source are extracted, accelerated and subjected to a D-D nuclear fusion reaction with a deuterium target on the target system to discharge neutrons; the two ends of the vacuum cavity body are connected with the ion source system, the beam extraction acceleration system, the target system and the high voltage feed system through an ion source positive electrode flange and a second flange respectively; the vacuum cavity body, the ion source positive electrode flange and the high voltage feed system are sealed through an O-shaped ring; and the ion source is a dual-plasma source, and the D gas is pumped in the ion source. The neutron yield can be more than 1*108s(1) magnitude, and the ion source, or target sheet and other system and internal parts can be replaced quite conveniently; and meanwhile, the usage cost is greatly lowered.

Description

technical field [0001] The invention relates to a neutron generator, in particular to a compact D-D generator suitable for neutron activation analysis or neutron photography. Background technique [0002] Intensive deuterium-deuterium (D-D) and deuterium-tritium (D-T) fusion reaction accelerator neutron source is an important single-energy neutron source (neutron generator for short), which can be widely used in nuclear data measurement, nuclear fusion reactor basic research, military industry Basic research, fast neutron application technology and other aspects. The characteristics of D-D and D-T fusion reactions are that at lower D beam energy, there is a larger reaction cross section, that is, a low-energy accelerator can be used to accelerate D ion beams to bombard deuterium titanium (TiD) targets or tritium titanium (TiT) targets. Deuterium-deuterium (D-D) or deuterium-tritium (D-T) fusion reactions produce intense fast neutrons. [0003] At present, there are two dev...

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Problems solved by technology

Theoretically speaking, the above four implementation schemes can realize DD neutron yield greater than 10 11 the s -1 , even up to 10 12 the s -1 , but the beam power on the target of the above scheme is too large, and the oil cooling mentioned in the scheme cannot guarantee the control of the target temperature, and the target life will be very short. In addition, the antenna of the high frequency ion source where the neutrons are generated in this scheme In the outer section of the neutron generator, the high-frequency electromagnetic waves emitted by the antenna will cause strong interference to the power supply and control components of the neutron generator, resulting in unstable operation

3. Chinese patent CN203748097U [authorized announcement date July 3, 2014] announced the scheme of a small directional neutron generator, which is characterized by bombarding a long directional target under the acceleration of a coaxial electric field and generating high flux in the direction of the target axis neutrons, but the lifespan is as short as that of neutron tubes

4. Chinese patent CN203761670U [authorized announcement date August 6, 2014] announced a neutron generator scheme using a grid, which is characterized in that the grid is used to effectively suppress the reverse acceleration of secondary electrons, and the output is not high , short lifespan comparable to that of neutron tubes

5. Chinese patent CN101978429B [authorized announcement date April 29, 2015] announced a long-life and high-efficiency neutron generator. The neutron generator uses a high-frequency coil induction high-frequency ion source, which is characterized by D particles The beam monoatomic ion ratio is high (about 80%), and the efficiency is high, but the inner surface of the quartz glass cavity of the ion source is prone to form a metal film due to ion sputtering, which affects the high-frequency electromagnetic wave feeding into the discharge cavity, and requires regular cleaning and maintenance

There is also a common deficiency in the prior art, that is, the generated neutrons are scattered around the device, causing inconvenience in use, and on the other hand, the energy of the generated neutrons will be attenuated, which is not conducive to its application

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