Neutron tubes

Abstract

A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium / tritium (or even just a tritium) plasma is generated in the chamber and D or D / T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

Description

RELATED APPLICATIONS [0001] This application claims priority of Provisional Applications Ser. Nos. 60 / 355,576 filed Feb. 6, 2002 and 60 / 356,350 filed Feb. 13, 2002, which are herein incorporated by reference.GOVERNMENT RIGHTS [0002] The United States Government has rights in this invention pursuant to Contract No. DE-AC03-76SF00098 between the United States Department of Energy and the University of California.BACKGROUND OF THE INVENTION [0003] The invention relates generally to neutron tubes, and more specifically to neutron tubes based on plasma ion sources. [0004] Conventional neutron tubes employ a Penning ion source and a single gap extractor. The target is a deuterium or tritium chemical embedded in a molybdenum or tungsten substrate. Neutron yield is limited by the ion source performance and beam size. The production of neutrons is limited by the beam current and power deposition on the target. In the conventional neutron tube, the extraction aperture and the target are limit...

AI Technical Summary

Benefits of technology

"The invention is a small neutron generator that can be implanted in the body for brachytherapy applications. It uses a RF-driven plasma ion source with a quartz chamber and an external RF antenna to generate fast neutrons from a D-D reaction. The targeted tumor size is less than 5 cm in diameter, and the dose delivered to healthy tissue outside the tumor is expected to be less than other approaches. The neutron generator can be designed in different sizes and has a conical or tapered target surface to increase the neutron flux and reduce energy loading. The technical effects of the invention are a small size, low dose to healthy tissue, and high neutron flux."

Problems solved by technology

Neutron yield is limited by the ion source performance and beam size.

The production of neutrons is limited by the beam current and power deposition on the target.

In the conventional neutron tube, the extraction aperture and the target are limited to small areas, and so is the neutron output flux.

The deuterium-on-deuterium (D-D) reaction, with a cross section for production a hundred times lower, has not been able to provide the necessary neutron flux.

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