Negative ion-based beam injector

Patent metadata

Field	Value
Publication number	US-2021168924-A1
Application number	US-202017104837-A
Country	US
Kind code	A1
Filing date	Nov 25, 2020
Priority date	Mar 8, 2013
Publication date	Jun 3, 2021
Grant date	—

Abstract

A negative ion-based beam injector comprising a negative ion source and an accelerator. The ions produced by the ion source are pre-accelerated before injection into a high energy accelerator by an electrostatic multi-aperture grid pre-accelerator, which is used to extract ion beams from the plasma and accelerate to some fraction of the required beam energy. The beam from the ion source passes through a pair of deflecting magnets, which enable the beam to shift off axis before entering the high energy accelerator. The negative ion-based beam injector can be combined with a neutralizer to produce about a 5 MW neutral beam with energy of about 0.50 to 1.0 MeV. After acceleration to full energy, the beam enters the neutralizer where it is partially converted into a neutral beam. The remaining ion species are separated by a magnet and directed into electrostatic energy converters. The neutral beam passes through a gate valve and enters a plasma chamber.

First claim

What is claimed is:

1 . A negative ion-based beam injector comprising
an ion source adapted to produce a negative ion beam, and an accelerator, wherein the accelerator includes a pre-accelerator and a high energy accelerator, wherein the pre-accelerator is an electrostatic multi aperture grid in the ion source, and wherein the high energy accelerator is spaced apart from the ion source.

2 . The injector of claim 1 , wherein ions from the ion source are pre-accelerated by the pre-accelerator to 120 kV before injection into the high energy accelerator.

3 . The injector of claim 1 , further comprising a pair of deflecting magnets, interposing the pre-accelerator and high energy accelerator, wherein the pair of deflecting magnets enables a beam from the pre-accelerator to shift off axis before entering the high energy accelerator.

4 . The injector of claim 2 wherein the ion source includes a plasma box and plasma drivers.

5 . The injector of claim 4 wherein the internal walls of the plasma box and plasma drivers are maintainable at elevated temperatures of 150-200° C. to prevent cesium accumulation on their surfaces.

6 . The injector of claim 5 wherein the plasma box and drivers include fluid manifolds and passageways to circulate high temperature fluid.

7 . The injector of claim 1 , further comprising a distributing manifold for directly supplying cesium on plasma grids of the accelerator.

8 . The injector of claim 1 , wherein the pre-accelerator includes external magnets to deflect co-extracted electrons in an ion extraction and pre-acceleration regions.

9 . The injector of claim 1 , further comprising a pumping system to pump gas out from a pre-acceleration gap.

10 . The injector of claim 7 wherein the plasma grids are positively biased to repel back streaming positive ions.

11 . The injector of claim 1 , wherein the high energy accelerator is spaced apart from the ion source by a transition zone comprising a low energy beam transport line.

12 . The injector of claim 11 wherein the transition zone includes bending magnets, vacuum pumps and cesium traps.

13 . The injector of claim 12 wherein the bending magnets deflect and focus the beam onto the axis of the high energy accelerator.

14 . The injector of claim 1 , further comprising magnetic lenses following the accelerator to compensate for over focusing in the accelerator and to form a parallel beam.

15 . The injector of claim 1 , wherein the neutralizer includes a plasma neutralizer based on a multi-cusp plasma confinement system with high field permanent magnets at the walls.

16 . The injector of claim 2 wherein the neutralizer includes a photon neutralizer based on a cylindrical cavity with highly reflective walls and pumping with high efficiency lasers.

17 . The injector of claim 1 wherein the neutralizer includes a photon neutralizer based on a cylindrical cavity with highly reflective walls and pumping with high efficiency lasers.

18 . The injector of claim 3 further comprising a residual ion energy recuperator.

19 . The injector of claim 1 further comprising a residual ion energy recuperator.

20 . The injector of claim 2 further comprising a residual ion energy recuperator.

21 . A negative ion-based beam injector comprises
an ion source adapted to produce a negative ion beam, and an accelerator, wherein the accelerator includes a pre-accelerator and a high energy accelerator, wherein the pre-accelerator is in the ion source and the high energy accelerator is spaced apart from the ion source.

22 . A negative ion-based beam injector comprises
an ion source adapted to produce a negative ion beam, wherein the ion source includes a plasma box and plasma drivers, and wherein internal walls of the plasma box and plasma drivers are maintainable at elevated temperatures of 150-200° C. to prevent cesium accumulation on their surfaces, and an accelerator operably coupled to the ion source.

Assignees

• Tae Tech Inc

Inventors

• Belchenko Yuri I
• Burdakov Alexander V
• Davydenko Vladimir I
• Dimov Gennady I
• Ivanov Alexandr A
• Kobets Valeery V
• Smirnov Artem N
• Binderbauer Michl W
• Sevier Donald L
• Richardson Terence E

Classifications

• H05H3/02 Primary

  Molecular or atomic-beam generation, e.g. resonant beam generation · CPC title

• G21K1/00

  Arrangements for handling particles or ionising radiation, e.g. focusing or moderating · CPC title