Low-power, compact piezoelectric particle emission

Patent metadata

Field	Value
Publication number	US-9883576-B2
Application number	US-201414898438-A
Country	US
Kind code	B2
Filing date	Jun 13, 2014
Priority date	Jun 14, 2013
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A low-power, compact piezoelectric particle emitter for emitting particles such as X-rays and neutrons. A piezoelectric transformer crystal receives an input voltage at an input end and generates a higher output voltage at an output electrode disposed at an output end. The emitter is in a vacuum and the output voltage creates an electric field. A charged particle source is positioned relative a target such that charged particles from the charged particle source are accelerated by the electric field toward the target. Interaction between the accelerated charged particles and the target causes one of X-rays and neutrons to be emitted.

First claim

What is claimed is:

1. A low-power, compact piezoelectric neutron generator comprising:
a piezoelectric transformer crystal formed from a piezoelectric material having an input end and an output end;
an output electrode electrically connected to the output end;
a voltage source electrically connected to the input end to apply a first voltage to the crystal and create a second voltage that is higher than the first voltage at the output end caused by the piezoelectric effect, the second voltage creating an electric field generally originating at the output electrode; an ion source configured to produce a plurality of ions, the ions being accelerated as an ion beam by the electric field, the ion beam having an ion beam path; and,
an ion target electrically connected to the output electrode, the ion target being positioned in the ion beam path so that the charged particles interact with the ion target to generate neutrons;
a vacuum chamber containing the piezoelectric transformer crystal, the ion source and the ion target.

2. The neutron generator of claim 1 wherein the ion source comprises a piezoelectric transformer plasma source.

3. The neutron generator of claim 2 wherein the piezoelectric transformer plasma source comprises a piezoelectric transformer configured to generate a high electric field in an aperture and a gas flow supplied to the aperture, the high electric field of the piezoelectric transformer plasma source being configured to cause ionization of gas supplied to the aperture by the gas flow.

4. A low-power, compact emitter of atomic particles comprising:
a piezoelectric transformer crystal formed from a piezoelectric material having an input end and an output end;
an output electrode electrically connected to the output end;
a voltage source electrically connected to the input end to apply a first voltage to the crystal and create a second voltage that is higher than the first voltage at the output end caused by the piezoelectric effect, the second voltage creating an electric field generally at the output electrode;
a charged particle source for emitting charged particles; and,
a target for receiving the charged particles;
a vacuum chamber containing the piezoelectric transformer crystal, the charged particle source and the target;
whereby in operation the electric field accelerates the charged particles toward the target such that the charged particles interact with the target to emit one of neutrons and X-rays.

5. The emitter of claim 4 wherein the piezoelectric transformer crystal has a length, a width, and a height, and the crystal is configured for electric transformation in a length extensional mode.

6. The emitter of claim 5 wherein the piezoelectric transformer crystal has a crystallographic polarization being rotated 45° from vertical about a width-wise axis of the crystal.

7. The emitter of claim 5 wherein the piezoelectric transformer crystal is mounted between brackets at its mid length.

8. The emitter of claim 7 wherein the voltage source is an alternating current voltage source having a frequency equal to about a resonant frequency of the piezoelectric transformer crystal.

9. The emitter of claim 4 wherein the piezoelectric transformer crystal is mounted between brackets at its one-quarter length and other brackets at its three-quarters length.

10. The emitter of claim 9 wherein the voltage source is configured to supply an alternating current voltage having a frequency equal to about two times a resonant frequency of the piezoelectric transformer crystal.

11. The emitter of claim 4 wherein the voltage source is configured to supply an alternating current voltage to the input end of the piezoelectric crystal in an amplitude modulated mode.

12. The emitter of claim 4 wherein the voltage source is configured to supply an alternating current voltage source to the input end of the piezoelectric crystal in a frequency modulated mode.

13. The emitter of claim 4 further comprising an electric field shaper.

14. The emitter of claim 13 wherein the electric field shaper houses a length of the piezoelectric transformer crystal adjacent the output end, the charged particle source, and the target.

15. The emitter of claim 13 wherein the electric field shaper includes a voltage control configured to maintain the electric field shaper at a voltage relative to ground.

16. The emitter of claim 4 wherein the charged particle source is positioned at the output electrode of the piezoelectric transformer crystal and the target is spaced apart therefrom.

17. The emitter of claim 4 wherein the target is positioned at the output electrode of the piezoelectric transformer crystal and the charged particle source is spaced apart therefrom.

18. A low-power, compact piezoelectric X-ray generator comprising:
a piezoelectric transformer crystal formed from a piezoelectric material having an input end and an output end;
an output electrode electrically connected to the output end;
a voltage source electrically connected to the input end to apply a first voltage to the crystal and create a second voltage that is higher than the first voltage at the output end caused by to the piezoelectric effect, the second voltage creating an electric field generally at the output electrode;
an electron emitter configured to emit a beam of electrons accelerated by the electric field;
a bremsstrahlung target positioned in the electron beam so that the electrons interact with the target to generate X-rays;
a vacuum chamber containing the piezoelectric transformer crystal, the electron emitter and the bremsstrahlung target.

19. The X-ray generator of claim 18 wherein the electron emitter comprises a thermionic emitter spaced apart from the output electrode.

20. The X-ray generator of claim 18 wherein the electron emitter comprises a high field electron emitter electrically connected to the output electrode.

Assignees

• Univ Missouri

Inventors

• Kovaleski Scott D
• Gall Brady B
• Benwell Andrew L
• Norgard Peter
• Vangordon James

Classifications

• H01J2235/02

  Electrical arrangements · CPC title

• H05G1/06

  X-ray tube and at least part of the power supply apparatus being mounted within the same housing · CPC title

• H01J35/065

  Field emission, photo emission or secondary emission cathodes · CPC title

• H05H3/06 Primary

  Generating neutron beams (targets for producing nuclear reactions H05H6/00; neutron sources G21G4/02) · CPC title

• H05H2001/2481

  Electricity · mapped topic