Spark gap X-ray source

Patent metadata

Field	Value
Publication number	US-9779847-B2
Application number	US-201514739712-A
Country	US
Kind code	B2
Filing date	Jun 15, 2015
Priority date	Jul 23, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

In one embodiment, the invention includes an x-ray source having a cathode with (1) a pointed end or (2) an elongated blade oriented substantially transverse with respect to a longitudinal axis of the cathode. The pointed end or blade can be pointed towards an anode. In another embodiment, the invention includes an x-ray source having a window with an annular-shape, forming a hollow-ring. A convex portion of a half-ball-shape of an anode can extend into a hollow of the annular-shape of the window.

First claim

What is claimed is:

1. An x-ray source comprising:
a. an enclosure including an internal cavity;
b. a gas disposed in the cavity and having a pressure of at least 0.0001 Torr;
c. an anode and a cathode attached to the enclosure;
d. the anode and the cathode being electrically-conductive;
e. the cathode and the anode being spaced apart from each other and electrically insulated from each other;
f. the cathode having a pointed end disposed within the cavity and pointed towards the anode with a gap between the pointed end and the anode; and
g. an electrically-conductive window:
i. associated with and connected to the anode;
ii. being substantially transmissive to x-rays;
iii. forming at least part of a wall of the enclosure; and
iv. separating at least a portion of the cavity from an exterior of the enclosure.

2. The x-ray source of claim 1 , wherein:
a. the cathode is aligned along a longitudinal axis of the enclosure;
b. the window is disposed in a lateral side of the enclosure;
c. the anode includes an inclined region having an acute angle with respect to the longitudinal axis;
d. a target material, configured to emit x-rays in response to impinging electrons from the cathode, is disposed on the inclined region of the anode;
e. the target material is located to receive impinging electrons from the cathode and to emit x-rays towards the window;
f. the inclined region includes a protrusion extending from a face of the anode facing the pointed end of the cathode;
g. a radius of curvature at a distal end of the protrusion is less than 0.5 millimeters; and
h. a distance from the face of the anode to the distal end of the protrusion is greater than two times the radius of curvature.

3. The x-ray source of claim 2 , wherein a diameter of the cathode, at a location where the cathode begins to taper towards the pointed end, is less than 0.75 times the radius of curvature at the distal end of the protrusion.

4. The x-ray source of claim 1 , wherein an internal angle of the pointed end of the cathode is less than 90°.

5. The x-ray source of claim 1 , further comprising:
a. a power supply electrically connected to the anode and the cathode;
b. the power supply configured to provide pulses of voltage between the anode and the cathode having a magnitude sufficiently high to cause periodic arcs between the cathode and the anode; and
c. electrons in the arc, impinging on the anode, cause an emission of x-rays outward from the x-ray source.

6. The x-ray source of claim 1 , wherein the gas comprises at least 85% helium.

7. The x-ray source of claim 1 , wherein:
a. the window includes an annular-shape, forming a ring as one section of the enclosure;
b. the anode includes a half-ball-shape having a convex portion extending into the cavity and into a hollow of the annular-shape; and
c. the convex portion includes a target material configured to emit x-rays in response to impinging electrons from the cathode.

8. The x-ray source of claim 7 , wherein the window comprises carbon fiber composite or graphite.

9. The x-ray source of claim 1 , wherein the window:
a. includes a hollow, bowl-shape, with a concave portion facing the cavity; and
b. the concave portion includes a target material configured to emit x-rays in response to impinging electrons from the cathode.

10. The x-ray source of claim 1 , wherein the x-ray source forms part of a manufacturing system, the system comprising:
a. a table configured for holding a flat panel display during flat panel display manufacturing;
b. a lift pin movably disposed in a hole in the table and the x-ray source is associated with the lift pin and movable with the lift pin;
c. an actuator coupled to the lift pin to displace the lift pin in the hole and to exert a force by the lift pin on the flat panel display to at least assist in lifting the flat panel display off of the table; and
d. the x-ray source configured to emit x-rays between the table and the flat panel display away from the table.

11. The system of claim 10 , wherein:
a. the window includes an annular-shape, forming a ring as one section of the enclosure;
b. the anode includes a half-ball-shape supported by the annular-shape of the window; and
c. the half-ball-shape includes a convex portion extending into the cavity and into a hollow of the annular-shape.

12. A method of using the x-ray source of claim 1 for electrostatic dissipation, the method comprising emitting x-rays outward from the x-ray source into a fluid and ionizing particles in the fluid and using ions in the fluid to reduce a static charge on a component.

13. The method of claim 12 , further comprising:
a. associating the x-ray source with a lift pin, the lift pin configured to apply force against a flat panel display to lift the flat panel display off of a table during manufacture of the flat panel display; and
b. emitting x-rays from the x-ray source between the flat panel display and the table while lifting or holding the flat panel display off of the table and wherein the fluid is air between the flat panel display and the table and the component is the flat panel display.

14. The x-ray source of claim 5 , wherein the power supply is configured to provide the pulses of voltage between the anode and the cathode having a magnitude of between 1 kilovolt and 20 kilovolts.

15. The x-ray source of claim 5 , wherein the power supply is configured to provide the pulses of voltage between the anode and the cathode having a magnitude of between 10 kilovolts and 200 kilovolts.

16. The x-ray source of claim 1 , wherein an internal angle of the pointed end of the cathode is between 60° and 90°.

17. The x-ray source of claim 1 , wherein an internal angle of the pointed end of the cathode is between 30° and 65°.

18. The x-ray source of claim 1 , wherein a diameter of the cathode is less than 0.5 millimeters.

19. An X-ray source comprising:
a. an enclosure including an internal cavity;
b. an anode and a cathode attached to the enclosure;
c. the anode and the cathode being electrically-conductive;
d. the cathode and the anode being spaced apart from each other and electrically insulated from each other;
e. an axis of the enclosure extending from the cathode to a target material disposed on the anode, the target material, configured to emit X-rays in response to impinging electrons from the cathode;
f. a distal free-end of the cathode having an elongated blade oriented substantially traverse with respect to the axis of the enclosure, the blade having a length of at least 20 centimeters;
g. the elongated blade disposed within the cavity and directed towards the anode with a gap between the blade and the anode;
h. an electrically-conductive window:
i. associated with and connected to the anode;
ii. being substantially transmissive to X-rays;
iii. forming at least part of a wall of the enclosure;
iv. separating at least a portion of the cavity from an exterior of the enclosure and

i. a power supply electrically connected to the anode and the cathode;
j. the power supply configured to provide pulses of voltage between the anode and the cathode having a magnitude sufficiently high to cause periodic arcs between the cathode and the anode; and
k. electrons in the arc, impinging on the anode, cause an emission of X-rays outward from the X-ray source.

Assignees

• Moxtek Inc

Inventors

• Miller Eric
• Hansen Bill

Classifications

• H01J35/06

  Cathodes · CPC title

• H01J2235/087

  Electricity · mapped topic

• H01J35/18 Primary

  Windows · CPC title

• H01J35/08

  Anodes; Anti cathodes · CPC title

• H01J2235/086

  Target geometry · CPC title