System and method for generating X-rays

1. An X-ray source comprising:

a waveguide having at least one sidewall and a cavity extending therethrough;

at least one electron emitter positioned on an inner surface of a first sidewall of the waveguide for generating at least one electron beam;

at least one an angled opening extending through a second sidewall, the at least one angled opening forming at least one pathway through the second sidewall, wherein the at least one pathway has two opposed sides;

at least one stationary target positioned on an inner surface of one of the two opposed sides of the at least one pathway, the at least one stationary target receiving the at least one electron beam for generating X-rays; and

a conduit coupled through the at least one sidewall of the waveguide providing microwaves from a microwave generator into the cavity of the waveguide, the microwaves generating an electric field for accelerating the at least one electron beam toward the at least one stationary target;

wherein the second sidewall is opposite the first sidewall; and

wherein the two opposed sides of the at least one pathway each having at least one cooling channel adjacent thereto and extending through the second sidewall.

2. The X-ray source of claim 1 , wherein the at least one stationary target is positioned at an obtuse angle with respect to the at least one incident electron beam.

3. The X-ray source of claim 1 , wherein the at least one stationary target is electrically at the same voltage potential as the at least one electron emitter.

4. The X-ray source of claim 1 , wherein the at least one electron emitter is a field emitter.

5. The X-ray source of claim 4 , wherein the field emitter is a field emitter array that is electrically gated.

6. The X-ray source of claim 1 , wherein the at least one electron emitter is a thermionic emitter.

7. The X-ray source of claim 1 , further comprising a radiation window attached to an outer surface of the second sidewall above the at least one target and covering the at least one pathway.

8. An annular X-ray source assembly comprising:

an annular waveguide having at least one sidewall and a cavity extending therethrough;

a plurality of electron emitters placed on an inner surface of a first sidewall of the annular waveguide for generating electrons that are accelerated through the waveguide cavity;

a plurality of stationary targets placed in a plurality of openings extending through a second sidewall, wherein the second sidewall is opposite the first sidewall, and wherein the plurality of stationary targets and plurality of openings are used to collimate X-rays and create a larger coverage area for an X-ray beam; and

a conduit coupled through the at least one sidewall of the annular waveguide providing microwaves from a microwave generator into the cavity of the annular waveguide, the microwaves generating an electric field for accelerating the electrons toward the plurality of stationary targets.

9. The annular X-ray source of claim 8 , wherein the plurality of stationary targets are positioned at an obtuse angle with respect to the incident electrons.

10. The X-ray source of claim 8 , wherein the plurality of stationary targets are electrically at the same voltage potential as the plurality of electron emitters.

11. The annular X-ray source of claim 8 , wherein the plurality of electron emitters are field emitters.

12. The annular X-ray source of claim 8 , wherein the plurality of electron emitters are thermionic emitters.