X-ray source and system comprising an x-ray source

1. An x-ray source configured to provide an omnidirectional transmission of x-ray radiation, the x-ray source comprising:

an anode;

a field emission cathode;

an evacuated chamber transparent to x-ray radiation, the anode and the field emission cathode being arranged inside of the evacuated envelope,

wherein the evacuated envelope is an extended tube shaped evacuated chamber having an essentially circular symmetry, the field emission cathode is arranged adjacently to an inside surface of the extended tube shaped evacuated chamber, and the anode is centrally arranged inside of the extended tube shaped evacuated chamber,

the field emission cathode surrounds the anode,

the field emission cathode comprises a plurality of ZnO nanostructures selected to be at least 1 micrometer,

the field emission cathode is substantially transparent to X-ray radiation and formed as a transmission cathode, and

the x-ray source is connected to a controllable high voltage source, electrons during operation of the x-ray source are accelerated from the field emission cathode in a direction towards the anode, and x-ray radiation is omnidirectionally irradiated from the anode towards and through the field emission cathode and out from the x-ray source.

2. The x-ray source according to claim 1 , wherein the anode has an extended form matching to and extending along at least a portion of the inside of the extended tube shaped evacuated chamber.

3. The x-ray source according to claim 1 , wherein the field emission cathode comprises a plurality of nanostructures.

4. An x-ray system, comprising:

the x-ray source according to claim 1 , and

a controllable high voltage power supply connected to the x-ray source for powering the x-ray source.

5. The x-ray system according to claim 4 , further comprising a control unit for controlling the operation of the power supply.

6. The x-ray system according to claim 4 , further comprising a waterproof arrangement for positioning the x-ray source in an aquatic environment.

7. The x-ray system according to claim 6 , further comprising:

an inlet for receiving a flow of a contaminated liquid; and

an outlet for outputting a flow of the treated liquid,

wherein x-ray radiation is omnidirectionally irradiated towards the flow of the contaminated liquid.

8. The x-ray system according to claim 4 , further comprising

a process air path for receiving a flow of a contaminated air; and

means for arranging the x-ray source within the process air path,

wherein x-ray radiation is omnidirectionally irradiated towards an airflow in the process air path.

9. The x-ray system according to claim 8 , wherein the x-ray source is a component of an electrostatic precipitator, the electrostatic precipitator further comprising at least one collection plate.

10. The x-ray system according to claim 9 , wherein the x-ray system is an air purifier.

11. The x-ray system according to claim 8 , further comprising a filter media for collection of particles, wherein the filter media is arranged upstream of the x-ray source in a direction of the air flow.