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.

In an x-ray source, an isolation circuit can isolate bias voltage at a cathode from a bias voltage at an alternating current source (AC source). The isolation circuit can transfer alternating current from the AC source to the cathode. The isolation circuit can be made repeatedly with minimal variation or failed parts, can be light, and can be small. The isolation circuit can include planar transformer(s). Each planar transformer can include a primary trace on a primary circuit board and a secondary trace on a secondary circuit board. The primary trace and the secondary trace can each include a spiral shape. The primary trace can be located in close proximity to the secondary trace such that alternating electrical current through the primary trace will induce alternating electrical current through the secondary trace.

Some embodiments include an apparatus, comprising: a support substrate; a field emitter device disposed on the support substrate, including a gate and a contact electrically connected to the gate; a conductive plate, including: a protrusion electrically connected to the contact of the field emitter device; and a clamp coupled to the support substrate and the conductive plate such that the conductive plate electrically connects to the contact of the field emitter device.

One or more example embodiments relates to a cathode device and an X-ray source. The cathode device for an X-ray source has an electron emitter including a plurality of field effect emitter elements aligned in parallel to form an emission surface on the upper side of the plurality of field effect emitter elements aligned in parallel a gate electrode, arranged above the emission surface, a multiple first contact elements for at least two independently current-carrying current paths of the electron emitter, electrons from at least one of the current paths are emittable depending on an emission voltage between the gate electrode and the emission surface via the field effect emitter elements; and an emitter seat including multiple second contact elements, the multiple second contact elements connectable with the multiple first contact elements for closing the current paths.

One or more example embodiments relates to a cathode device and an X-ray source. The cathode device for an X-ray source has an electron emitter including a plurality of field effect emitter elements aligned in parallel to form an emission surface on the upper side of the plurality of field effect emitter elements aligned in parallel a gate electrode, arranged above the emission surface, a multiple first contact elements for at least two independently current-carrying current paths of the electron emitter, electrons from at least one of the current paths are emittable depending on an emission voltage between the gate electrode and the emission surface via the field effect emitter elements; and an emitter seat including multiple second contact elements, the multiple second contact elements connectable with the multiple first contact elements for closing the current paths.