Abstract: Devices, methods and techniques are disclosed to interrupt a fault current in a high-voltage direct-current circuit. In one example aspect, a device includes a mechanical switch including a pair of contacts configured to be positioned apart upon activation of the circuit breaker, and a photoconductive component connected in parallel with the mechanical switch. The photoconductive component is configured to establish a current upon activation of the circuit breaker. The photoconductive component comprises a crystalline material positioned to receive a pulsed light signal from a laser light source, and a pair of electrodes coupled to the crystalline material and configured to allow an electric field to be established across the crystalline material to generate the current.

Abstract: Methods, devices and systems for ultra-high dose radiotherapy are described that rely in-part on active switching control of a photoconductive switch when the accelerator is accelerating charged particles to produce output radiation at desired dose rates. One example method for producing output radiation in a flash radiotherapy system includes receiving, at a particle accelerator, a charged particle beam, where the particle accelerator system also includes a photoconductive switch coupled to the particle accelerator. The photoconductive switch can operate in a linear mode and includes a doped crystalline material that receives a voltage to establish an electric field across the crystalline material.

Abstract: Devices, methods and techniques are disclosed to perform high confidence sterilization of indoor air with low power requirements. In one example aspect, a sterilization device includes a power source, an energy storage coupled to the power source and configured to store electric charges, a set of electrodes arranged in a specified geometry to have a fixed characteristic impedance, and a switch positioned between the energy storage and the set of electrodes. The switch is configured to operate to establish a pulsed electric field on the set of electrodes.

Abstract: Devices, methods and techniques are disclosed to suppress electrical discharge and breakdown in insulating or encapsulation material(s) applied to solid-state devices. In one example aspect, a multi-layer encapsulation film includes a first layer of a first dielectric material and a second layer of a second dielectric material. An interface between the first layer and the second layer is configured to include molecular bonds to prevent charge carriers from crossing between the first layer and the second layer. The multi-layer encapsulation configuration is structured to allow an electrical contact and a substrate of the solid-state device to be at least partially surrounded by the multi-layer encapsulation configuration.

Abstract: Methods, devices and systems for ultra-high dose radiotherapy are disclosed. The described techniques rely in-part on active switching control of a photoconductive switch during the time the accelerator is accelerating charged particles to produce the output radiation at the desired dose rates. One flash radiotherapy system includes an induction accelerator, and a controllable switch coupled to the induction accelerator. The switch is operable to produce a plurality of voltage pulses to drive the induction accelerator. The radiotherapy system also includes a radiation measurement device to measure output radiation produced by the radiotherapy system and provide feedback to the controllable switch. The controllable switch is operable to, based on the received feedback, modify an amplitude, shape, spacing, number or width of the voltage pulses that are supplied to the particle accelerator to deliver the desired output radiation.

Abstract: Devices, methods and techniques are disclosed to suppress electrical discharge and breakdown in insulating or encapsulation material(s) applied to solid-state devices. In one example aspect, a multi-layer encapsulation film includes a first layer of a first dielectric material and a second layer of a second dielectric material. An interface between the first layer and the second layer is configured to include molecular bonds to prevent charge carriers from crossing between the first layer and the second layer. The multi-layer encapsulation configuration is structured to allow an electrical contact and a substrate of the solid-state device to be at least partially surrounded by the multi-layer encapsulation configuration.

Abstract: Techniques, systems, and devices are disclosed for implementing a photoconductive device performing bulk conduction. In one exemplary aspect, a photoconductive device is disclosed. The device includes a light source configured to emit light; a crystalline material positioned to receive the light from the light source, wherein the crystalline material is doped with a dopant that forms a mid-gap state within a bandgap of the crystalline material to control a recombination time of the crystalline material; a first electrode coupled to the crystalline material to provide a first electrical contact for the crystalline material, and a second electrode coupled to the crystalline material to provide a second electrical contact for the crystalline material, wherein the first and the second electrodes are configured to establish an electric field across the crystalline material, and the crystalline material is configured to exhibit a substantially linear transconductance in response to receiving the light.

Abstract: Techniques, systems, and devices are disclosed for implementing a photoconductive device performing bulk conduction. In one exemplary aspect, a photoconductive device is disclosed. The device includes a light source configured to emit light; a crystalline material positioned to receive the light from the light source, wherein the crystalline material is doped with a dopant that forms a mid-gap state within a bandgap of the crystalline material to control a recombination time of the crystalline material; a first electrode coupled to the crystalline material to provide a first electrical contact for the crystalline material, and a second electrode coupled to the crystalline material to provide a second electrical contact for the crystalline material, wherein the first and the second electrodes are configured to establish an electric field across the crystalline material, and the crystalline material is configured to exhibit a substantially linear transconductance in response to receiving the light.

Abstract: An electron source system utilizing photon enhanced thermionic emission to create a source of well controlled electrons for injection into a series of lenses so that the beam can be fashioned to meet the particular specification for a given use is disclosed. Because of the recent increased understanding and characterization of the bandgap in certain materials, a simplified system can now be realized to overcome the potential barrier at the surface. With this system, only low electric fields with moderate temperatures (˜500 ° C.) are required. The resulting system enables much easier focusing of the electron beam because the random component of the energy of the electrons is much lower than that of a conventional system.

Abstract: An electron source system utilizing photon enhanced thermionic emission to create a source of well controlled electrons for injection into a series of lenses so that the beam can be fashioned to meet the particular specification for a given use is disclosed. Because of the recent increased understanding and characterization of the bandgap in certain materials, a simplified system can now be realized to overcome the potential barrier at the surface. With this system, only low electric fields with moderate temperatures (˜500 ° C.) are required. The resulting system enables much easier focusing of the electron beam because the random component of the energy of the electrons is much lower than that of a conventional system.