Lawrence Livermore National Security, LLC

Opcondys, Inc.

University of California

The United States of America As Represented by the Department of Energy

The United States of America As Represented by the United States

Tpl, Inc.

Stephen E Sampayan

George James Caporaso

Kristin Cortella Sampayan

David M Sanders

John Richardson Harris

Steven Anthony Hawkins

Yu-Jiuan Chen

James S Sullivan

Li-Fang Wang

Christopher M Spadaccini

Vincent L Tang

Steven Falabella

Glenn A Meyer

Gary Guethlein

Brian Rusnak

Hugh C Kirbie

Jeff Morse

Hoang Tan Nguyen

Clifford C Shang

Lars F Voss

Adam M Conway

Rebecca J Nikolic

Mihail Bora

Juan M Elizondo-Decanini

Derek E Decker

Scott D Nelson

Kirk M Slenes

Paulius Vytautas Grivickas

Roger W Werne

Michael L Krogh

Hugh Kirbie

William J Orvis

Sangtae Park

Steven C Davis

James A Watson

Anthony N Payne

Ted F Wieskamp

Arthur C Paul

H M Stoller

Ben Z Rosenblum

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 radiotherapy system includes a particle accelerator configured to receive charged particles from a pulsed source. The particle accelerator includes a pipe configured to allow the charged particles to pass through as a beam, a magnetic core positioned proximate to the pipe and coupled to the pulsed source, and at least one multilayer insulator positioned adjacent to the pipe and the magnetic core. The system also includes a photoconductive switch coupled to the particle accelerator and configured to supply the particle accelerator with a plurality of voltage pulses.

Flash radiotherapy accelerator system

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.

Diffuse discharge circuit breaker

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. The method includes producing a plurality of voltage pulses by the photoconductive switch in response to receiving light incident on the doped crystalline material, and accelerating the charged particles by the particle accelerator based on the plurality of voltage pulses to produce the output radiation beams for flash radiotherapy.

Flash radiotherapy accelerator

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.

Disinfection system with high throughput and low power requirements

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.

Partial discharge suppression in high voltage solid-state devices

A method for producing a neutrons includes producing a voltage of negative polarity of at least &#x2212;100 keV on a surface of a deuterated or tritiated target in response to a temperature change of a pyroelectric crystal of less than about 40&#xb0; C., the pyroelectric crystal having the deuterated or tritiated target coupled thereto, pulsing a deuterium ion source to produce a deuterium ion beam, accelerating the deuterium ion beam to the deuterated or tritiated target, and directing the ion beam onto the deuterated or tritiated target to make neutrons using at least one element of the following: a voltage of the pyroelectric crystal and a high gradient insulator (HGI) surrounding the pyroelectric crystal. The accelerating of the deuterium ion beam is achieved by using an ion accelerating mechanism comprising a pyroelectric stack accelerator having a first thermal altering mechanism for changing a temperature of the pyroelectric stack accelerator.

Neutron generation using pyroelectric crystals

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.

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.

Photoconductive charge trapping apparatus

According to one embodiment, a method for producing a directed neutron beam includes producing a voltage of negative polarity of at least &#x2212;100 keV on a surface of a deuterated or tritiated target in response to a temperature change of a pyroelectric crystal of less than about 40&#xb0; C., the pyroelectric crystal having the deuterated or tritiated target coupled thereto, pulsing a deuterium ion source to produce a deuterium ion beam, accelerating the deuterium ion beam to the deuterated or tritiated target to produce a neutron beam, and directing the ion beam onto the deuterated or tritiated target to make neutrons using at least one of a voltage of the pyroelectric crystal, and a high gradient insulator (HGI) surrounding the pyroelectric crystal. The directionality of the neutron beam is controlled by changing the accelerating voltage of the system. Other methods are presented as well.

A photonic device having wide bandgap (WBG) materials which change electrical behaviors in response to low-intensity light is disclosed. The device comprises an optical waveguide located in an optical path of light to receive the light and to spatially confine the received light as guided light at a higher optical intensity than the received light; a wide bandgap (WBG) material located in an optical path of the guided light output by the optical waveguide; and two electrodes formed at two different locations on the WBG material to provide two electrical contacts of an electrical path within the WBG material, wherein the WBG material exhibits an electrical conductivity that varies with a level of the guided light output by the optical waveguide to turn on or off the electrical path between the two electrodes.

Photoconductive device with optical concentrator

A multi-stage electric voltage converter is disclosed. The converter comprises a voltage source and multiple stages. Each stage of the multiple stages comprises a first and a second and a third switch, and a capacitor, wherein the capacitor is coupled to the voltage source by the first and the second switches and each stage is coupled to a different stage or to an output of the multi-stage electric voltage converter by the third switch so as to allow the capacitor to be charged by the voltage source when the first and the second switches are closed and the third switch is open, and to allow the capacitor to be connected to the output of the multi-stage electric voltage converter when the first and the second switches are open and the third switch is closed.

Bi-directional, transformerless voltage system

Methods, systems, and devices are disclosed for photoconductive switch package configurations. In some aspects, a photoconductive switch package includes of a wide bandgap photoconductive material (e.g., GaN, ZnO, diamond, AlN, SiC, BN, etc.), a source for energetic photons (e.g., a laser), a mechanism to couple the laser into the switch, and a mechanism for high voltage to enter and leave the switch package. In some implementations, the disclosed photoconductive switch packages can be configured as a three terminal device, e.g., similar to transistors, with one of the terminals being laser input or the voltage input to the laser system.

Photoconductive switch package configurations having a profiled resistive element

A photoconductive switch consisting of an optically actuated photoconductive material, e.g. a wide bandgap semiconductor such as SiC, situated between opposing electrodes. The electrodes are created using various methods in order to maximize reliability by reducing resistive heating, current concentrations and filamentation, and heating and ablation due to the light source. This is primarily accomplished by the configuration of the electrical contact geometry, choice of contacts metals, annealing, ion implantation, creation of recesses within the SiC, and the use of coatings to act as encapsulants and anti-reflective layers.

Reliable electrical contacts for high power photoconductive switches

Methods, systems, and devices for high voltage and/or high frequency modulation. In one aspect, an optoelectronic modulation system includes an array of two or more photoconductive switch units each including a wide bandgap photoconductive material coupled between a first electrode and a second electrode, a light source optically coupled to the WBGP material of each photoconductive switch unit via a light path, in which the light path splits into multiple light paths to optically interface with each WBGP material, such that a time delay of emitted light exists along each subsequent split light path, and in which the WBGP material conducts an electrical signal when a light signal is transmitted to the WBGP material, and an output to transmit the electrical signal conducted by each photoconductive switch unit. The time delay of the photons emitted through the light path is substantially equivalent to the time delay of the electrical signal.

High frequency modulation circuits based on photoconductive wide bandgap switches

Growing community of inventors

Manteca, CA, United States of America

Stephen E Sampayan