Abstract: A plasma focus system for neutron production is disclosed that includes an electrode assembly having an inner electrode extending along a pinch axis from a discharge end to a focus end, and an outer electrode surrounding the inner electrode to define a plasma channel for receiving a gas containing neutronic fusion fuel. The system also includes a power supply unit for applying a discharge driving signal to the electrodes, which causes the gas to be ionized into a plasma current sheath at the discharge end that flows along the plasma channel to reach the focus end where the sheath collapses toward the pinch axis to form a plasma pinch that generates fusion neutrons. The inner electrode has a tapered tip at the focus end that is configured to increase a speed of the sheath sufficiently to reach a pinch temperature at which the fusion neutrons are predominantly of thermonuclear origin.

Abstract: A plasma focus system for aneutronic fusion is disclosed that includes an electrode assembly having an inner electrode extending along a pinch axis from a discharge end to a focus end, and an outer electrode surrounding the inner electrode to define a plasma channel for receiving a process gas containing aneutronic fusion fuel. The system also includes a power supply unit for applying a discharge driving signal to the electrodes, which causes the gas to be ionized into a plasma current sheath at the discharge end that flows along the plasma channel to reach the focus end where the sheath collapses toward the pinch axis to form a plasma pinch. The inner electrode has a tapered tip at the focus end that is configured to increase a speed of the sheath sufficiently to reach a pinch temperature high enough for the fuel to undergo aneutronic fusion reactions within the pinch.

Abstract: A plasma focus system for neutron production is disclosed that includes a plasma focus device and a neutron source. The plasma focus device is configured to emit a remnant ion beam. The neutron source includes an enclosure having a cavity formed therein for receiving a target medium. Depending on the application, the target medium can be a gas, a liquid, or a solid. The enclosure includes a beam entrance port configured to allow at least part of the remnant ion beam to enter and travel inside the cavity. As the remnant ion beam travels along the cavity, the beam ions interact with the target medium and undergo both fusion collisions and non-fusion collisions. The fusion collisions produce neutrons and reduce a number of the beam ions, while the non-fusion collisions reduce an energy of the beam ions. A plasma focus method of neutron production is also disclosed.

Abstract: Multilayer film stacks and gray scale processing methods are employed for fabricating phase-shifting masks (PSMs) utilized in lithography. Desired optical transmission and phase-shifting functions of the mask are achieved by controlling the optical properties and thickness of constituent film layers. The mask can be tuned for optimal performance at various wavelengths to an extent beyond that obtainable using a single layer film to control both attenuation and phase shifting of incident light. The processing methods exploit multi-level electron beam or optical beam lithography techniques, and the etch selectivity afforded by selection of appropriate materials for the film stack, to obtain improved yields and reduced processing costs for fabrication of PSMs. In particular, diamond-like carbon (DLC) materials formed by ion beam deposition and having a stress of 1 GPa or less are utilized as etch stop layers.