Abstract: A hull for a planing type watercraft has a front lift surface, a high lift surface, and a back planing surface. The high lift surface is adjacent a rockered keel area and between the front lift surface and the back planing surface. The center of dynamic lift on the high lift surface is at or in front of a point which is 15% of the hull length behind a total center of gravity of the hull under loading. At least the back one third of the high lift surface is cambered, and a beam of the high lift surface is greater than two thirds of the maximum width of the hull. The average camber of the front lift surface, the high lift surface, and the back planing surface together is less than or equal to zero.

Abstract: A hull for a planing type watercraft has a front lift surface, a high lift surface, and a back planing surface. The high lift surface is adjacent a rockered keel area and between the front lift surface and the back planing surface. The center of dynamic lift on the high lift surface is at or in front of a point which is 15% of the hull length behind a total center of gravity of the hull under loading. At least the back one third of the high lift surface is cambered, and a beam of the high lift surface is greater than two thirds of the maximum width of the hull. The average camber of the front lift surface, the high lift surface, and the back planing surface together is less than or equal to zero.

Abstract: High performance of a sailboard is achieved over a wider range of wind and water conditions by providing a hull having two or more planing surfaces which may differ in shape and/or aspect ratio. Drag due to suction at steps between planing surfaces is reduced by venting to the air. Cusp shaping of the respective planing surfaces can reduce and stabilize the angle of attack at the displacement/planing transition without causing fore-and-aft pitching effects known as porpoising.

Abstract: Ion optical methods and apparatus are provided for producing low energy ion beams. The apparatus includes an acceleration electrode for accelerating the ion beam, a deceleration electrode downstream of the acceleration electrode for decelerating the ion beam, and an ion optical element downstream of the deceleration electrode for inhibiting electrons in the beam plasma from reaching the deceleration electrode. The deceleration electrode is biased at a voltage that is selected to provide a potential barrier to thermal ions in the beam plasma to inhibit the thermal ions from reaching the acceleration electrode. The ion optical element maybe implemented as an electron repulsing electrode or as a magnetic element. The acceleration electrode, the deceleration electrode, or both, may be segmented in a direction lateral to the ion beam to define individually controllable electrode segments. The ion optical apparatus may be implemented as an ion source extraction system or as a deceleration lens system.

Abstract: Uniformity of plasma density is enhanced at high plasma density and with reduced gas cracking and/or without electron charging of a workpiece by limiting coupling of voltages to the plasma and returning a majority of RF current to elements of an antenna driven with different phases of a VHF/UHF signal and/or providing a magnetic filter which separates a hot plasma region from a cold plasma region along a side of the chamber and further provides a preferential drift path between the hot and cold plasma regions. The magnetic field structure of the magnetic filter is preferably closed at one end or fully closed to surround the plasma. Additional magnetic elements limit the transverse field at the surface of a workpiece to less than 10 Gauss. Either or both of the antenna and the magnetic filter can be retrofitted to existing plasma reactor vessels and improve the performance and throughput thereof.