Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: This invention improves the stability and control of high-pressure glow discharges by means of a microhllow cathode discharge. The microhollow cathode discharge, which is sustained between two closely spaced electrodes with an opening formed in the electrodes, serves as a plasma cathode for the high-pressure glow. Small variations in the microhollow cathode discharge voltage generate large variations in the microhollow cathode discharge current and consequently in the glow discharge current. In this mode of operation the electrical characteristic of this invention resembles that of a vacuum triode. Using the microhollow cathode discharge as a plasma cathode, stable, dc discharges in argon up to atmospheric pressures can be generated. Additionally, parallel operation of these discharges allows for the generation of large volume plasmas at high gas pressure through superposition of individual glow discharges.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: A method for intracellular electro-manipulation is provided. The method includes applying one or more ultrashort electric field pulse to target cells in a tissue. The ultrashort electric field pulses have sufficient amplitude and duration to modify subcellular structures in the target cells and do not exceed the breakdown field of the medium containing the target cells. The ultrashort electric field pulses can be used to treat a neoplastic condition in a patient by applying one or more ultrashort electric field pulses to at least a portion of a neoplasm in vivo. Such treatments typically involve the application of electric field pulses which have a pulse duration of no more than 1 microsecond and an amplitude of at least 10 kV/cm. An apparatus for destroying target cells in vivo is also provided. The apparatus includes a pulse generator capable of producing one or more ultrashort electric pulse outputs and a delivery system capable of directing the electric pulse output to target cells in vivo.

Abstract: A method for intracellular electro-manipulation is provided. The method includes applying at least one ultrashort electric field pulse to target cells. The ultrashort electric field pulse has sufficient amplitude and duration to modify subcellular structures in the target cells and does not exceed the breakdown field of the medium containing the target cells. The amplitude and duration of the ultrashort electric field pulse are typically insufficient to substantially alter permeability of the surface membranes of the target cells, e.g., by irreversibly disrupting the cell surface membranes. An apparatus for intracellular electro-manipulation is also provided. The apparatus includes a pulse generator capable of producing an ultrashort electric pulse output and a delivery system capable of directing the electric pulse output to target cells.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: A field controlled plasma discharge display element is disclosed for light source use in single element and multiple element plasma discharge electrostatic printers. The display element includes a pair of hollow discharge electric field electrodes, and a third electrode positioned external to and aligned with the discharge electric field electrodes for generating a control electric field proximate to the discharge electric field. The control electric field is used to control the intensity of the plasma discharge by distorting the shape of the generated discharge electric field. The single element plasma discharge device is modulated in accordance with the image to be printed and the modulated output is scanned across the photoconductive surface to produce the latent image.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: A field controlled plasma discharge display element is disclosed for use in single element and multiple element plasma displays. The display element includes a pair of hollow discharge electric field electrodes, and a third electrode positioned external to and aligned with the discharge electric field electrodes for generating a control electric field proximate to the discharge electric field. The control electric field is used to control the intensity of the plasma discharge by distorting the shape of the generated discharge electric field. In a multiple element plasma display using a plurality of the individual display elements of the present invention arrayed in a matrix configuration, a control means is used to control activation and intensity of individual display elements. Individual ones of the elements in the matrix are addressed by a switching circuit including orthogonal control lines in order to instigate a plasma discharge.

Abstract: An electron beam controlled semiconductor switch is capable of carrying large currents without being restricted by the space charge limited current condition. The switch includes a block of semiconductor material having ohmic contacts connectable to first and second electrical conductors. Semi-insulating GaAs may be used as the semiconductor material. A shallow donor or acceptor doped layer may be formed at the surface receiving the electron beam for increased band-edge radiation. This recombination radiation ionizes, together with X-rays produced by Bremsstrahlung, the bulk of the semiconductor block to provide relatively high current density and current gain.

Abstract: An electron beam controlled semiconductor switch is capable of carrying large currents without being restricted by the space charge limited current condition. The switch includes a block of semiconductor material having ohmic contacts connectable to first and second electrical conductors. Semi-insulating GaAs may be used as the semiconductor material. A shallow donor or acceptor doped layer may be formed at the surface receiving the electron beam for increased band-edge radiation. This recombination radiation ionizes, together with X-rays produced by Bremsstrahlung, the bulk of the semiconductor block to provide relatively high current density and current gain.

Abstract: A light activated semiconductor switch is capable of carrying large currents without requiring continuous illumination of the semiconductor to sustain conduction. The switch includes a block of semiconductor material having ohmic contacts connectable to first and second electrical conductors and a deep acceptor level between conduction and valence bands that may be counterdoped with shallow donors. The source of light used to switch between the ON and OFF states is an electromagnetic radiation device which directs first and second beams onto the block between the ohmic contacts. The first beam causes photo-excitation of electrons form the deep acceptor level into the conduction band to provide initial electrons for conduction between the first and second electrical conductors. The second beam causes electrons from the conduction band and holes from the deep acceptor level to combine, thereby interrupting conduction between the first and second electrical conductors.