公开(公告)号：US20210301798A1

公开(公告)日：2021-09-30

申请号：US17214893

申请日：2021-03-28

Applicant: Mahadevan KRISHNAN

Inventor： Mahadevan KRISHNAN ,  Katherine M. VELAS

IPC: F03H1/00 ,  H05H1/48 ,  B64G1/10 ,  B64G1/40

Abstract: A pulsed metal plasma thruster (MPT) cube has a plurality of thrusters, each having a first cathode electrode and a trigger electrode separated from the first electrode by an insulator sufficient to support an initiation plasma, and a porous anode electrode positioned a separation distance from the face of all of the cathode electrodes. The cathode electrode can be either the inner electrode or the outer electrode. A power supply delivers a high voltage pulse to the trigger electrode with respect to the cathode electrode sufficient to initiate a plasma on the surface of the insulator. The plasma transfers between the anode electrode and cathode electrode of selected thrusters, thereby generating a pulse of thrust.

公开(公告)号：US07679025B1

公开(公告)日：2010-03-16

申请号：US11057040

申请日：2005-02-04

Applicant: Mahadevan Krishnan ,  John R. Thompson

Inventor： Mahadevan Krishnan ,  John R. Thompson

IPC: B23K10/00 ,  H05H1/24

CPC classification number: H05H3/06 ,  G21G4/02 ,  H05G2/003 ,  H05H1/48

Abstract: An apparatus for the formation of a dense plasma focus (DPF) has a center electrode formed about an axis, where the center electrode includes a cylindrical part and a tapered part. An outer electrode is formed about the center electrode, and may be either cylindrical, tapered, or formed from a plurality of individual conductors including a helical conductor arrangement surrounding the tapered region of the center conductor. The taper of the center electrode results in an enhanced azimuthal B field in the final region of the device, resulting in increased plasma velocity prior to the dense plasma focus. Using the outer electrode helical structure an auxiliary axial B field is generated during the final acceleration region of the plasma, which reduces axial modal tearing of the plasma in the final acceleration region.

Abstract translation: 用于形成致密等离子体焦点（DPF）的装置具有围绕轴线形成的中心电极，其中中心电极包括圆柱形部分和锥形部分。 外电极围绕中心电极形成，并且可以是圆柱形的，锥形的或由包括围绕中心导体的锥形区域的螺旋形导体布置的多个单独的导体形成的。 中心电极的锥度导致器件的最终区域中增加的方位角B场，导致等离子体聚焦之前的等离子体速度增加。 使用外部电极螺旋结构，在等离子体的最终加速区域期间产生辅助轴向B场，这降低了最终加速区域中等离子体的轴向模态撕裂。

公开(公告)号：US06818853B1

公开(公告)日：2004-11-16

申请号：US10448638

申请日：2003-05-30

Applicant: Jochen Schein ,  Andrew N. Gerhan ,  Robyn L. Woo ,  Michael Y. Au ,  Mahadevan Krishnan

Inventor： Jochen Schein ,  Andrew N. Gerhan ,  Robyn L. Woo ,  Michael Y. Au ,  Mahadevan Krishnan

IPC: B23K1000

CPC classification number: H05H1/54 ,  F03H1/0012 ,  F03H1/0087

Abstract: An apparatus for producing a vacuum arc plasma source device using a low mass, compact inductive energy storage circuit powered by a low voltage DC supply acts as a vacuum arc plasma thruster. An inductor is charged through a switch, subsequently the switch is opened and a voltage spike of Ldi/dt is produced initiating plasma across a resistive path separating anode and cathode. The plasma is subsequently maintained by energy stored in the inductor. Plasma is produced from cathode material, which allows for any electrically conductive material to be used. A planar structure, a tubular structure, and a coaxial structure allow for consumption of cathode material feed and thereby long lifetime of the thruster for long durations of time.

Abstract translation: 使用由低电压DC电源供电的低质量，紧凑的感应能量存储电路的真空电弧等离子体源装置的制造装置用作真空电弧等离子体推进器。 电感器通过开关充电，随后开关断开，并产生Ldi / dt的电压尖峰，从而在隔离阳极和阴极的电阻路径上引发等离子体。 等离子体随后由存储在电感器中的能量保持。 等离子体由阴极材料制成，其允许使用任何导电材料。 平面结构，管状结构和同轴结构允许阴极材料进料的消耗，从而长时间持续推进器的寿命长。

公开(公告)号：US08399849B1

公开(公告)日：2013-03-19

申请号：US12538138

申请日：2009-08-08

Applicant: Mahadevan Krishnan ,  Mahmud Vahdat Roshan ,  Paul Choon Keat Lee ,  Rajdeep Singh Rawat ,  Stuart Victor Springham

Inventor： Mahadevan Krishnan ,  Mahmud Vahdat Roshan ,  Paul Choon Keat Lee ,  Rajdeep Singh Rawat ,  Stuart Victor Springham

IPC: G01T5/00 ,  G01T1/00

CPC classification number: G01T3/06

Abstract: An activation detector for fast-neutrons has a yttrium target exposed to a neutron source. Fast-neutrons which have energy in excess of 1 MeV (above a threshold energy level) generate gamma rays from a nuclear reaction with the yttrium, the gamma rays having an energy level of 908.96 keV, and the resultant gamma rays are coupled to a scintillator which generates an optical response, the optical response of the scintillator is coupled to a photomultiplier tube which generates an electrical response. The number of counts from the photomultiplier tube provides an accurate indication of the fast-neutron flux, and the detector is exclusively sensitive to fast-neutrons with an energy level over 1 MeV, thereby providing a fast-neutron detector which does not require calibration or the setting of a threshold.

Abstract translation: 用于快中子的激活检测器具有暴露于中子源的钇靶。 具有超过1MeV（高于阈值能级）的能量的快中子产生与钇的核反应的伽马射线，伽马射线具有908.96keV的能级，并且所得到的伽马射线与闪烁体 其产生光学响应，闪烁体的光学响应耦合到产生电响应的光电倍增管。 来自光电倍增管的计数提供了快中子通量的精确指示，检测器对能量水平超过1 MeV的快中子是非常敏感的，从而提供不需要校准的快中子检测器 设置阈值。

公开(公告)号：US07827779B1

公开(公告)日：2010-11-09

申请号：US11900372

申请日：2007-09-10

Applicant: Mahadevan Krishnan ,  Kristi Wilson ,  Kelan Champagne ,  Jason D. Wright ,  Andrew N. Gerhan

Inventor： Mahadevan Krishnan ,  Kristi Wilson ,  Kelan Champagne ,  Jason D. Wright ,  Andrew N. Gerhan

IPC: F03H1/00

CPC classification number: F03H1/0012 ,  F03H1/0037 ,  H01J27/26

Abstract: A Liquid Metal Ion Thruster (LMIT) has a substrate having a plurality of pedestals, one end of the pedestal attached to the substrate, and the opposing end of the pedestal having a tip, the pedestals having grooves and the substrate also having grooves coupled to each other and to a source of liquid metal. An extractor electrode positioned parallel to the substrate and above the pedestal tips provides an electrostatic extraction field sufficient to accelerate ions from the tips of the pedestals through the extractor electrode. A series of focusing electrodes with matching apertures provides a flow of substantially parallel ion trajectories, and an optional negative ion source provides a charge neutralization to prevent space charge spreading of the exiting accelerated ions. The assembly is suitable for providing thrust for a satellite while maintaining high operating efficiencies.

Abstract translation: 一种液体金属离子推进器（LMIT）具有一个具有多个基座的基板，底座的一端连接到该基板上，并且底座的相对端具有尖端，该基座具有凹槽，该基板还具有连接到 彼此和液态金属的来源。 平行于基板并且在基座尖端上方设置的提取器电极提供足以加速离子从基座的尖端通过提取器电极的静电引出场。 具有匹配孔的一系列聚焦电极提供基本上平行的离子轨迹的流动，并且可选的负离子源提供电荷中和以防止离开的加速离子的空间电荷扩展。 该组件适用于为卫星提供推力，同时保持高的运行效率。

公开(公告)号：US20070045248A1

公开(公告)日：2007-03-01

申请号：US11417366

申请日：2006-01-31

Applicant: Jochen Schein ,  Andrew Gerhan ,  Robyn Woo ,  Michael Au ,  Mahadevan Krishnan

Inventor： Jochen Schein ,  Andrew Gerhan ,  Robyn Woo ,  Michael Au ,  Mahadevan Krishnan

IPC: B23K9/00 ,  B23K9/02

CPC classification number: H05H1/54 ,  F03H1/0087

Abstract: An apparatus for producing a vacuum arc plasma source device using a low mass, compact inductive energy storage circuit powered by a low voltage DC supply acts as a vacuum arc plasma thruster. An inductor is charged through a switch, subsequently the switch is opened and a voltage spike of Ldi/dt is produced initiating plasma across a resistive path separating anode and cathode. The plasma is subsequently maintained by energy stored in the inductor. Plasma is produced from cathode material, which allows for any electrically conductive material to be used. A planar structure, a tubular structure, and a coaxial structure allow for consumption of cathode material feed and thereby long lifetime of the thruster for long durations of time.

Abstract translation: 使用由低电压DC电源供电的低质量，紧凑的感应能量存储电路的真空电弧等离子体源装置的制造装置用作真空电弧等离子体推进器。 电感器通过开关充电，随后开关断开，并产生Ldi / dt的电压尖峰，从而在隔离阳极和阴极的电阻路径上引发等离子体。 等离子体随后由存储在电感器中的能量保持。 等离子体由阴极材料制成，其允许使用任何导电材料。 平面结构，管状结构和同轴结构允许阴极材料进料的消耗，从而长时间持续推进器的寿命长。

公开(公告)号：US11480162B1

公开(公告)日：2022-10-25

申请号：US17235911

申请日：2021-04-20

Applicant: Mahadevan Krishnan

Inventor： Mahadevan Krishnan

IPC: F03H1/00

Abstract: A pulsed metal plasma thruster (MPT) cube has a plurality of thrusters, each having a first cathode electrode and a trigger electrode separated from the first electrode by an insulator sufficient to support an initiation plasma, and a porous anode electrode positioned a separation distance from the face of all of the cathode electrodes. The cathode electrode can be either the inner electrode or the outer electrode. A power supply delivers a high voltage pulse to the trigger electrode with respect to the cathode electrode sufficient to initiate a plasma on the surface of the insulator. The plasma transfers between the anode electrode and cathode electrode of selected thrusters, thereby generating a pulse of thrust.

公开(公告)号：US10989179B1

公开(公告)日：2021-04-27

申请号：US15987885

申请日：2018-05-23

Applicant: Mahadevan Krishnan

Inventor： Mahadevan Krishnan ,  Katherine M. Velas

IPC: F03H1/00 ,  H05H1/48 ,  B64G1/10 ,  B64G1/40

Abstract: A pulsed metal plasma thruster (MPT) cube has a plurality of thrusters, each having a first cathode electrode and a trigger electrode separated from the first electrode by an insulator sufficient to support an initiation plasma, and a porous anode electrode positioned a separation distance from the face of all of the cathode electrodes. The cathode electrode can be either the inner electrode or the outer electrode. A power supply delivers a high voltage pulse to the trigger electrode with respect to the cathode electrode sufficient to initiate a plasma on the surface of the insulator. The plasma transfers between the anode electrode and cathode electrode of selected thrusters, thereby generating a pulse of thrust.

公开(公告)号：US09109715B2

公开(公告)日：2015-08-18

申请号：US12245748

申请日：2008-10-05

Applicant: Mahadevan Krishnan

Inventor： Mahadevan Krishnan

IPC: F16K31/02 ,  F16K31/06 ,  B05B1/00 ,  B05B1/14

CPC classification number: F16K31/0658 ,  B05B1/005 ,  B05B1/14

Abstract: A high speed valve has a conductive flyer plate responsive to eddy currents induced by an adjacent coil. The eddy currents generate a repulsive force which opens the valve, and a low-mass flyer plate and spring combined with a resonant plate and spring combination provide a fast opening and closing time for the valve. A nozzle structure directs a supersonic flow of gas into a rectangular array of high-density gas suitable for interaction with a laser beam transverse to the rectangular array of jets for the production of wakefield interaction, leading to very high-energy electrons from the gas jet.

Abstract translation: 高速阀具有响应于相邻线圈感应的涡流的导电翼板。 涡流产生打开阀的排斥力，并且与共振板和弹簧组合的低质量飞盘和弹簧组合为阀提供快速的打开和关闭时间。 喷嘴结构将超音速气流引导成高密度气体的矩形阵列，其适于与横向于矩形阵列阵列的激光束相互作用，用于产生尾流相互作用，导致来自气体射流的非常高能量的电子 。

公开(公告)号：US07053333B1

公开(公告)日：2006-05-30

申请号：US10919424

申请日：2004-08-16

Applicant: Jochen Schein ,  Andrew N. Gerhan ,  Robyn L. Woo ,  Michael Y. Au ,  Mahadevan Krishnan

Inventor： Jochen Schein ,  Andrew N. Gerhan ,  Robyn L. Woo ,  Michael Y. Au ,  Mahadevan Krishnan

IPC: B23K10/00

CPC classification number: H05H1/54 ,  F03H1/0012 ,  F03H1/0087

Abstract: An apparatus for producing a vacuum arc plasma source device using a low mass, compact inductive energy storage circuit powered by a low voltage DC supply acts as a vacuum arc plasma thruster. An inductor is charged through a switch, subsequently the switch is opened and a voltage spike of Ldi/dt is produced initiating plasma across a resistive path separating anode and cathode. The plasma is subsequently maintained by energy stored in the inductor. Plasma is produced from cathode material, which allows for any electrically conductive material to be used. A planar structure, a tubular structure, and a coaxial structure allow for consumption of cathode material feed and thereby long lifetime of the thruster for long durations of time.

Abstract translation: 使用由低电压DC电源供电的低质量，紧凑的感应能量存储电路的真空电弧等离子体源装置的制造装置用作真空电弧等离子体推进器。 电感器通过开关充电，随后开关断开，并产生Ldi / dt的电压尖峰，从而在隔离阳极和阴极的电阻路径上引发等离子体。 等离子体随后由存储在电感器中的能量保持。 等离子体由阴极材料制成，其允许使用任何导电材料。 平面结构，管状结构和同轴结构允许阴极材料进料的消耗，从而长时间持续推进器的寿命长。