189 results about "Plasma channel" patented technology

An electrosurgical device to generate a plasma stream and method to perform endoscopic or laparoscopic surgery within a patient's body comprising an electrosurgical generator coupled to a electrical power source to supply power to the electrosurgical device and a plasma generator including an electrode operatively coupled to the electrosurgical generator to receive electrical energy therefrom and concentrically disposed within an inner noble gas conduit to form a plasma channel coupled to a noble gas source to feed noble gas to the inner noble gas conduit and an outer electronegative gas conduit disposed in surrounding coaxial relation relative to the inner noble gas conduit to cooperatively form an electronegative gas channel therebetween coupled to a gas source to feed electronegative gas to the electronegative gas channel or an outer aspiration conduit disposed in surrounding coaxial relation relative to the inner noble gas conduit to cooperatively form an aspiration channel therebetween coupled to a negative pressure source such that the electrode heats the noble gas to at least partially ionize the noble gas to generate the plasma stream to be directed to the surgical site to perform the surgical procedure while the electronegative gas sustains the plasma stream at the surgical site and dilutes the noble gas adjacent the surgical site or the negative pressure source removes fluid and solid debris from the surgical site respectively.

The present invention relates to a plasma-generating device comprising an anode, a cathode and an elongate plasma channel which extends substantially in the direction from said cathode to said anode. The plasma channel has a throttling portion which is arranged in said plasma channel between said cathode and an outlet opening arranged in said anode. Said throttling portion divides said plasma channel into a high pressure chamber, which is positioned on a side of the throttling portion closest to the cathode, and has a first maximum cross-sectional surface transversely to the longitudinal direction of the plasma channel, and a low pressure chamber, which opens into said anode and has a second maximum cross-sectional surface transversely to the longitudinal direction of the plasma channel, said throttling portion having a third cross-sectional surface transversely to the longitudinal direction of the plasma channel which is smaller than said first maximum cross-sectional surface and said second maximum cross-sectional surface. Moreover at least one intermediate electrode is arranged between said cathode and said throttling portion. The invention also relates to a plasma surgical device, use of such a plasma surgical device in surgery and a method of generating a plasma.

A laser micromachining method is disclosed wherein a workpiece is milled using an incident beam from a laser beam focused above the surface of the workpiece. The incident beam is guided by a plasma channel generated by the incident beam. The plasma channel, which has a relatively constant diameter over an extended distance, is generated by continual Kerr effect self-focusing balanced by ionization of air beam defocusing.

Systems and methods are described for forming continuous laser filaments in transparent materials. A burst of ultrafast laser pulses is focused such that a beam waist is formed external to the material being processed without forming an external plasma channel, while a sufficient energy density is formed within an extended region within the material to support the formation of a continuous filament, without causing optical breakdown within the material. Filaments formed according to this method may exhibit lengths exceeding 10 mm. In some embodiments, an aberrated optical focusing element is employed to produce an external beam waist while producing distributed focusing of the incident beam within the material. Various systems are described that facilitate the formation of filament arrays within transparent substrates for cleaving / singulation and / or marking. Optical monitoring of the filaments may be employed to provide feedback to facilitate active control of the process.

A device and a method for plasma spraying are disclosed. The device comprises, a cathode, an anode, a plasma channel formed by the anode and intermediate electrodes, and one or more flowable material injectors. The plasma channel has a throttling portion that divides the plasma channel into a high pressure portion near the cathode formed by at least one intermediate electrode and a low pressure portion near the anode. During operation, a plasma generating gas is heated by the arc maintained between the cathode and the anode, forming plasma. When the plasma passes through the throttling portion, its speed increases to a supersonic speed, and at the same time its static pressure drops. Flowable materials are injected in the plasma flow in the low pressure portion. The particles in the flowable materials are heated by the plasma and the resultant heated particles and plasma are output from the outlet of the plasma channel.

The present invention relates to a system for detection and identification of airborne biological, chemical and / or nuclear threats such as toxins, spores, bacteria, and viruses in real time at distances from a few meters to several kilometers. Compact femtosecond terawatt laser technology is combined with spectroscopic and mathematical methods for spectral sensing of airborne warfare agents such as bio-aerosols. Trigger sensors and standoff devices based on mobile terawatt femtosecond laser systems are provided that may be placed at strategic monitoring locations. Furthermore, the invention relates to the propagation of airborne ultra-short, ultra-intense laser pulses giving rise to plasma channels (filamentation) producing white light supercontinuum ranging from the ultraviolet (UV), visible (VIS), near infra-red (NIR) and middle infra-red (MIR). According to this invention, the supercontinuum can be directly produced in a particle cloud and hence is uniquely suitable for multi-spectral long-range atmospheric agent and radioactive isotope detection.

A plasma generating apparatus having superior plasma generation efficiency that uses a single reaction chamber. The plasma generating apparatus includes a RF generator for providing a RF power, an antenna for generating an electromagnetic field upon receiving the RF power, a reaction chamber for exciting / ionizing a reaction gas via the electromagnetic field, and generating a plasma, and a plasma channel for absorbing the RF power, and allowing a current signal to be induced to the plasma.

The invention discloses a method for heating oil shale underground in situ. According to the method, shale oil and fuel gas can be obtained from an underground oil shale seam in situ, and the fuel gas can also be obtained from an underground coal seam in situ. Wells are drilled downwardly from the ground surface, and the drilling depth of each well reaches the inside of an operation region of an underground oil shale ore bed. At least two wells are drilled, and electrodes are placed in the wells. Firstly, high-voltage electricity which is sufficient to cause partial discharge of the oil shale ore bed is conducted into the electrodes, and then a plasma channel is formed in the oil shale ore bed and can be subjected to breakdown by the high-voltage electricity; after the resistance of each of two electrode regions is lowered, the two electrodes are used for conducting currents into the plasma channel in the oil shale ore bed; the oil shale ore bed is heated under the resistance heating function of the plasma channel; and released heat is used for realizing thermal cracking and gasification of fixed organic carbon in the oil shale ore bed. Through the method for heating the oil shale underground in situ, the heating speed of an underground ore bed can be increased, hydraulic fracturing does not need to be carried out on a rock stratum, and the use of poisonous conductive materials is avoided at the same time.