Abstract: A method for tracking a variable resonance condition in a plasma coil during creation of plasma from a gas flowing in a plasma torch adjacent to the plasma coil comprises: providing a radio-frequency (RF) power source comprising a power amplifier that generates a radio-frequency power signal with an adjustable operating frequency; providing a high-voltage ignition charge from said RF power source to the gas in plasma torch so as to create an electrical discharge through said gas so as to create a test sample comprising a partial plasma state within said plasma torch; and applying an RF power signal from said plasma coil to said test sample in said plasma torch, wherein said adjustable operating frequency of said power amplifier tracks said variable resonance condition of said plasma coil such that said test sample in the plasma torch achieves a full plasma state.

Abstract: A method for tracking a variable resonance condition in a plasma coil during creation of plasma from a gas flowing in a plasma torch adjacent to the plasma coil comprises: providing a radio-frequency (RF) power source comprising a power amplifier that generates a radio-frequency power signal with an adjustable operating frequency; providing a high-voltage ignition charge from said RF power source to the gas in plasma torch so as to create an electrical discharge through said gas so as to create a test sample comprising a partial plasma state within said plasma torch; and applying an RF power signal from said plasma coil to said test sample in said plasma torch, wherein said adjustable operating frequency of said power amplifier tracks said variable resonance condition of said plasma coil such that said test sample in the plasma torch achieves a full plasma state.

Abstract: A system and method are disclosed for implementing a power source including a power amplifier that generates a radio-frequency power signal with an adjustable operating frequency. The power amplifier also generates a reference phase signal that is derived from the radio-frequency power signal. An impedance match provides the radio-frequency power signal to a plasma coil that has a variable resonance condition. A phase probe is positioned adjacent to the plasma coil to generate a coil phase signal corresponding to the adjustable operating frequency. A phase-locked loop then generates an RF drive signal that is based upon a phase relationship between the reference phase signal and the coil phase signal. The phase-locked loop provides the RF drive signal to the power amplifier to control the adjustable operating frequency, so that the adjustable operating frequency then tracks the variable resonance condition.

Abstract: A system and method are disclosed for implementing a power source including a power amplifier that generates a radio-frequency power signal with an adjustable operating frequency. The power amplifier also generates a reference phase signal that is derived from the radio-frequency power signal. An impedance match provides the radio-frequency power signal to a plasma coil that has a variable resonance condition. A phase probe is positioned adjacent to the plasma coil to generate a coil phase signal corresponding to the adjustable operating frequency. A phase-locked loop then generates an RF drive signal that is based upon a phase relationship between the reference phase signal and the coil phase signal. The phase-locked loop provides the RF drive signal to the power amplifier to control the adjustable operating frequency, so that the adjustable operating frequency then tracks the variable resonance condition.

Abstract: A system and method are disclosed for implementing a power source including a power amplifier that generates a radio-frequency power signal with an adjustable operating frequency. The power amplifier also generates a reference phase signal that is derived from the radio-frequency power signal. An impedance match provides the radio-frequency power signal to a plasma coil that has a variable resonance condition. A phase probe is positioned adjacent to the plasma coil to generate a coil phase signal corresponding to the adjustable operating frequency. A phase-locked loop then generates an RF drive signal that is based upon a phase relationship between the reference phase signal and the coil phase signal. The phase-locked loop provides the RF drive signal to the power amplifier to control the adjustable operating frequency, so that the adjustable operating frequency then tracks the variable resonance condition.

Abstract: A system and method are disclosed for implementing a power source including a power amplifier that generates a radio-frequency power signal with an adjustable operating frequency. The power amplifier also generates a reference phase signal that is derived from the radio-frequency power signal. An impedance match provides the radio-frequency power signal to a plasma coil that has a variable resonance condition. A phase probe is positioned adjacent to the plasma coil to generate a coil phase signal corresponding to the adjustable operating frequency. A phase-locked loop then generates an RF drive signal that is based upon a phase relationship between the reference phase signal and the coil phase signal. The phase-locked loop provides the RF drive signal to the power amplifier to control the adjustable operating frequency, so that the adjustable operating frequency then tracks the variable resonance condition.

Abstract: The method includes the steps of assembling one or more blanks (1) in supporting means (2, 3) so that the or each blank occupies at least the space to be occupied by elongate electrodes and, without disturbing the position of the blanks relative to said supporting means, removing material from all said blanks to generate said electrodes in position in said supporting means. Preferably the material is removed by an electrode-discharge machining (EDM) process, e.g. diesinking. The method avoids time-consuming alignment of preformed electrodes in said supporting means.