Abstract:
La cathode comporte une pastille en hexaborure de lanthane et une résistance chauffante en graphite pyrolitique parcourues par un courant électrique de chauffage. La pastille 10 présente la forma d'une pièce creuse de révolution dans laquelle est engagée, et contre une paroi 10a de laquelle est appliquée, la résistance 14, également de révolution. L'invention s'applique en particulier aux appareils de soudage par bombardement électronique. Figure unique.
Abstract:
There is disclosed a method of controlling an electron gun without causing decreases in brightness of the electron beam if a current-limiting aperture cannot be used. The electron gun (10) has a cathode (11), a Wehnelt electrode (12), a control electrode (13), an anode (14), and a controller (22). The Wehnelt electrode (12) has a first opening in which the tip of the cathode is inserted, and focuses thermal electrons emitted from the tip of the cathode (11). The thermal electrons emitted from the tip of the cathode (11) are caused to pass into a second opening by the control electrode (13). The anode (14) accelerates the thermal electrons emitted from the cathode (11) such that the thermal electrons passed through the second opening pass through a third opening and impinge as an electron beam (B1) on a powdered sample (8). The controller (22) sets the bias voltage and the control voltage based on combination conditions of the bias voltage and control voltage to maintain the brightness of the beam constant.
Abstract:
An annular ceramic washer has inner and outer cylindrical surfaces, first and second annular surfaces, and a winding path thick film resistor located on the inner surface. Metal washers are preferably brazed to the end ring surfaces. The annular ceramic washer is useful in vacuum tube applications in establishing a voltage on a target utilizing the voltage of an electrode coupled to the winding path thick film resistor.
Abstract:
The invention relates to a method of reconditioning a used electron beam accelerator for reuse, comprising receiving an electron beam accelerator that has been disconnected from an electron beam machine housing at another location; opening the electron beam accelerator vacuum chamber; replacing an electron generator; sealing the electron beam accelerator vacuum chamber; evacuating the vacuum chamber through a sealable outlet; sealing the sealable outlet; preconditioning the electron beam accelerator for high voltage operation in an electron beam machine; and storing the electron beam accelerator for later use.
Abstract:
The invention relates to a method of reconditioning a used electron beam accelerator for reuse, comprising receiving an electron beam accelerator that has been disconnected from an electron beam machine housing at another location; opening the electron beam accelerator vacuum chamber; replacing an electron generator; sealing the electron beam accelerator vacuum chamber; evacuating the vacuum chamber through a sealable outlet; sealing the sealable outlet; preconditioning the electron beam accelerator for high voltage operation in an electron beam machine; and storing the electron beam accelerator for later use.