Abstract:
Ein direktgeheizte Kathode mit Heizungsregelung in Elektronenstrahlgeräten soll über lange Zeiträume hinweg eine stabilisierte Temperatur(T) aufweisen. Erfindungsgemäß weist eine direktgeheizte Kathode Mittel (RS) zur Leistungsregelung der Kathodenheizung mit Hilfe von Mitteln (MV) zur Steuerung des Heizstromes (I) und der Heizspannung (U) auf. Erfindungsgemäß wird eine direktgeheizte Kathode so betrieben, daß ihre Kathodentemperatur konstant ist.
Abstract:
Sterilization device, in particular for sterilization of packaging material, comprising a first chamber, a barrier element and a connection area. The first chamber is adapted to provide charge carriers for sterilization, and the connection area is connected to a third chamber so that the barrier element forms at least one part of the boundary of a volume in which a first atmosphere exists.
Abstract:
Sterilization apparatus for sterilizing packaging containers, the sterilization apparatus comprising a first carousel for supporting a plurality of sterilization devices, the sterilization devices being adapted to sterilize an interior of the packaging containers by electron beam irradiation, and a transport system for transporting the packaging containers, the transport system comprising a second carousel coaxial with the first carousel, wherein the first carousel comprises a first rotatable shaft and the second carousel comprises a separate second rotatable shaft coaxial with the first rotatable shaft.
Abstract:
A method of controlling operation of an indirectly-heated cathode (IHC) ion source comprises a step of measuring a rate of loss of cathode weight of the IHC ion source that occurs during operation using a first cathode configuration and under a first set of operation conditions. A maximum weight loss for the first cathode configuration is determined, and a cathode lifetime is calculated based upon the rate of cathode weight loss and the maximum weight loss. A further method comprises receiving a minimum source bias power value for operation of a cathode in a first configuration, measuring a rate of decrease in source bias power for a cathode in the first configuration, and calculating a lifetime of the cathode based upon the minimum source bias power and rate of decrease in source bias power.
Abstract:
An electron beam apparatus is provided for reliably measuring a potential contrast and the like at a high throughput in a simple structure. The electron beam apparatus for irradiating a sample, such as a wafer, formed with a pattern with an electron beam to evaluate the sample comprises an electron-optical column for accommodating an electron beam source, an objective lens, an E×B separator, and a secondary electron beam detector; a stage for holding the sample, and relatively moving the sample with respect to the electron-optical column; a working chamber for accommodating the stage and capable of controlling the interior thereof in a vacuum atmosphere; a loader for supplying a sample to the stage; a voltage applying mechanism for applying a voltage to the sample, and capable of applying at least two voltages to a lower electrode of the objective lens; and an alignment mechanism for measuring a direction in which dies are arranged on the sample. When the sample is evaluated, a direction in which the stage is moved is corrected to align with the direction in which the dies are arranged.
Abstract:
An arrangement for the regulation of the electron beam power of an electron gun, which comprises a filament cathode, a block cathode and an anode. Between the filament cathode and the block cathode is applied a first voltage, while between the block cathode and the anode a second voltage is applied. With the aid of a first closed-loop regulated system the filament cathode is regulated to a constant current value, which has a filament temperature sufficient for the maximum beam power of the block cathode. A second closed-loop regulated system, such including a block power regulator, which is acted upon by the difference between instantaneous block power value and nominal block power value, regulates the voltage between the filament cathode and the block cathode.
Abstract:
An emitter for a charged particle beam apparatus is provided, said emitter comprising a filament extending between and being attached to first and second supports, an emitter tip attached to the filament, and a stabilization element attached to a third support and to the filament, wherein the first, second and third supports define a triangle so that the stabilization element extends at least partially in a direction perpendicular to the direction in which the filament extends.
Abstract:
An automatic control servo system having a number of cascaded loops equal in number to the number of voltage sources applied to elements of a high-emittance electron source provides accurate and stable electron emission current control independently of beam energy and accommodates large differences in thermal mass between the elements of the electron source, as may be encountered in high-emittance, indirectly heated cathode electron sources. Individual loops of the system may be critically tuned independently of each other.
Abstract:
A method of extending the lifetime of an electron beam filament, typically LaB.sub.6 by applying power to the filament over a preselected period in a substantially linear manner. The time period is typically 20 minutes before a steady state power level is attained with a fully stabilized instrument. Power-down is a reverse of the power-up sequence until all power is removed.
Abstract:
In an electron beam machine for e.g. beam welding, the beam current I.sub.em is stabilized by negative feedback applied to the grid of the electron gun. The optimum cathode heating current is ascertained by causing the cathode heating current I.sub.H to decrease steadily from a maximum value. The beam current is kept constant by the feedback, which adjusts the grid voltage U.sub.W to offset the decrease in cathode temperature caused by the decreasing heating current; the rate of change of the grid voltage U.sub.W is monitored, and when this rate of change exceeds a threshold, the decrease in heating current is arrested, and the heating current is maintained at the thus established optimal value or preferably set at a slightly higher value, which secures an extended length of life of the cathode. This setting of the cathode heating current is repeated after a predetermined interval of time to establish a new value in response to a change of the condition of the cathode.