An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.

An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.

An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.

An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.

An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.

An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.

An ion source having dual indirectly heated cathodes is disclosed. Each of the cathodes may be independently biased relative to its respective filament so as to vary the profile of the beam current that is extracted from the ion source. In certain embodiments, the ion source is used in conjunction with an ion implanter. The ion implanter comprises a beam profiler to measure the current of the ribbon ion beam as a function of beam position. A controller uses this information to independently control the bias voltages of the two indirectly heated cathodes so as to vary the uniformity of the ribbon ion beam. In certain embodiments, the current passing through each filament may also be independently controlled by the controller.

A selectively configurable system for directing an electron beam with a limited energy spread to a sample includes an electron source to generate an electron beam having an energy spread including one or more energies, an aperture having an on-axis opening and an off-axis opening, a first assembly of one or more electron lenses with selectively configurable focal powers positioned to collect the beam from the source and direct the beam to the aperture, a second assembly of one or more selectively configurable electron lenses positioned to collect the beam, a sample stage, and an electron inspection sub-system including electron optics positioned to direct the beam onto one or more samples. The first assembly includes an off-axis electron lens for interacting with the beam at an off-axis position and introducing spatial dispersion to the beam when configured with a nonzero focal power, thus filtering the energy spread.

The present invention provides a technique for constructing compact, high gradient magnetic lenses for charged particle beam focusing. Methods for adjusting the focusing strength of the lenses are provided, based on thermal control, mechanical motion of the magnetic chips within the yoke. The present invention is a method for designing and fabricating permanent magnet focusing elements that are compact, simple to construct, and having a large, adjustable focusing strength. Applications include beamlines for THz radiation sources, free electron lasers, wakefield accelerators and any other charged particle devices that require a compact beamline.

The present invention provides a technique for constructing compact, high gradient magnetic lenses for charged particle beam focusing. Methods for adjusting the focusing strength of the lenses are provided, based on thermal control, mechanical motion of the magnetic chips within the yoke. The present invention is a method for designing and fabricating permanent magnet focusing elements that are compact, simple to construct, and having a large, adjustable focusing strength. Applications include beamlines for THz radiation sources, free electron lasers, wakefield accelerators and any other charged particle devices that require a compact beamline.