A Subnanosecond Pulsed Ion Source for Micrometer Focused Ion Beams
A new, compact design of an ion source delivers nanosecond pulsed ion beams with low emittance, which can be focused to micrometer size. By using a high-power, 25 fs laser pulse focused into a gas region of 10-6 mbar, ions at very low temperatures are produced in the small laser focal volume of 5 μm diameter by 20 μm length through multiphoton ionization. These ions are created in a cold environment, not in a hot plasma, and, since the ionization process itself does not significantly heat them, have as a result essentially room temperature. The generated ion pulse, up to several thousand ions per pulse, is extracted from the source volume with ion optical elements that have been carefully designed by simulation calculations. Externally triggered, its subnanosecond duration and even smaller time jitter allow it to be superimposed with other pulsed particle or laser beams. It therefore can be combined with any type of collision experiment where the size and the time structure of the projectile beam crucially affect the achievable experimental resolution.
C. Hohr et al., "A Subnanosecond Pulsed Ion Source for Micrometer Focused Ion Beams," Review of Scientific Instruments, vol. 79, no. 5, American Institute of Physics (AIP), May 2008.
The definitive version is available at http://dx.doi.org/10.1063/1.2918136
Keywords and Phrases
Focused Ion Beams; Ionization; Micrometers; Multiphoton Processes; Micrometer Focused Ion Beams; Subnanosecond Pulsed Ion Source, Ion Sources
International Standard Serial Number (ISSN)
Article - Journal
© 2008 American Institute of Physics (AIP), All rights reserved.