An Electron Beam Ion Trap (EBIT) is a device that produces, traps, and excites very highly charged ions. The ions can either be observed in the trap itself or extracted from the trap for external experiments.
FS-IBT was the home of EBIT-II (originally developed at Lawrence Livermore National Laboratory) from 2000-2010. Our research was focused on single ion implantation to create aligned arrays of qubits in, for example, silicon as a host material.
What is an EBIT?
An Electron Beam Ion Trap, or EBIT, is a device that makes and traps very highly charged ions by means of a high current density electron beam. The EBIT was invented at the Lawrence Livermore National Laboratory by Mort Levine and Ross Marrs. It was an idea based upon the Electron Beam Ion Source (EBIS), a design for an ion source intended for use in atomic physics and as an injector into heavy-ion accelerators. In this country, EBISes have been built at Kansas State, Brookhaven National Laboratory, Cornell University, and (in collaboration with our group) at LBNL.
The EBIT is the only ion source in the world that can create highly charged ions at rest. All other sources of highly charged ions involve accelerators that accelerate the ions to very high energies. EBIT, therefore, allows us to study an otherwise inaccessible domain in which the potential energy of an ion is comparable to its kinetic energy.
How an EBIT Works
An EBIT consists of a high-current-density electron beam (up to 5000 A/cm^2) passing through a series of three drift tubes. Ions are trapped radially by the space charge of the electron beam itself, and axially by voltages applied to the end drift tubes.
The electron beam is magnetically compressed by a high magnetic field from a pair of superconducting Helmholtz coils. The electron beam energy in the trap is determined by the voltage applied to the central drift tube.
As electrons collide with the ions in the beam, they strip off electrons until the energy required to remove the next electron is higher than the beam energy. Our original EBIT is capable of an electron beam energy of about 30 keV, enough to make neonlike uranium (U82+, or a uranium atom with only 10 of the usual 92 electrons). At Lawrence Livermore National Laboraotyr a high-energy EBIT, named Super-EBIT, was built with a floating electron gun, that can achieve an electron beam energy of 200 keV, enough to make bare uranium (U92+, a uranium nucleus with no electrons around it).
The EBIT and part of its supporting infrastructure.
The beamline to transport the highly charged ion to a target chamber.
C. D. Weis, A. Schuh, A. Batra, A. Persaud, I. W. Rangelow, J. Bokor, C. C. Lo, S. Cabrini, E. Sideras-Haddad, G. D. Fuchs, R. Hanson, D. D. Awschalom, T. Schenkel, Single atom doping for quantum device development in diamond and silicon. J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. Process. Meas. Phenom. 26, 2596–2600 (2008).
S. J. Robinson, C. L. Perkins, T.-C. Shen, J. R. Tucker, T. Schenkel, X. W. Wang, T. P. Ma, Low-temperature charge transport in Ga-acceptor nanowires implanted by focused-ion beams. Appl. Phys. Lett. 91, 122105 (2007).
E. Sideras-haddad, T. Schenkel, D. Rebuli, A. Persaud, S. Shrivastava, D. H. Schneider, B. Mwakikunga, Electron emission and defect formation in the interaction of slow, highly charged ions with diamond surfaces. Nucl. Instrum. Methods Phys. Res. B. 256, 464–467 (2007).
A. Batra, C. D. Weis, J. Reijonen, A. Persaud, T. Schenkel, S. Cabrini, C. C. Lo, J. Bokor, Detection of low energy single ion impacts in micron scale transistors at room temperature. Appl. Phys. Lett. 91, 193502 (2007).
F. Allen, A. Persaud, S. Park, A. Minor, M. Sakurai, D. H. Schneider, T. Schenkel, Transport of multiply and highly charged ions through nanoscale apertures in silicon nitride membranes. Nucl. Instrum. Methods Phys. Res. B. 244, 323–326 (2006).
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J. W. McDonald, T. Schenkel, A. V. Hamza, D. H. Schneider, Material dependence of total electron emission yields following slow highly charged ion impact. Nucl. Instrum. Methods Phys. Res. B. 240, 829–833 (2005).
A. Persaud, S. J. Park, J. A. Liddle, I. W. Rangelow, J. Bokor, R. Keller, F. I. Allen, D. H. Schneider, T. Schenkel, in Experimental Aspects of Quantum Computing, H. O. Everitt, Ed. (Springer US, Boston, MA, 2005; https://doi.org/10.1007/0-387-27732-3_15), pp. 233–245.
J. W. McDonald, A. V. Hamza, M. W. Newman, J. P. Holder, D. H. G. Schneider, T. Schenkel, Surface charge compensation for a highly charged ion emission microscope. Ultramicroscopy. 101, 225–229 (2004).
P. B. Grabiec, J. Radojewski, M. Zaborowski, K. Domanski, T. Schenkel, I. W. Rangelow, Batch fabricated scanning near field optical microscope/atomic force microscopy microprobe integrated with piezoresistive cantilever beam with highly reproducible focused ion beam micromachined aperture. J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. Process. Meas. Phenom. 22, 16 (2004).
T. Schenkel, K. J. Wu, Probing nano-environments of peptide molecules on solid surfaces by highly charged ion secondary ion mass spectrometry. Int. J. Mass Spectrom. 229, 47–53 (2003).
T. Schenkel, A. Persaud, A. Kraemer, J. W. McDonald, J. P. Holder, A. V. Hamza, D. H. Schneider, Extraction of highly charged ions from the electron beam ion trap at LBNL for applications in surface analysis and materials science. Rev. Sci. Instrum. 73, 663–666 (2002).
J. W. McDonald, R. W. Bauer, D. H. Schneider, Extraction of highly charged ions (up to 90+) from a high-energy electron-beam ion trap. Rev. Sci. Instrum. 73, 30 (2002).
G. A. Machicoane, T. Schenkel, T. R. Niedermayr, M. W. Newmann, A. V. Hamza, A. V. Barnes, J. W. McDonald, J. A. Tanis, D. H. Schneider, Internal dielectronic excitation in highly charged ions colliding with surfaces. Phys. Rev. A. 65, 042903 (2002).
T. Schenkel, A. Kraemer, K.-N. Leung, A. V. Hamza, J. W. Mcdonald, D. H. Schneider, Highly charged ion-secondary ion mass spectrometry (HCI-SIMS): toward metrology solutions for sub-100-nm technology nodes (SPIE, 2001; http://dx.doi.org/10.1117/12.452558).
T. Schenkel, A. V. Hamza, M. W. Newman, G. Machicoane, J. W. McDonald, D. H. Schneider, K. J. Wu, V. K. Lichtenstein, Transport of Hollow Atoms Through Thin Dielectric Films. Phys. Scr. T92, 208–210 (2001).