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Electron beam ion trap

January 01, 1970

Electron beam ion trap (EBIT) is an electromagnetic bottle that produces and confines highly charged ions. An EBIT uses an electron beam focused with a powerful magnetic field to ionize atoms to high charge states by successive electron impact.

Schematics of an electron beam ion trap. Red: electron source filament, blue: electron beam, black: electrodes, green: magnet. The thin line represents the electric potential along the axis.

It was invented by M. Levine and R. Marrs at LLNL and LBNL.[1]

Operation edit

The positive ions produced in the region where the atoms intercept the electron beam are tightly confined in their motion by the strong attraction exerted by the negative charge of the electron beam. Therefore, they orbit around the electron beam, crossing it frequently and giving rise to further collisions and ionization. To restrict the ion motion along the direction of the electron beam axis, trapping electrodes carrying positive voltages with respect to a central electrode are used.

The resulting ion trap can hold ions for many seconds and minutes, and conditions for reaching the highest charge states, up to bare uranium (U92+) can be achieved in this way.[2]

The strong charge needed for radial confinement of the ions requires large electron beam currents of tens up to hundreds of milliampere. At the same time, high voltages (up to 200 kilovolts) are used for accelerating the electrons in order to achieve high charge states of the ions.

To avoid charge reduction of ions by collisions with neutral atoms from which they can capture electrons, the vacuum in the apparatus is usually maintained at UHV levels, with typical pressure values of only 10−12 torr, (~10−10 pascal).

Applications edit

EBITs are used to investigate the fundamental properties of highly charged ions e. g. by photon spectroscopy in particular in the context of relativistic atomic structure theory and quantum electrodynamics (QED). Their suitability to prepare and reproduce in a microscopic volume the conditions of high temperature astrophysical plasmas and magnetic confinement fusion plasmas make them very appropriate research tools. Other fields include the study of their interactions with surfaces and possible applications to microlithography.

References edit

  1. ^ Levine, Morton A; Marrs, R E; Henderson, J R; Knapp, D A; Schneider, Marilyn B (1 December 1987). "The Electron Beam Ion Trap: A New Instrument for Atomic Physics Measurements". Physica Scripta. T22. IOP Publishing: 157–163. doi:10.1088/0031-8949/1988/t22/024. ISSN 0031-8949. S2CID 250767218.
  2. ^ Marrs, R. E.; Elliott, S. R.; Knapp, D. A. (27 June 1994). "Production and Trapping of Hydrogenlike and Bare Uranium Ions in an Electron Beam Ion Trap". Physical Review Letters. 72 (26). American Physical Society (APS): 4082–4085. Bibcode:1994PhRvL..72.4082M. doi:10.1103/physrevlett.72.4082. ISSN 0031-9007. PMID 10056377.
  • Marrs, Roscoe E.; Beiersdorfer, Peter; Schneider, Dieter (1994). "The Electron-Beam Ion Trap". Physics Today. 47 (10). AIP Publishing: 27–34. Bibcode:1994PhT....47j..27M. doi:10.1063/1.881419. ISSN 0031-9228.
  • Marrs, R. E.; Levine, M. A.; Knapp, D. A.; Henderson, J. R. (25 April 1988). "Measurement of electron-impact–excitation cross sections for very highly charged ions". Physical Review Letters. 60 (17). American Physical Society (APS): 1715–1718. Bibcode:1988PhRvL..60.1715M. doi:10.1103/physrevlett.60.1715. ISSN 0031-9007. PMID 10038121. – First EBIT atomic spectroscopy measurement
  • Morgan, C. A.; Serpa, F. G.; Takács, E.; Meyer, E. S.; Gillaspy, J. D.; Sugar, J.; Roberts, J. R.; Brown, C. M.; Feldman, U. (6 March 1995). "Observation of Visible and uv Magnetic Dipole Transitions in Highly Charged Xenon and Barium". Physical Review Letters. 74 (10). American Physical Society (APS): 1716–1719. Bibcode:1995PhRvL..74.1716M. doi:10.1103/physrevlett.74.1716. hdl:1969.1/182526. ISSN 0031-9007. PMID 10057739.
  • Cheng, Hai-Ping; Gillaspy, J. D. (15 January 1997). "Nanoscale modification of silicon surfaces via Coulomb explosion". Physical Review B. 55 (4). American Physical Society (APS): 2628–2636. Bibcode:1997PhRvB..55.2628C. doi:10.1103/physrevb.55.2628. ISSN 0163-1829. S2CID 38152493.
  • Gillaspy, J. D.; Parks, D.C.; Ratliff, L.P. (1998). "Masked ion beam lithography with highly charged ions". Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures. 16 (6). American Vacuum Society: 3294. Bibcode:1998JVSTB..16.3294G. doi:10.1116/1.590367. ISSN 0734-211X.
  • Currell, Frederick John; Asada, Junji; Ishii, Koichi; Minoh, Arimichi; Motohashi, Kenji; et al. (15 October 1996). "A New Versatile Electron-Beam Ion Trap". Journal of the Physical Society of Japan. 65 (10). Physical Society of Japan: 3186–3192. Bibcode:1996JPSJ...65.3186C. doi:10.1143/jpsj.65.3186. ISSN 0031-9015.
  • Beyer, Heinrich F.; Kluge, H.-Jürgen; Shevelko, Viatcheslav P. (1997). X-Ray Radiation of Highly Charged Ions. Spring Series on Atoms+Plasmas. Vol. 19. Berlin, Heidelberg: Springer Berlin Heidelberg. doi:10.1007/978-3-662-03495-8. ISBN 978-3-642-08323-5.

External links edit

  • "EBIT". National Institute of Standards and Technology. 7 December 2010. Retrieved 26 November 2012.
  • "Electron Beam Ion Trap (EBIT)". Lawrence Livermore National Laboratory. 14 April 2009. Retrieved 26 November 2012.
  • "Other EBITs Around the Globe". National Institute of Standards and Technology. 14 December 2011. Retrieved 26 November 2012.

January 01, 1970
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This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations July 2014 Learn how and when to remove this message Electron beam ion trap EBIT is an electromagnetic bottle that produces and confines highly charged ions An EBIT uses an electron beam focused with a powerful magnetic field to ionize atoms to high charge states by successive electron impact Schematics of an electron beam ion trap Red electron source filament blue electron beam black electrodes green magnet The thin line represents the electric potential along the axis It was invented by M Levine and R Marrs at LLNL and LBNL 1 Contents 1 Operation 2 Applications 3 References 4 External linksOperation editThe positive ions produced in the region where the atoms intercept the electron beam are tightly confined in their motion by the strong attraction exerted by the negative charge of the electron beam Therefore they orbit around the electron beam crossing it frequently and giving rise to further collisions and ionization To restrict the ion motion along the direction of the electron beam axis trapping electrodes carrying positive voltages with respect to a central electrode are used The resulting ion trap can hold ions for many seconds and minutes and conditions for reaching the highest charge states up to bare uranium U92 can be achieved in this way 2 The strong charge needed for radial confinement of the ions requires large electron beam currents of tens up to hundreds of milliampere At the same time high voltages up to 200 kilovolts are used for accelerating the electrons in order to achieve high charge states of the ions To avoid charge reduction of ions by collisions with neutral atoms from which they can capture electrons the vacuum in the apparatus is usually maintained at UHV levels with typical pressure values of only 10 12 torr 10 10 pascal Applications editEBITs are used to investigate the fundamental properties of highly charged ions e g by photon spectroscopy in particular in the context of relativistic atomic structure theory and quantum electrodynamics QED Their suitability to prepare and reproduce in a microscopic volume the conditions of high temperature astrophysical plasmas and magnetic confinement fusion plasmas make them very appropriate research tools Other fields include the study of their interactions with surfaces and possible applications to microlithography References edit Levine Morton A Marrs R E Henderson J R Knapp D A Schneider Marilyn B 1 December 1987 The Electron Beam Ion Trap A New Instrument for Atomic Physics Measurements Physica Scripta T22 IOP Publishing 157 163 doi 10 1088 0031 8949 1988 t22 024 ISSN 0031 8949 S2CID 250767218 Marrs R E Elliott S R Knapp D A 27 June 1994 Production and Trapping of Hydrogenlike and Bare Uranium Ions in an Electron Beam Ion Trap Physical Review Letters 72 26 American Physical Society APS 4082 4085 Bibcode 1994PhRvL 72 4082M doi 10 1103 physrevlett 72 4082 ISSN 0031 9007 PMID 10056377 Marrs Roscoe E Beiersdorfer Peter Schneider Dieter 1994 The Electron Beam Ion Trap Physics Today 47 10 AIP Publishing 27 34 Bibcode 1994PhT 47j 27M doi 10 1063 1 881419 ISSN 0031 9228 Marrs R E Levine M A Knapp D A Henderson J R 25 April 1988 Measurement of electron impact excitation cross sections for very highly charged ions Physical Review Letters 60 17 American Physical Society APS 1715 1718 Bibcode 1988PhRvL 60 1715M doi 10 1103 physrevlett 60 1715 ISSN 0031 9007 PMID 10038121 First EBIT atomic spectroscopy measurement Morgan C A Serpa F G Takacs E Meyer E S Gillaspy J D Sugar J Roberts J R Brown C M Feldman U 6 March 1995 Observation of Visible and uv Magnetic Dipole Transitions in Highly Charged Xenon and Barium Physical Review Letters 74 10 American Physical Society APS 1716 1719 Bibcode 1995PhRvL 74 1716M doi 10 1103 physrevlett 74 1716 hdl 1969 1 182526 ISSN 0031 9007 PMID 10057739 Cheng Hai Ping Gillaspy J D 15 January 1997 Nanoscale modification of silicon surfaces via Coulomb explosion Physical Review B 55 4 American Physical Society APS 2628 2636 Bibcode 1997PhRvB 55 2628C doi 10 1103 physrevb 55 2628 ISSN 0163 1829 S2CID 38152493 Gillaspy J D Parks D C Ratliff L P 1998 Masked ion beam lithography with highly charged ions Journal of Vacuum Science amp Technology B Microelectronics and Nanometer Structures 16 6 American Vacuum Society 3294 Bibcode 1998JVSTB 16 3294G doi 10 1116 1 590367 ISSN 0734 211X Currell Frederick John Asada Junji Ishii Koichi Minoh Arimichi Motohashi Kenji et al 15 October 1996 A New Versatile Electron Beam Ion Trap Journal of the Physical Society of Japan 65 10 Physical Society of Japan 3186 3192 Bibcode 1996JPSJ 65 3186C doi 10 1143 jpsj 65 3186 ISSN 0031 9015 Beyer Heinrich F Kluge H Jurgen Shevelko Viatcheslav P 1997 X Ray Radiation of Highly Charged Ions Spring Series on Atoms Plasmas Vol 19 Berlin Heidelberg Springer Berlin Heidelberg doi 10 1007 978 3 662 03495 8 ISBN 978 3 642 08323 5 External links edit EBIT National Institute of Standards and Technology 7 December 2010 Retrieved 26 November 2012 Electron Beam Ion Trap EBIT Lawrence Livermore National Laboratory 14 April 2009 Retrieved 26 November 2012 Other EBITs Around the Globe National Institute of Standards and Technology 14 December 2011 Retrieved 26 November 2012 Retrieved from https en wikipedia org w index php title Electron beam ion trap amp oldid 1223438577, wikipedia, wiki, book, books, library,

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