Electric dissociation of negative ions - II

M. J. Nadeau; A. E. Litherland; M. A. Garwan; X. L. Zhao

doi:10.1016/0168-583X(94)96017-8

Electric dissociation of negative ions - II

M. J. Nadeau^*, A. E. Litherland, M. A. Garwan, X. L. Zhao

^*Corresponding author for this work

King Fahd University of Petroleum & Minerals

Research output: Contribution to journal › Article › peer-review

27 Scopus citations

Abstract

As an alternative to naturally occurring negative ion discrimination, we have used electric dissociation to discriminate between isobars, by destroying the weaker negative ion of a pair. This technique also permits the determination of the properties of the quantum states and the binding energy of some weakly bound negative ions (Ca, Tm, Dy and Yb), some of which had not been studied previously (Tm, Dy, Yb). During the course of this study, it was also established that some very weakly bound negative ions (Dy and Yb) are destroyed by weak electric fields such as those in tandem accelerators. This fact was used to verify the theory of electric dissociation by the comparison of the dissociation probability under different field configurations and gradients. The results regarding the lanthanide elements indicate that in all three cases the extra electron occupies a p orbital which does not follow the "natural" filling of the periodic table. The study of Ca^- concluded that the lowest states are the 4s²4p ²P J = 1 2 3 2 states with binding energy of 21.0 ± 2.5 meV and a spin-orbit splitting in the range 0.4-.5 meV with a maximum probability at 0.75 meV. The ordering of the levels has not yet been established.

Original language	English
Pages (from-to)	265-269
Number of pages	5
Journal	Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume	92
Issue number	1-4
DOIs	https://doi.org/10.1016/0168-583X(94)96017-8
State	Published - 3 Jun 1994

Bibliographical note

Funding Information:
We wish to thank Dr. L.R. K&us and the staff of the IsoTrace Laboratory for their continued interest and help in this work. The stimuIatingd iscussionsw e have had with Dr. S.H. Vosko and his colleagueso n their extensivet heoreticalw ork on negativei ons were also invaluable. We are very grateful to Drs. H.R. Andrews and V. Koslowski of AECL for their help and collaboration. We also wish to thank Dr. J.C. Ruck-lidge for providings omes ampleso f the elementss tud-ied. This work was supportedi n part by the Natural Sciencesa nd Engineering ResearchC ouncil of Canada and the Kingdom of Saudi Arabia.

ASJC Scopus subject areas

Nuclear and High Energy Physics
Instrumentation

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10.1016/0168-583X(94)96017-8

Cite this

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title = "Electric dissociation of negative ions - II",

abstract = "As an alternative to naturally occurring negative ion discrimination, we have used electric dissociation to discriminate between isobars, by destroying the weaker negative ion of a pair. This technique also permits the determination of the properties of the quantum states and the binding energy of some weakly bound negative ions (Ca, Tm, Dy and Yb), some of which had not been studied previously (Tm, Dy, Yb). During the course of this study, it was also established that some very weakly bound negative ions (Dy and Yb) are destroyed by weak electric fields such as those in tandem accelerators. This fact was used to verify the theory of electric dissociation by the comparison of the dissociation probability under different field configurations and gradients. The results regarding the lanthanide elements indicate that in all three cases the extra electron occupies a p orbital which does not follow the {"}natural{"} filling of the periodic table. The study of Ca- concluded that the lowest states are the 4s24p 2P J = 1 2 3 2 states with binding energy of 21.0 ± 2.5 meV and a spin-orbit splitting in the range 0.4-.5 meV with a maximum probability at 0.75 meV. The ordering of the levels has not yet been established.",

author = "Nadeau, \{M. J.\} and Litherland, \{A. E.\} and Garwan, \{M. A.\} and Zhao, \{X. L.\}",

note = "Funding Information: We wish to thank Dr. L.R. K\&us and the staff of the IsoTrace Laboratory for their continued interest and help in this work. The stimuIatingd iscussionsw e have had with Dr. S.H. Vosko and his colleagueso n their extensivet heoreticalw ork on negativei ons were also invaluable. We are very grateful to Drs. H.R. Andrews and V. Koslowski of AECL for their help and collaboration. We also wish to thank Dr. J.C. Ruck-lidge for providings omes ampleso f the elementss tud-ied. This work was supportedi n part by the Natural Sciencesa nd Engineering ResearchC ouncil of Canada and the Kingdom of Saudi Arabia.",

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doi = "10.1016/0168-583X(94)96017-8",

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AU - Nadeau, M. J.

AU - Litherland, A. E.

AU - Garwan, M. A.

AU - Zhao, X. L.

N1 - Funding Information: We wish to thank Dr. L.R. K&us and the staff of the IsoTrace Laboratory for their continued interest and help in this work. The stimuIatingd iscussionsw e have had with Dr. S.H. Vosko and his colleagueso n their extensivet heoreticalw ork on negativei ons were also invaluable. We are very grateful to Drs. H.R. Andrews and V. Koslowski of AECL for their help and collaboration. We also wish to thank Dr. J.C. Ruck-lidge for providings omes ampleso f the elementss tud-ied. This work was supportedi n part by the Natural Sciencesa nd Engineering ResearchC ouncil of Canada and the Kingdom of Saudi Arabia.

PY - 1994/6/3

Y1 - 1994/6/3

N2 - As an alternative to naturally occurring negative ion discrimination, we have used electric dissociation to discriminate between isobars, by destroying the weaker negative ion of a pair. This technique also permits the determination of the properties of the quantum states and the binding energy of some weakly bound negative ions (Ca, Tm, Dy and Yb), some of which had not been studied previously (Tm, Dy, Yb). During the course of this study, it was also established that some very weakly bound negative ions (Dy and Yb) are destroyed by weak electric fields such as those in tandem accelerators. This fact was used to verify the theory of electric dissociation by the comparison of the dissociation probability under different field configurations and gradients. The results regarding the lanthanide elements indicate that in all three cases the extra electron occupies a p orbital which does not follow the "natural" filling of the periodic table. The study of Ca- concluded that the lowest states are the 4s24p 2P J = 1 2 3 2 states with binding energy of 21.0 ± 2.5 meV and a spin-orbit splitting in the range 0.4-.5 meV with a maximum probability at 0.75 meV. The ordering of the levels has not yet been established.

AB - As an alternative to naturally occurring negative ion discrimination, we have used electric dissociation to discriminate between isobars, by destroying the weaker negative ion of a pair. This technique also permits the determination of the properties of the quantum states and the binding energy of some weakly bound negative ions (Ca, Tm, Dy and Yb), some of which had not been studied previously (Tm, Dy, Yb). During the course of this study, it was also established that some very weakly bound negative ions (Dy and Yb) are destroyed by weak electric fields such as those in tandem accelerators. This fact was used to verify the theory of electric dissociation by the comparison of the dissociation probability under different field configurations and gradients. The results regarding the lanthanide elements indicate that in all three cases the extra electron occupies a p orbital which does not follow the "natural" filling of the periodic table. The study of Ca- concluded that the lowest states are the 4s24p 2P J = 1 2 3 2 states with binding energy of 21.0 ± 2.5 meV and a spin-orbit splitting in the range 0.4-.5 meV with a maximum probability at 0.75 meV. The ordering of the levels has not yet been established.

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ER -

Electric dissociation of negative ions - II

Abstract

Bibliographical note

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