Hostname: page-component-5d59c44645-lfgmx Total loading time: 0 Render date: 2024-02-27T00:57:04.272Z Has data issue: false hasContentIssue false

Ion-pair Ionization in CO2-fed Cesium Sputter Sources

Published online by Cambridge University Press:  27 December 2019

John S Vogel*
University of California (retired); 8300 Feliz Creek Dr., Ukiah, CA 95482, USA
Alexander M Stolz
Institut für Kernphysik; Universität zu Köln; Zülpicher Str. 77, 50937 Köln DE, Germany
*Corresponding author. Email:


A collision-radiation model of the solid sample cesium sputter ion source led to the rediscovery of anion production by ion-pair production. The model revealed physical processes that may produce high current outputs from such sources and suggested new ways of obtaining high outputs at lower heat and conductive stress to the source. Primary among these solutions is the electron excitation of primary Cs0 recycled from the sample to provide states that efficiently create chosen anions. Here we look at how the processes might apply to gas-fed ion sources.

Conference Paper
© 2019 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Selected Papers from the 23rd International Radiocarbon Conference, Trondheim, Norway, 17–22 June, 2018



Andersson, P, Martschini, M, Priller, A, Steier, P, Golser, R, Forstner, O. 2013. Spectroscopic analysis of the blue light emitted from Middleton type cesium sputter negative ion sources. Nuclear Instruments and Methods in Physics Research B 295:5560.CrossRefGoogle Scholar
Avilkina, V, Andrianova, N, Borisov, A, Mashkova, E, Parikis, E. 2011. Energy and temperature dependence of ion-induced electron emission from polycrystaline graphite. Nuclear Instruments and Methods in Physics Research B 269:995998.CrossRefGoogle Scholar
Baede, APM, Moutinho, AMC, De Vries, AE, Los, J. 1969. Total cross sections for charge transfer between alkali atoms and halogen molecules. Chemical Physics Letters 3(7):530531.CrossRefGoogle Scholar
Barbier, L, Djerad, MT, Chéret, M. 1986, Collisional ion-pair formation in an excited alkali-metal vapor. Physical Review A 34(4):2710.10.1103/PhysRevA.34.2710CrossRefGoogle Scholar
Bronk, CR, Hedges, REM. 1987. A gas ion source for radiocarbon dating. Nuclear Instruments and Methods in Physics Research B 29:45.10.1016/0168-583X(87)90201-1CrossRefGoogle Scholar
Buslov, E, Zon, BA. 2012. Formation of negative ions in collisions between Rydberg atoms and neutral particles. Physical Review A:85(4).10.1103/PhysRevA.85.042709CrossRefGoogle Scholar
Carrillo, I, Ramirez, JM, Magaña, LF. 2015. Adsorption of carbon monoxide, carbon dioxide and methane on hexagonal boron nitride with high titanium coverage. Surface Science. 637638:4852.CrossRefGoogle Scholar
Cernusca, S, Fürsatz, M, Winter, HP, Aumayr, F. 2005. Ion-induced kinetic electron emission from HOPG with different surface orientation. Europhysics Letters 70:768.10.1209/epl/i2004-10521-xCrossRefGoogle Scholar
Ciborowski, SM, Liu, G, Graham, JD, Buytendyk, AM, Bowers, KH. 2018. Dipole-bound anions: formed by Rydberg electron transfer (RET) and studied by velocity map imaging–anion photoelectron spectroscopy (VMI–aPES). Eur. Phys. Jour. D 72:139.CrossRefGoogle Scholar
Desfrancois, C. 1995. Determination of electron binding energies of ground-state dipole-bound molecular anions. Physical Review A 51(5):36673675.CrossRefGoogle ScholarPubMed
Dietz, LA, Sheffield, JC. 1975. Secondary electron emission induced by 5–30-keV monatomic ions striking thin oxide films. Journal of Applied Physics 46:4361.CrossRefGoogle Scholar
Fahrni, SM, Wacker, L, Synal, H-A, Szidat, S. 2013. Improving a gas ion source for 14C AMS. Nuclear Instruments and Methods in Physics Research B 294:320327.10.1016/j.nimb.2012.03.037CrossRefGoogle Scholar
Itikawa, Y. 2002. Cross sections for electron collisions with carbon dioxide. J. Phys. Chem. Ref. Data. 31: 749.CrossRefGoogle Scholar
Klein, M, Mous, DJW. 2017. Technical improvements and performance of the HVE AMS sputter ion source SO-110. Nuclear Instruments and Methods in Physics Research B 406:210.CrossRefGoogle Scholar
Klyucharev, A. 1993. Chemi-ionization processes. Physics Uspekhi 36:486.10.1070/PU1993v036n06ABEH002162CrossRefGoogle Scholar
Krebs, KH. 1983. Recent advances in the field of ion-induced kinetic electron emission from solids. Vacuum 33:555.10.1016/0042-207X(83)90050-7CrossRefGoogle Scholar
Kudriatsev, Y, Villegas, A, Godines, A, Asomoza, R. 2005. Calculation of the surface binding energy for ion sputtered particles. Appl. Surf. Sci. 239:273278.10.1016/j.apsusc.2004.06.014CrossRefGoogle Scholar
Lachner, J, Kasberger, M, Martschini, M, Priller, A, Steier, P, Golser, R. 2015. Developments towards detection of 135Cs at VERA. Nuclear Instruments and Methods in Physics Research B 361(C):440444.10.1016/j.nimb.2015.01.032CrossRefGoogle Scholar
Lee, YTT, Mahan, BH. 1965. Photosensitized ionization of alkali-metal vapors. The Journal of Chemical Physics 42(8):28932896.10.1063/1.1703258CrossRefGoogle Scholar
Litherland, AE, Paul, M, Allenc, KW, Gove, HE. 1987. Fundamentals of accelerator mass spectrometry [and Discussion]. Phil. Trans. R. Soc. London A 323:521.CrossRefGoogle Scholar
Middleton, R. 1984. A versatile high intensity negative ion source. Nuclear Instruments and Methods in Physics Research 220:105.10.1016/0167-5087(84)90416-2CrossRefGoogle Scholar
Middleton, R, Klein, J. 1999. Production of metastable negative ions in a cesium sputter source: Verification of the existence of N2 and CO . Physical Review A 60(5):3786.CrossRefGoogle Scholar
Mihajlov, AA, Srećković, VA, Ignjatović, LM, Klyucharev, AN. 2012, The chemi-ionization processes in slow collisions of Rydberg atoms with ground state atoms: mechanism and applications, Journal of Cluster Science 23(1):4775.10.1007/s10876-011-0438-7CrossRefGoogle Scholar
Porezag, D, Frauenheim, T, Köhler, T, Seifert, G, Kaschner, R. 1995. Construction of tight-binding-like potentials on the basis of density-functional theory: Application to carbon. Physical Review B 51(19):12947.CrossRefGoogle Scholar
Priti, D, Gangwar, RK, Srivastava, R. 2017. Calculation of fully relativistic cross sections for electron excitation of cesium atom and its application to the diagnostics of hydrogen-cesium plasma. Journal of Qualitative Spectroscopy and Radiation Transfer 187:426.CrossRefGoogle Scholar
Reicherts, M, Roth, T, Gopalan, A, Ruf, MWW, Hotop, H, Desfrançois, C, Fabrikant, II. 1997. Controlled formation of weakly bound atomic negative ions by electron transfer from state-selected Rydberg atoms. EPL (Europhysics Letters) 40(2):129.CrossRefGoogle Scholar
Ruano, G, Vidal, RA, Ferron, J, Baraguiola, RA. 2011. High energy excitations in ion-induced electron enission from AlF3 . Surface Science 605:18071811.CrossRefGoogle Scholar
Ruff, M, Wacker, L, Gäggler, HW, Suter, M. 2007. A gas ion source for radiocarbon measurements. Radiocarbon 49:307.10.1017/S0033822200042235CrossRefGoogle Scholar
Sigmund, P. 1969, Theory of sputtering. I. Sputtering yield of amorphous and polycrystalline targets. Physical Review 184:383.CrossRefGoogle Scholar
Stein, JD and White, FA. 1972. New method for the measurement of electron yield from ion bombardment. Jour. Applied Physics 43:2617.CrossRefGoogle Scholar
Stolz, A 2020. Einrichtung und Weiterentwicklung eines 14CO2-Systems am 6 MV TANDETRON Beschleuniger des CologneAMS [Ph.D. thesis]. Cologne: University of Cologne. 112 pGoogle Scholar
Stolz, A, Dewald, A, Altenkirch, R, Herb, S, Heinze, S, Schiffer, M, Feuerstein, C, Muller-Gatermann, C, Wotte, A, Rethemeyer, J, Dunai, T. 2017. Radiocarbon measurements of small gaseous samples at Cologne AMS. Nucl. Instr. and Meth. B 406: 283286.CrossRefGoogle Scholar
Stolz, A, Dewald, A, Heinze, S, Altenkirch, R, Hackenberg, G, Herb, S, Muller-Gatermann, C, Schiffer, M, Zitzer, G, Wotte, A, Rethemeyer, J, Dunai, T. 2018. Improvements in the measurement of small 14CO2 samples at Cologne AMS. Nuclear Instruments and Methods in Physics Research B. In press.Google Scholar
Stout, VL, Gibbons, MD. 1955. Gettering of gas by tiyanium. Journal of Applied Physics 26:1488.CrossRefGoogle Scholar
Szmytkowski, C. and Maciqg, K. 1996. Absolute electron-scattering totaI cross section measurements for noble gas atoms and diatomic molecules. Physica Scripta 54: 271280.CrossRefGoogle Scholar
Thomas, LD, Nesbet, RK. 1975. Low energy electron scattering by atomic carbon. Phys. Rev. A 12:23782382.CrossRefGoogle Scholar
Uhl, T, Kretschmer, W, Luppold, W, Scharf, A. 2004. Direct coupling of an elemental analyzer and a hybrid ion source for AMS measurements. Radiocarbon 46:65.CrossRefGoogle Scholar
Uhl, T, Luppold, W, Rottenbach, A, Scharf, A, Kretschmer, W. 2007. Development of an automatic gas handling system for microscale AMS 14C measurements. Nuclear Instruments and Methods in Physics Research B 259:303.10.1016/j.nimb.2007.01.173CrossRefGoogle Scholar
Vandervorst, W, Janssens, T, Huyghebaert, C, Berghmans, B. 2008. The fate of the (reactive) primary ion: Sputtering and desorption. Applied Surface Science 255:12061214.10.1016/j.apsusc.2008.05.089CrossRefGoogle Scholar
Vogel, JS. 2013. Neutral resonant ionization in the high-intensity cesium sputter source. In: Third International Symposium on Negative Ions, Beams and Sources. AIP Conference Series 1515:8998.CrossRefGoogle Scholar
Vogel, JS, Giacomo, JA, Dueker, SR. 2013. Quantifying absolute carbon isotope ratios by AMS. Nuclear Instruments and Methods in Physics Research B 294:340348.CrossRefGoogle Scholar
Vogel, JS. 2015. Anion formation by neutral resonant ionization. Nuclear Instruments and Methods in Physics Research B 361:156–62.CrossRefGoogle Scholar
Vogel, JS. 2016. Anion formation in sputter ion sources by neutral resonant ionization. Review of Scientific Instruments 87:02A504.CrossRefGoogle ScholarPubMed
Vogel, JS, Giacomo, JA. 2016. Increased 14C AMS efficiency from reduced competitive ionization. Radiocarbon. doi: 10.1017/RDC.2016.38.Google Scholar
Vogel, JS. 2018. LASIS: the laser assisted sputter ion source. Nuclear Instruments and Methods in Physics Research B. doi: 10.1016/j.nimb.2018.07.015 Google Scholar
Submitted Vogel-Stolz Manuscript Wünderlich, D, Wimmer, C, Friedl, R. 2014. A collisional radiative model for low-pressure hydrogen–caesium plasmas and its application to an RF source for negative hydrogen ions. Journal of Qualitative Spectroscopy and Radiation Transfer 149:360.CrossRefGoogle Scholar
Xu, S, Dougans, A, Freeman, SPHT, Maden, C, Loger, R. 2007. A gas ion source for radiocarbon measurement at SUERC. Nuclear Instruments and Methods in Physics Research B 259:76.CrossRefGoogle Scholar
Yamamura, Y, Tawara, H. 1996. Energy dependence of ion-induced sputtering yields from monatomic solids at normal incidence. Atomic Data and Nuclear Data Tables 62:2 CrossRefGoogle Scholar
Zecca, A, Karwasz, P, Brusa, RS. 1996. One century of experiments on electron-atom and molecule scattering: a critical review of integer cross-sections. Rivista del Nuovo Cimento 19(3):1.CrossRefGoogle Scholar