Effect of multiphoton ionization of metastable and ground-state molecules in laser Thomson scattering diagnostics

POSTER

Abstract

In laser Thomson scattering diagnostics of low temperature plasmas, the probe laser beam is focused to obtain a sufficient signal to noise ratio, and the laser energy density in the focal region is very high. Therefore, one must be certain that possible electron production due to multiphoton ionization is negligible in comparison with the unperturbed plasma electron density. We are carrying out a systematic study of determining multiphoton ionization efficiency in the focal region of frequency-double Nd:YAG laser (532 nm). The laser beam is focused between the electrodes of a small dc-biased parallel-plate probe, whose current due to the collected charge arising from multiphoton ionization is detected by a digital oscilloscope. Preliminary results indicate the following. For 200-mJ laser pulse focused with a f=400 mm lens, metastable Ar atoms are ionized with a high probability, while no significant ionization occurs for ground-state Ar atoms. Ground-state O$_{2}$ molecules give rather large multiphoton ionization signal and Thomson scattering measurements for medium pressure (1$>$Torr) O$_{2}$ plasma would require careful control of laser energy density in the focal region. Measurements for other gases are in progress.

Authors

  • A. Kono

  • Jeffrey L. Putney

    IBM Research, Advanced Micro Devices, Applied Materials, Inc., IMEC v.z.w. 75 Kapeldreef B-3001 Leuven, Belgium, Kyoto University, Nagoya University, Dublin City University, Ireland, ARC CAMS, MPIT, JCU, Australia, INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany, TU Clausthal, MPI Heidelberg, MPI Dresden, Curtin University of Technology, Australian National University, Missouri University of Science \& Technology, Ruhr University Bochum, Hungarian Academy for Science, RLS-M, OSRAM GmbH, Munich, Germany, INP Greifswald, Germany, Ruhr-University of Bochum, Germany, Nagoya University, JST, CREST, Osaka University, JST, CREST, Kyushu University, JST, CREST, Kyushu University, National Institute for Material Physics, National Institute for Laser, Plasma and Radiation Physics, Arizona State University, Naval Research Laboratory, McGill University, Laboratoire EM2C, CNRS UPR288, Ecole Centrale Paris, Dow Corning Plasma Solutions, Midleton, Ireland, Centre for Plasma Physics, Queens University Belfast, Northern Ireland, University of Adelaide, Adelaide, Australia, University of Central Florida, Orlando, FL, Missouri S\&T, Rolla, MO, University of Manchester, Manchester, UK, Missouri University of Science and Technology, Rolla, Missouri, USA, ARC Centre for Antimatter-Matter Studies, University of Adelaide, 5005, Australia, NU Eco-Engineering Co., Ltd., Fuji Machine Mfg. Co., Ltd., Meijo University, Katagiri Engineering Co., Ltd., Dept. of Electrical Engineering, University of Texas at Dallas, The University of Texas Southwestern Medical Center at Dallas, NU System Co., Ltd., NU EcoEngineering Co., Ltd., Wakayama University, Department of Electronic Science and Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan, Muroran Institute of Technology, Nippon Steel Corporation, B and W Group Ltd, The University of Texas at Dallas, Ruhr-University Bochum, Lehrstuhl f. Theoretische Elektrotechnik, 44801 Bochum, Germany, Ruhr-University Bochum, Inst. for Plasma and Atomic Physics, 44780 Bochum, Germany, Ruhr University Bochum, TET, Ruhr University Bochum, AEPT, Tokyo Electron America, University of Houston, IEAP, Christian-Albrechts-Universit\"{a}t, Kiel, INP\,Greifswald, Germany, Nagoya Institute of Technology, Institute for Theoretical and Experimental Physics, Federal State Unitary Enterprise and Moscow Institute of Electronic Technology, Federal State Unitary Enterprise, PLASMANT Research Group, Dept. of Chemistry, Univ. of Antwerp, Arbeitsgruppe Reaktive Plasmen, Fakult\"at f\"ur Physik und Astronomie, Ruhr-Universit\"at Bochum, PIIM, CNRS - Universite de Provence, LPTP, Ecole Polytechnique, Laplace, Universite Paul Sabatier, Institute of Plasma Physics AS CR, v.v.i., Hokkaido Univ., NIT, Chiba Institute of Technology, The University of Tokushima, Ruhr-University Bochum, TET, Ruhr-University Bochum, AEPT, IPFN IST Lisboa, LPGP UPS Orsay, Tokyo Electron Ltd., Keio University, Tokyo Institute of Technology, Max-Planck-Institut f\"ur Kernphysik, Institut f\"ur Theoretische Physik, TU Clausthal, Curtin University, Perth, Australia, Max-Planck-Institut fur Kernphysik, Missouri University of Science and Technology, NRL, Berkeley Scholars Inc., Department of Physics, Florida A\&M University, Department of Physics, University of Rajshahi, Rajshahi, Bangladesh, Max-Planck-Institute for Nuclear Physics, Heidelberg, Germany, Nicolaus Copernicus University, Institute of Physics, Grudziadzka 5/7, 87-100 Torun, Poland, CAMS, Australian National University, York University, Canada, University of Wisconsin, Florida Tech, Depoartment of Physics, Florida A\&M University, Lamar University, Institute of Semiconductor Physics, 630090 Novosibirsk, Russia, Max-Planck-Institut f\"ur Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany, University of Adelaide, Max-Planck Inst. fuer Kernphysik, Heidelberg, Kansas State University (now University of Madrid), Lawrence Berkeley National Laboratory and University of California, Davis, Lawrence Berkeley National Laboratory, Max-Planck Institut fuer Kernphysik, Heidelberg, Kansas State University, University of Madrid, National Institute for Laser, Plasma and Radiation Physics, Romania, INP Greifswald, Felix-Hausdorff-Str. 2, D-17489 Greifswald, Germany, Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, Hanyang University, University of Wisconsin-Madison, WVU, ISSI, Inc., UES, Inc., University of Texas at Dallas, Verity Instruments, University of Illinois at Urbana-Champaign, LPTP, CNRS, France, University of Wyoming, Institute of Solid State Physics of Bulgarian Academy of Sciences, Sofia, Bulgaria, Institute of Physics, Belgrade, Serbia, ISSI Inc., West Virginia University, St. Petersburg State University, Nagasaki University, Link\"oping University, Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523., Tokyo Tech., Nagoya UNiversity, Air Force Research Laboratory, Wright-Patterson AFB, OH 45433, Innovative Scientific Solutions, Inc., Dayton, OH 45440, Electrical Engineering, Hanyang University, Republic of Korea, Department of Physics, Wesleyan University, Middletown, USA, Universidade Estadual de Campinas- Unicamp, Campinas, Brazil, DMS Co., Ltd., Suwon, 445-810, Korea, Department of Chemical Engineering, Sungkyunkwan University, Suwon, 440-746, Korea, Varian Semiconductor Equipment Associates, Department of Chemistry and Division Energy Systems Research, Ajou University, Suwon 443-749, Korea, Nagoya Univ. and JST-CREST, Kyushu Univ. and JST-CREST, Osaka Univ. and JST-CREST, Nagoya Urban Industries Promotion Corp., Universidad de Antioquia, Columbia, Loras College, Universidad Autonoma de Madrid, LBL, University of Newcastle, University of Nebraska, Lawrence Berkeley National Lab and University of California, Davis, Lawrence Berkeley National Lab, Universidad Autonoma de Madrid, Spain, University of California, Davis, LPTP, Palaiseau, France, LSP, Grenoble, France, Queen's University Belfast, Ruhr-Universitaet Bochum, Laboratory for Optical Physics and Engineering, University of Illinois at Urbana-Champaign

  • Jeffrey L. Putney

    IBM Research, Advanced Micro Devices, Applied Materials, Inc., IMEC v.z.w. 75 Kapeldreef B-3001 Leuven, Belgium, Kyoto University, Nagoya University, Dublin City University, Ireland, ARC CAMS, MPIT, JCU, Australia, INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany, TU Clausthal, MPI Heidelberg, MPI Dresden, Curtin University of Technology, Australian National University, Missouri University of Science \& Technology, Ruhr University Bochum, Hungarian Academy for Science, RLS-M, OSRAM GmbH, Munich, Germany, INP Greifswald, Germany, Ruhr-University of Bochum, Germany, Nagoya University, JST, CREST, Osaka University, JST, CREST, Kyushu University, JST, CREST, Kyushu University, National Institute for Material Physics, National Institute for Laser, Plasma and Radiation Physics, Arizona State University, Naval Research Laboratory, McGill University, Laboratoire EM2C, CNRS UPR288, Ecole Centrale Paris, Dow Corning Plasma Solutions, Midleton, Ireland, Centre for Plasma Physics, Queens University Belfast, Northern Ireland, University of Adelaide, Adelaide, Australia, University of Central Florida, Orlando, FL, Missouri S\&T, Rolla, MO, University of Manchester, Manchester, UK, Missouri University of Science and Technology, Rolla, Missouri, USA, ARC Centre for Antimatter-Matter Studies, University of Adelaide, 5005, Australia, NU Eco-Engineering Co., Ltd., Fuji Machine Mfg. Co., Ltd., Meijo University, Katagiri Engineering Co., Ltd., Dept. of Electrical Engineering, University of Texas at Dallas, The University of Texas Southwestern Medical Center at Dallas, NU System Co., Ltd., NU EcoEngineering Co., Ltd., Wakayama University, Department of Electronic Science and Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan, Muroran Institute of Technology, Nippon Steel Corporation, B and W Group Ltd, The University of Texas at Dallas, Ruhr-University Bochum, Lehrstuhl f. Theoretische Elektrotechnik, 44801 Bochum, Germany, Ruhr-University Bochum, Inst. for Plasma and Atomic Physics, 44780 Bochum, Germany, Ruhr University Bochum, TET, Ruhr University Bochum, AEPT, Tokyo Electron America, University of Houston, IEAP, Christian-Albrechts-Universit\"{a}t, Kiel, INP\,Greifswald, Germany, Nagoya Institute of Technology, Institute for Theoretical and Experimental Physics, Federal State Unitary Enterprise and Moscow Institute of Electronic Technology, Federal State Unitary Enterprise, PLASMANT Research Group, Dept. of Chemistry, Univ. of Antwerp, Arbeitsgruppe Reaktive Plasmen, Fakult\"at f\"ur Physik und Astronomie, Ruhr-Universit\"at Bochum, PIIM, CNRS - Universite de Provence, LPTP, Ecole Polytechnique, Laplace, Universite Paul Sabatier, Institute of Plasma Physics AS CR, v.v.i., Hokkaido Univ., NIT, Chiba Institute of Technology, The University of Tokushima, Ruhr-University Bochum, TET, Ruhr-University Bochum, AEPT, IPFN IST Lisboa, LPGP UPS Orsay, Tokyo Electron Ltd., Keio University, Tokyo Institute of Technology, Max-Planck-Institut f\"ur Kernphysik, Institut f\"ur Theoretische Physik, TU Clausthal, Curtin University, Perth, Australia, Max-Planck-Institut fur Kernphysik, Missouri University of Science and Technology, NRL, Berkeley Scholars Inc., Department of Physics, Florida A\&M University, Department of Physics, University of Rajshahi, Rajshahi, Bangladesh, Max-Planck-Institute for Nuclear Physics, Heidelberg, Germany, Nicolaus Copernicus University, Institute of Physics, Grudziadzka 5/7, 87-100 Torun, Poland, CAMS, Australian National University, York University, Canada, University of Wisconsin, Florida Tech, Depoartment of Physics, Florida A\&M University, Lamar University, Institute of Semiconductor Physics, 630090 Novosibirsk, Russia, Max-Planck-Institut f\"ur Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany, University of Adelaide, Max-Planck Inst. fuer Kernphysik, Heidelberg, Kansas State University (now University of Madrid), Lawrence Berkeley National Laboratory and University of California, Davis, Lawrence Berkeley National Laboratory, Max-Planck Institut fuer Kernphysik, Heidelberg, Kansas State University, University of Madrid, National Institute for Laser, Plasma and Radiation Physics, Romania, INP Greifswald, Felix-Hausdorff-Str. 2, D-17489 Greifswald, Germany, Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, Hanyang University, University of Wisconsin-Madison, WVU, ISSI, Inc., UES, Inc., University of Texas at Dallas, Verity Instruments, University of Illinois at Urbana-Champaign, LPTP, CNRS, France, University of Wyoming, Institute of Solid State Physics of Bulgarian Academy of Sciences, Sofia, Bulgaria, Institute of Physics, Belgrade, Serbia, ISSI Inc., West Virginia University, St. Petersburg State University, Nagasaki University, Link\"oping University, Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523., Tokyo Tech., Nagoya UNiversity, Air Force Research Laboratory, Wright-Patterson AFB, OH 45433, Innovative Scientific Solutions, Inc., Dayton, OH 45440, Electrical Engineering, Hanyang University, Republic of Korea, Department of Physics, Wesleyan University, Middletown, USA, Universidade Estadual de Campinas- Unicamp, Campinas, Brazil, DMS Co., Ltd., Suwon, 445-810, Korea, Department of Chemical Engineering, Sungkyunkwan University, Suwon, 440-746, Korea, Varian Semiconductor Equipment Associates, Department of Chemistry and Division Energy Systems Research, Ajou University, Suwon 443-749, Korea, Nagoya Univ. and JST-CREST, Kyushu Univ. and JST-CREST, Osaka Univ. and JST-CREST, Nagoya Urban Industries Promotion Corp., Universidad de Antioquia, Columbia, Loras College, Universidad Autonoma de Madrid, LBL, University of Newcastle, University of Nebraska, Lawrence Berkeley National Lab and University of California, Davis, Lawrence Berkeley National Lab, Universidad Autonoma de Madrid, Spain, University of California, Davis, LPTP, Palaiseau, France, LSP, Grenoble, France, Queen's University Belfast, Ruhr-Universitaet Bochum, Laboratory for Optical Physics and Engineering, University of Illinois at Urbana-Champaign