2001 Fiscal Year Final Research Report Summary
Measurement of Emission Cross Sections for Inert-gas Atoms by Electron Impact
| Project/Area Number |
11440122
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物理学一般
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
TSURUBUTI Seiji Tokyo University of Agriculture and Technology, Department of Applied Physics, Professor, 工学部, 教授 (60028248)
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| Co-Investigator(Kenkyū-buntansha) |
MOTOHASHI Kenji Tokyo University of Agriculture and Technology, Department of Applied Physics, Research Assistant (50251583)
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| Project Period (FY) |
1999 – 2001
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| Keywords | electron impact / inert-gas atom / emission cross section / evel excitation cross section / apparent excitation cross section / the 2p_9 state / resonance line / time-resolved measurement |
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| Research Abstract |
Emission cross sections for the np→ns and ns→(n-1)p transitions (Ne : n=3, Ar : n=4, Kr : n=5) of inert-gas atoms have been systematically measured from threshold to 1000 eV in the period of 1991〜2000. We have determined absolute emission cross sections as well as the total cascade cross sections to the ns-state in the visible wavelength range. However, a further reconfirmation had been desired for the absolute optical sensitivity in the near infrared wavelength range of the detection system where no standard lamp was available. We adopted a so-called brandling method utilizing Ar spectra. The obtained cross sections show considerable differences in part with those results previously reported.
The 2p_9 → 1s_5 transition in Paschen notation is of particular interest because the 2p_9 state is a pure triplet state and well represented by the term^3 D_3 in the LS-scheme. Theoretical excitation cross sections for the 2p_9 state of Ar and Kr show almost 〜 E^<-3> dependence on the impact energy E, whereas, the experimentally obtained cross sections descend more slowly. Time-resolved intensity decays of the 2p_9 → 1s_5 transition show that the most of the population of the 2p_9 state is due to the cascade transitions from the higher lying Rydberg states at high energies.
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