氮分子离子N+2和氮原子离子N+与Ne原子碰撞激发的比较

用发射光谱法研究了同种元素氮的分子离子N⁺₂和原子离子N⁺与Ｎｅ原子碰撞产生的激发态，获得了靶激发、入射分子离子的分解激发、入射原子离子的激发以及两种离子与靶之间的电荷转移激发等信息．计算了各发射谱线的发射截面．对两种离子引起的谱线发射截面的差异进行了分析，得出一些初步结论，并对此作了些定性解释     

Electron-impact excitation of the S°, P°, and D° doublet levels of cobalt atoms

The excitation of transitions from the ² S ^∘, ² P ^∘, and ² D ^∘ levels of the cobalt atom is studied by the method of extended crossing beams. Seventy-six excitation cross sections are measured at an exciting electron energy of 50 eV. Nine optical excitation functions are recorded in the electron energy region of 0–200 eV. Possible channels of excitation of levels under study are discussed.     

Excitation of transitions terminating at the 4f 12(3 H)5d6s 2(6,3/2) levels of the thulium atom

The excitation of transitions terminating at the 4f ¹²(³ H)5d6s ²(6,3/2) levels of the thulium atom are studied experimentally. Seventy-five cross sections of the TmI spectral lines are measured at an excitation electron energy of 50 eV. Five optical excitation functions are recorded in the electron energy range of 0–200 eV.     

Coincidence studies with polarisation analysis of the photon emission induced inK-inert gas collisions

The linear and circular polarisations of theK(4² P→4² S) transition detected in delayed coincidence with the inelastically scattered potassium atom are presented forK- He, Ne, Ar, Kr and Xe. For all systems the Stokes vector measurements have been performed as a function of the potassium scattering angle at a beam energy of 10³ eV. The coherence properties of the excitation process are studied with the help of the measured degree of polarisation. For He, Ne and Xe the excitation amplitudes (e.g. the parametersλ andχ) are deduced from the measured Stokes vector. For Ar and Kr the collisionally excited state is not a pure state, and it is concluded that both single excitation of theK atom and simultaneous excitation of both collision partners contribute toK(4² P) excitation. The results are compared with the predictions of the semiclassical treatment of the excitation process.     

Experimental determination and interpretation of the fluorescence and fluorescence excitation spectra of chrysene cooled in a supersonic jet

The fluorescence and fluorescence excitation spectra of jet-cooled chrysene are measured. The frequencies of in-plane vibrations in the ground and first excited singlet electronic states, as well as the relative intensities of transitions between them, are calculated with the MO/M8ST method. Based on these data, experimental spectra are interpreted. In the fluorescence excitation spectrum, the position of the line of the 0–0 transition (28 195 ± 1 cm^?1), which is the most intense, is determined. In the experimental fluorescence excitation spectrum, 21 lines correspond to fundamental vibrations (altogether, 37 lines are attributed). This supports our assignment and is consistent with the group-theoretical analysis of vibronic interactions. Upon excitation at the frequency of the 0–0 transition, 10 lines corresponding to the excitation of fundamental vibrations are detected, and all 17 lines observed are attributed. In the fluorescence excitation spectrum, the standard deviation between the calculated and measured frequencies of attributed fundamental vibrations is 19 cm^?1, while that in the fluorescence spectrum is 15 cm^?1.     

Excitation of deformation vibrations by radiationless muonic transitions

An investigation is carried out for selected doubly even nuclei in the rare-earth and actinide regions for possible resonances between pairs of muonic levels of the appropriate quantum numbers and certain nuclear collective states. Such resonances can lead to the excitation of the particular nuclear state involved, and could be used as an alternate means of nuclear excitation. Electric monopole excitations were found which can result in the excitation of the nuclear 0⁺ level of the β-band. The muonic states involved, however, are such that the probability of nuclear excitation may be small. An electric quadrupole resonance in ¹⁸²W involving the excitation of the 2⁺ state of the β-band is found to be a very likely candidate. Dipole and octupole resonances were also investigated; however no possible resonances were found. Also unsuccessful was the search for quadrupole excitations of the 2⁺ state in the γ-band. The matrix elements involved in the EO and E2 resonances are calculated, the nuclear contribution being computed using the nuclear collective model of Davydov and Chaban. The probability for nuclear excitation in the E2 resonance in ¹⁸²W is computed.     

Spectral dependent kinetics of the EHD luminescence in As-doped Ge

Following pulsed laser excitation of As-doped Ge with impurity concentrations between 10¹⁵-10¹⁷cm^-3, we observe the electron-hole drop (EHD) and excitonic luminescence decay. The spectrum resolved no-phonon (NP) EHD luminescence kinetics are found to depend on its spectral position. “Plateaus” on the kinetic curves for the high energy side of NP-spectrum are observed at high excitation. The data suggest this luminescence is due to the states which are in dynamical equilibrium during some time after excitation pulse.     

Coulomb-nuclear interference at sub-Coulomb energies

The Coulomb-nuclear interference pattern in the low-energy heavy-ion excitation of nuclei near closed-shells can be used to investigate the nuclear mass density at large distances, the nature of the effective transition operator and the presence of higher-order direct processes. Semimicroscopic single-folding calculations are compared to low-energy data for ¹⁸O excitation by ²⁰⁸Pb. A strong effect of two-step transfer reactions is predicted in the sub-Coulomb excitation of ¹⁷O by ²⁰⁸Pb.     

Intra-center energy transfer dynamics in Cd1−xMnxTe semi magnetic semiconductors

Intra-center luminescence of Cd_1?xMn_xTe semi magnetic semiconductors under low excitation density was investigated both experimentally and by Monte-Carlo simulation. Experimental time-resolved spectra of 2 eV-band under different photon energy for excitation were used. The approach revealed that Mn²⁺–Mn²⁺excitation energy transfers take place by means of resonant dipole–dipole interaction. Besides energy transfer dynamics is strongly influenced by hopping-assisted quenching. Having been intra-center excitation selective-, mixed- and non-selective types of excitation are proved to occur if photon energy for excitation is increased. This is originated from overlapping of ⁴T₁- and ⁴T₂-states. Under inter-band excitation it was established that Mn²⁺-ion excitation takes place with the aid of excitonic energy transfer, with excitation energy being centered at exciton energy. Under temperature rise the transfer rate vigorously enhances due to great increase of overlap integral of Mn²⁺- ions' side-bands. The quenching is proved to be limited in accordance with existing theory. Inhomogeneous broadening diminishes as a result of fast fluctuation rate of excited ions' energy.     

Spectrum Simulation of Li-Like Aluminium Plasma

X-ray emission spectra for L-shell of Li-like aluminium ions are simulated by using the flexible atomic code based on the collisional radiative model. Atomic processes including radiative recombination, dielectronic recombination, collisional ionization and resonance excitation from the neighbouring ion （Al^9＋ and Al^11＋ ） charge states of the target ion （Al^10＋） are considered in the model. In addition, the contributions of different atomic processes to the x-ray spectrum are analysed. The results show that dielectronic recombination, radiative recombination, collisional ionization and resonance excitation, other than direct collisional excitation, are very important processes.     

Excitation cross sections of thulium atom transitions terminating at 4f13(2Fo)6s6p(3Po (7/2, J2) levels with J2 = 0, 1

The excitation of odd levels of the thulium atom, spontaneous transitions from which terminate at the 4f ¹³(² F ^o)6s6p(³ P ^o) (7/2, J ₂) levels with J ₂ = 0, 1, is studied by the method of extended crossing beams. Fifty four excitation cross sections are measured at an excitation electron energy of 50 eV. Seven optical excitation functions are recorded in the electron energy range of 0–200 eV.     

Intensitätsmessung von Röntgen- und Kerngammastrahlung an einigen schweren Myonenatomen

Absolute intensities of the 5–4 muonic X-ray transition in muonic W, Os, and Bi, and relative intensities of other X-ray transitions have been measured and compared with cascade calculations. The excitation of several levels in W, Os, Ir, Tl, and Bi nuclei resulting from the muonic cascade process has been observed and absolute excitation probabilities have been determined. For the first 2⁺ level of¹⁸⁸Os and the first 3/2⁺-levels of^203,205Tl the excitation probabilities are larger than calculated. The results are discussed.     

The excitation cross section of cadmium atoms from metastable 5<Emphasis Type="Italic">s</Emphasis>5<Emphasis Type="Italic">p</Emphasis><Superscript>3</Superscript><Emphasis Type="Italic">P</Emphasis><Subscript>0, 2</Subscript> states by electron impact

By means of the optical method using the technique of crossed electron and atomic beams, we obtained the absolute values of the excitation cross sections of metastable cadmium atoms and their energy dependences. The absolute cross section values reach ∼10⁻¹⁶ cm² (at 30 eV). Sharp resonance-like maxima are observed in the energy dependences of the excitation cross section near the excitation thresholds, which are supposedly related to the formation and decay of negative-ion excited states of.     

Coulomb-nuclear interference for inelastic deuteron scattering

The interference between Coulomb excitation and nuclear excitation has been observed for ^{54, 56}Fe, ⁶⁰Ni, ¹¹⁴Cd, ¹⁵²Sm, and ¹⁹²Os by measuring excitation functions of elastic and inelastic deuteron scattering at back angles. The interference is strongly constructive, indicating a predominantly imaginary nuclear form factor. DWBA calculations using the collective model, although predicting constructive interference, are unable to predict the magnitude of the observed effect.     

Excitation migration among inhomogeneously broadened levels of Eu3+ ions

Excitation migration between ⁵D₀ states of Eu³⁺ ions in Ca(PO₃)₂ glass is studied by using the technique of the selective excitation of the inhomogeneously broadened ⁵D₀ levels. In time-resolved emission spectra for ⁵D₀→⁷F₁ transition after the pulse excitation due to ⁷F₀→⁵D₀ transition by the use of a tunable dye laser at 77°K, a subpeak is observed to appear and to grow in intensity with increasing delay time, besides the main peak excited directly by the excitation light. The observed facts are explained by considering the phonon-assisted energy transfer between ⁵D₀ states involving an acoustic phonon. From the analysis of the results, the probability of the excitation migration due to the phonon-assisted process is estimated to be ≌ 10 A ms^-1. From the theoretical consideration, the rate of the linewidth change and the probability of the excitation migration due to the resonant transfer process are obtained. These results indicate that the phonon-assisted process is more dominant than the resonant process for the excitation migration in the system studied.     

Dissociative excitation of the odd quartet <Emphasis Type="Italic">S,P, D</Emphasis>, and <Emphasis Type="Italic">F</Emphasis> levels of the manganese atom in e-MnCl<Subscript>2</Subscript> collisions

The dissociative excitation of the ⁴ S°, ⁴ P°, ⁴ D°, and ⁴ F° levels of the manganese atom in collisions of slow electrons iwth manganese dichloride molecules is studied experimentally. It is found that the dissociative excitation cross sections for these levels are larger than the cross sections of direct excitation in the e-Mn collisions. The cross section ratios of the electron-atom and electron-molecule collisions, which characterize the effect of the chemical bond of the manganese atom with the halogen on the absolute excitation cross sections, are determined.     

On the inelastic excitation of 2− state of 16O by α particles

The excitation of the unnatural parity state (2^?, 8.87 MeV) of ¹⁶O by inelastic scattering of 40 MeV α particle is investigated microscopically. The two step excitation mechanism via the 3^? state at 6.13 MeV is found to reproduce the magnitude of the measured cross section of the 2^- excitation. The α-nucleon interaction used for the 2^- excitation also reproduces the 3^- excitation.     

Raman excitation profiles of adsorbates at roughened silver surfaces

The excitation profiles of Raman bands of pyridine (1008 cm^?1), triphenylphosphine (997 cm^?1), [CN]^? (2114 cm^?1), and [Ru₃O₂(NH₃)₁₄]⁶⁺ (ruthenium red, 275 cm^?1) adsorbed at roughened silver-aqueous interfaces have been measured over the range 458–799 nm. Apart from [CN]^? for which experimental limitations prevented measurements with excitation in the far red, each of the adsorbates shows a pronounced excitation profile maximum for excitation in the range 590–750 nm. Measurements on triphenylphosphine at a silver-aqueous interface and on the same silver surface in gaseous nitrogen detected some difference in the excitation profiles due to change of medium. These results are discussed in relation to various theories of enhanced Raman scattering by adsorbates at metal surfaces.