Search results

1

State-to-State Cross Sections for Rotationally Inelastic Collision of He with Na_2

100%

Wang Y.

Acta Physica Polonica A

|

2011

|

vol. 119

|

issue 3

354-358

EN

As a further theoretical study of the collision-induced quantum interference on rotational energy transfer in an atom-diatom system, the differential interference angles for singlet-triplet mixed states of Na_2 system in collision with He were calculated based on the first-Born approximation of time-dependent perturbation theory, taking into account the anisotropic Lennard-Jones interaction potential and the long-range interaction potential. The relationships of differential interference angle versus impact parameter including collision parameter, velocity, are obtained. It is beneficial to reduce the loss in molecular cooling and trapping.

2

Long-range Interactions for the A^31_u and B^30^+_u States of Cd_2 from Line Shape Measurements

51%

Grycuk T., Michalicka M., Rogaczewski J.

Acta Physica Polonica A

|

2002

|

vol. 101

|

issue 6

825-836

EN

We report on very precise measurements of the absorption profile of the 326.1 nm resonance line of cadmium broadened by interactions with the ground state Cd atoms under thermal equilibrium. The experimental red wing profiles, corrected for the Boltzmann factor at different temperatures, are analysed in terms of the long-range potential parameters including dispersion and resonant interactions. The resonant interaction energy constant C_3 is calculated to be 2.31×10^{-2} eV Å^3 and the van der Waals constant C_6 for difference potentials between the ground state X^10^+_ g and the excited states B^30^+_u and A^31_u of Cd_2 derived experimentally are found to be (182.6± 8) eV Å^6 and (289±4) eV Å^6, respectively. The former is determined for the first time and the latter is considerably corrected in comparison to earlier determination. The van der Waals constant C_6 for the ground state of Cd_2 is discussed and estimated to be C_6^g=(247± 40) eV Å^6.

3

Collision-Time Asymmetry and Speed-Dependent Effects on the ^{114}Cd 326.1 nm Line Perturbed by Kr

51%

Trawiński R., Bielski A., Lisak D.

Acta Physica Polonica A

|

2001

|

vol. 99

|

issue 2

243-256

EN

Using a laser-induced fluorescence method, detailed analysis of profiles of the ^{114}Cd 326.1 nm line perturbed by krypton was performed which revealed departures from the ordinary Voigt profile. These departures are shown to be consistent with fits of experimental profiles to a speed-dependent asymmetric Voigt profile. Coefficients of the pressure broadening, shift, and collision-time asymmetry are determined and compared with those calculated in the adiabatic approximation for the van der Waals, Czuchaj-Stoll, and Morse potentials.

4

Microscopic Investigation of SiC Epitaxial Layers οn On-Axis 4H-SiC Substrates Using Kelvin Probe Force Microscopy

51%

Kościewicz K., Bożek R., Strupiński W., Olszyna A.

Acta Physica Polonica A

|

2009

|

vol. 116

|

issue S

S-69-S-71

EN

We report on Kelvin probe force microscopy and electron backscatter diffraction measurements of 3C-SiC epitaxial layers grown on exactly oriented Si-face 4H-SiC (0001) substrates in a horizontal hot-wall chemical vapor deposition reactor, in the temperature range from 1150°C to 1620°C, under H_{2} or H_{2} +SiH_{4} atmosphere. The investigated layers were doped with nitrogen (for n-type) and aluminium (for p-type). The electron backscatter diffraction analysis revealed structure of polytype 3C blocks with a relative rotation of 60 and/or 120°. The Kelvin probe force microscopy measurements revealed cubic substructure as a equilateral triangle objects contrast which is characteristic of 3C silicon carbide polytype. The surface potential contrast was found to be dependent on the type and concentration of doping, which could be explained in terms of the impurities accumulation at block boundaries.

5

Pressure Broadening and Shift of the 326.1 nm Cd Line Perturbed by H_{2} and D_{2}

51%

Bielski A., Ciuryło R., Domysławska J., Lisak D., Trawiński R., Wolnikowski J.

Acta Physica Polonica A

|

2000

|

vol. 97

|

issue 6

1003-1010

EN

The experimental values of pressure broadening and shift coefficients of the ^{114}Cd 326.1 nm line perturbed by H_{2} and D_{2} are determined using a LIF technique and compared with theoretical values calculated from the impact theory.

6

Effects of Low-Polarizability Perturbers on the Cadmium Intercombination Line

51%

Bielski A., Lisak D., Trawiński R., Szudy J.

Acta Physica Polonica A

|

2003

|

vol. 103

|

issue 1

23-40

EN

Using a laser-induced fluorescence method a detailed analysis of profiles of the ^{114}Cd 326.1 nm line perturbed by neon and helium was performed which revealed deviations from the ordinary Voigt profile. These deviations are shown to be consistent with fits of experimental profiles to an asymmetric Voigt profile. Coefficients of the pressure broadening, shift and collision-time asymmetry are determined and compared with those calculated in the adiabatic approximation for different interaction potentials.

7

On Argon-Induced Pressure Shifts of ^{198}Hg Spectral Lines Associated with Quasi-Rydberg Transitions

51%

Trawiński R.

Acta Physica Polonica A

|

2006

|

vol. 110

|

issue 1

51-56

EN

The extended Omont-Kaulakys-Ueda treatment of collisional effects on quasi-Rydberg states, in which the perturbation of the lower state is taken into account, is applied to mercury-argon system. The pressure shift coefficients of 6p-ns and 6p-nd spectral lines are calculated and compared with available experimental data.

8

Stereoselectivity Effect on Tb(III)-Eu(III) Energy Transfer in Complexes with Glutamic Acid and Alanine

51%

Legendziewicz J., Huskowska E., Stręk W., Łukowiak E., Sztucki J.

Acta Physica Polonica A

|

1993

|

vol. 84

|

issue 5

1021-1024

EN

The effect of stereoselectivity on energy transfer between Tb(III) and Eu(III) in crystals with glutamic acid and alanine was investigated. It was found that the stereoselectivity significantly changes the energy transfer in these systems. The theoretical model for the selective dependent energy transfer processes in lanthanide systems is developed and the nature of processes occurring in both systems under investigation briefly discussed.

9

Intermolecular Energy Transfer Between Lanthanide Complex Ions in Micellar Solution

51%

Dong W., Flint C.

Acta Physica Polonica A

|

1993

|

vol. 84

|

issue 5

985-992

EN

Two different procedures for the study of the quenching of excited states by lanthanide complex ions on the surface of micelles are considered. In the first, excited Tb(pdc)_{3}^{3-} (pdc = pyridine 2,6-dicarboxylate) complex ions are held in close proximity to other Ln(pdc)_{3}^{3-} ions on the surface of cetyl trimethyl ammonium micelles. Efficient energy transfer is observed by the electric dipole-electric dipole mechanism with a mean interaction distance only slightly greater than that which exists in the crystalline complexes. In the second, the excited state of Tb(pdc)_{3}^{3-} is depopulated by energy transfer to the coexcited lowest excited triplet state of phenanthrene which is thereby excited to the second triplet state.

10

Influence of Excitation Processes on the Shape of Argon and Neon Lines

51%

Bielski A., Ciuryło R., Lisak D., Trawiński R.

Acta Physica Polonica A

|

2000

|

vol. 97

|

issue 2

275-284

EN

Shapes of self-broadened argon lines 687.1 nm (4d_{5}-2p_{10}), 703.0 nm (3s_{5}-2p_{9}), 750.3 nm (2p_{1}-1s_{2}) as well as the neon line 748.8 nm (3d_{3}-2p_{10}) emitted from glow discharges at low pressures were analysed using a Fabry Perot interferometer. We showed that the dissociative recombination of Ar^{+}_{2} (or Ne^{+}_{2}) molecular ions which gives rise to the density of non-thermalized atoms, may be regarded as the main process responsible for the distortion of the profiles of the above lines. The distorted profiles were analysed as superposition of the Ballik profile for thermalized atoms and the modified Ballik profile for non-thermalized atoms. The Lorentzian and Gaussian widths as well as relative densities of non-thermalized and thermalized atoms were determined.

11

Non-Adiabatic Semiclassical Calculations of the Collision-Time Asymmetry of the ^{114}Cd 326.1 nm Line Perturbed by Noble Gases

51%

Bielski A., Ciuryło R., Lisak D., Trawiński R., Orlikowski T.

Acta Physica Polonica A

|

2004

|

vol. 105

|

issue 3

217-232

EN

The collision-time asymmetry coefficients as well as the pressure broadening and shifting rates of the ^{114}Cd 326.1 nm line perturbed by noble gases are calculated in the framework of the non-adiabatic semi-classical method using the Czuchaj et al. potentials. The theoretical values are compared with experimental results determined recently by means of laser-induced fluorescence technique.

12

Observation of the Line-Mixing and Collision-Time Asymmetry of the 5^{1}S_0-5^{3}P_1 Line of the Even-Odd ^{113}Cd Isotope

51%

Bielski A., Ciuryło R., Domysławska J., Lisak D., Masłowski P., Szudy J., Trawiński R.

Acta Physica Polonica A

|

2004

|

vol. 105

|

issue 4

329-338

EN

The profiles of argon perturbed components of the 5^{1}S_0-5^{3}P_1 line of the even-odd ^{113}Cd isotope were measured using a laser-induced fluorescence method. It was shown that the asymmetries of the profiles are due to both the collision-duration and line-mixing effects.

13

Speed-Dependent Effects on the 748.8 nm Ne Self-Broadened Line

51%

Ciuryło R., Bielski A., Brym S., Domysławska J., Lisak D., Szudy J., Trawiński R.

|

vol. 96

|

issue 3-4

359-372

EN

Profiles of the self-broadened 748.8 nm Ne line emitted from a glow discharge in neon in the pressure range between 0.8 and 100 Tr were measured using an improved experimental setup with pressure-scanned Fabry-Perot interferometer. First, line profiles were analysed using an ordinary Voigt procedure which yielded the Doppler widths decreasing with the increase in neon pressure. Using a speed-dependent Voigt profile it was shown that for the 748.8 nm line the correlation between the Doppler and collisional broadening plays an important role. However, the values of the pressure broadening and shift coefficients determined by the speed-dependent Voigt analysis were found to be only slightly different from those obtained by the ordinary Voigt analysis. A systematic error in the determination of perturber concentration in our previous investigation was corrected.

14

Long-Range Interactions and the Oscillator Strength for the 1_u, 0^+_u → X 0^+_g Transitions in Zn_2

45%

Kubkowska M., Szczęśniak T., Grycuk T.

Acta Physica Polonica A

|

2004

|

vol. 105

|

issue 4

317-328

EN

The interaction potentials for Zn_2 electronic states {1}_u and {0}_u^+ correlated with (4 {1}^P_1+4 {1}^S_0) asymptote in the long-range region (10-25) Å and the oscillator strength f for the absorption transition to these states are derived experimentally from a careful analysis of the self-broadened resonance 213.8 nm line of Zn. It is found that although the interatomic interactions at so long distances are dominated by resonance potential of the form C_3/R^3 resulting in the Lorentzian line shape, the parameter C_3 and thus f value significantly decrease with R decreasing. This effect proved to be a linear function of R^{-1} yielding the oscillator strength for the considered line f_0=1.456 ± 0.010 from R → ∞ extrapolation. This value seems to be the most accurate experimental result as yet and shows that the best theoretical values for this quantity are overestimated. It is suggested that the long-range behaviour of the potential energy curves observed here for the first time represents the effective potentials including dominating resonance interactions and a possible slight contribution of the dispersion interactions as well as the R-dependent spin-orbit interaction.

Refine search results

State-to-State Cross Sections for Rotationally Inelastic Collision of He with Na_2

Long-range Interactions for the A^31_u and B^30^+_u States of Cd_2 from Line Shape Measurements

Collision-Time Asymmetry and Speed-Dependent Effects on the ^{114}Cd 326.1 nm Line Perturbed by Kr

Microscopic Investigation of SiC Epitaxial Layers οn On-Axis 4H-SiC Substrates Using Kelvin Probe Force Microscopy

Pressure Broadening and Shift of the 326.1 nm Cd Line Perturbed by H_{2} and D_{2}

Effects of Low-Polarizability Perturbers on the Cadmium Intercombination Line

On Argon-Induced Pressure Shifts of ^{198}Hg Spectral Lines Associated with Quasi-Rydberg Transitions

Stereoselectivity Effect on Tb(III)-Eu(III) Energy Transfer in Complexes with Glutamic Acid and Alanine

Intermolecular Energy Transfer Between Lanthanide Complex Ions in Micellar Solution

Influence of Excitation Processes on the Shape of Argon and Neon Lines

Non-Adiabatic Semiclassical Calculations of the Collision-Time Asymmetry of the ^{114}Cd 326.1 nm Line Perturbed by Noble Gases

Observation of the Line-Mixing and Collision-Time Asymmetry of the 5^{1}S_0-5^{3}P_1 Line of the Even-Odd ^{113}Cd Isotope

Speed-Dependent Effects on the 748.8 nm Ne Self-Broadened Line

Long-Range Interactions and the Oscillator Strength for the 1_u, 0^+_u → X 0^+_g Transitions in Zn_2