Transfer of Electronic Excitation between the 62P3/2 and 62P1/2 States of Rubidium Induced by Collisions with Rubidium Atoms

1974 ◽  
Vol 52 (17) ◽  
pp. 1635-1640 ◽  
Author(s):  
Paul W. Pace ◽  
J. B. Atkinson
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Electronic Excitation ◽  
Empirical Relationship ◽  
Optical Excitation ◽  
Nitrogen Laser ◽  
Rubidium Vapor ◽  
Rubidium Atoms ◽  
Structure Splitting ◽  
The Cross

The cross sections for excitation transfer between the 62P fine structure levels of rubidium, induced in collisions with ground state rubidium atoms, have been measured using a nitrogen laser pumped dye laser as the optical excitation source in a fluorescence experiment. Rubidium vapor was irradiated with each component of the 2P rubidium doublet in turn, and measurements of the relative intensities of fluorescence yielded the following cross sections: [Formula: see text] These results are consistent with the empirical relationship between the magnitude of the cross sections and the fine structure splitting that has previously been established for the alkalis.

Transfer of Electronic Excitation between the 72P1/2 and 72P3/2 States of Cesium Induced by Collisions with Cesium Atoms

1974 ◽  
Vol 52 (17) ◽  
pp. 1641-1647 ◽  
Author(s):  
Paul W. Pace ◽  
J. B. Atkinson
Keyword(s):  
Cross Sections ◽  
Electronic Excitation ◽  
Empirical Relationship ◽  
Nitrogen Laser ◽  
Mixing Process ◽  
Transfer Processes ◽  
Radiation Trapping ◽  
Structure Splitting ◽  
The Cross ◽  
Cesium Atoms

The method of sensitized fluorescence has been employed to investigate the [Formula: see text] excitation transfer processes in cesium induced in collisions with ground state cesium atoms. The cesium vapor density was kept sufficiently low to enable the cross sections for the mixing process to be determined under single collision conditions and to ensure that radiation trapping and quenching were negligible. A nitrogen laser pumped dye laser was used to excite the cesium atoms to each of the 72P levels in turn and measurements of the relative intensities of fluorescence yielded the following cross sections: [Formula: see text] These results are consistent with the empirical relationship between the magnitude of the cross sections and the fine structure splitting that has previously been determined for the alkalis.

Sensitized Fluorescence in Vapors of Alkali Atoms. XIII. 62P1/2−62P3/2 Excitation Transfer in Rubidium, Induced in Collisions with Noble Gas Atoms

1972 ◽  
Vol 50 (16) ◽  
pp. 1826-1832 ◽  
Author(s):  
I. Siara ◽  
E. S. Hrycyshyn ◽  
L. Krause
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Noble Gas ◽  
Excitation Transfer ◽  
Fluorescent Intensity ◽  
Rubidium Vapor ◽  
Sensitized Fluorescence ◽  
Fine Structure Splitting ◽  
Alkali Atoms ◽  
Structure Splitting

The cross sections for excitation transfer between the 62P fine-structure substates in rubidium, induced in collisions with noble gas atoms, have been determined in a series of sensitized fluorescence experiments. Mixtures of rubidium vapor and noble gases at pressures varying in the range 0–5 Torr were irradiated with each component of the second 2P rubidium doublet in turn and the following cross sections for 2P mixing were obtained from measurements of sensitised-to-resonance fluorescent intensity ratios. Rb–He: Q12(2P1/2 → 2P3/2) = 29.3 Å2; Q21(2P1/2 ← 2P3/2) = 19.0 Å2. Rb–Ne: Q12 = 10.3 Å2; Q21 = 6.4 Å2. Rb–Ar: Q12 = 24.0 Å2; Q21 = 14.9 Å2. Rb–Kr: Q12 = 23.2 Å2; Q21 = 14.6 Å2. Rb–Xe: Q12 = 43.9 Å2; Q21 = 27.7 Å2 In their dependence on the magnitude of the fine-structure splitting, the values are consistent with previously determined cross sections for mixing in the first and third 2P doublets of alkali atoms.

Inelastic Collisions between Excited Alkali Atoms and Molecules. VIII. 62P1/2–62P3/2 Mixing and Quenching in Mixtures of Rubidium with H2, HD, D2, N2, CH4, and CD4

1973 ◽  
Vol 51 (3) ◽  
pp. 257-265 ◽  
Author(s):  
I. N. Siara ◽  
L. Krause
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Ground State ◽  
Inelastic Collisions ◽  
Fluorescent Intensity ◽  
Rubidium Vapor ◽  
Sensitized Fluorescence ◽  
Molecular Gases ◽  
Alkali Atoms ◽  
Intensity Ratios

Excitation transfer between the 62P fine-structure substates in rubidium, induced in inelastic collisions with ground-state molecules, has been studied using techniques of sensitized fluorescence. Rubidium vapor in mixtures with various molecular gases was irradiated with each component of the 2P rubidium doublet in turn, and measurements of sensitized-to-resonance fluorescent intensity ratios yielded the following mixing cross sections Q12(2P1/2 → 2P3/2) and Q21(2P1/2 ← 2P3/2), as well as effective quenching cross sections Q1X(2P1/2 → 2XJ″) and Q2X(2P3/2 → 2XJ″). For collisions with H2: Q12(2P1/2 → 2P3/2) = (41 ± 5) Å2; Q21(2P1/2 ← 2P3/2) = (26 ± 3) Å2; Q1X(2P1/2 → 2XJ″) = (36 ± 9) Å2; Q2X(2P3/2 → 2XJ″) = (31 ± 8) Å2. For HD: Q12 = (42 ± 5) Å2; Q21 = (27 ± 4) Å2; Q1X = (47 ± 13) Å2; Q2X = (38 ± 10) Å2. For D2: Q12 = (42 ± 5) Å2; Q21 = (27 ± 4) Å2; Q1X = (28 ± 8) Å2; Q2X = (21 ± 7) Å2. For N2: Q12 = (107 ± 15) Å2; Q21 = (70 ± 10) Å2; Q1X = (128 ± 44) Å2; Q2X = (126 ± 33) Å2. For CH4: Q12 = (38 ± 6) Å2; Q21 = (24 ± 3) Å2; Q1X = (129 ± 41) Å2; Q2X = (114 ± 37) Å2. For CD4: Q12 = (52 ± 7) Å2; Q21 = (34 ± 5) Å2; Q1X = (82 ± 30) Å2; Q2X = (76 ± 22) Å2. An analysis of these results suggests the possibility of resonances with various molecular rotational and vibrational transitions.

scholarly journals Optische Anregung beim Ladungsaustausch von Ne+-Ionen mit den Molekülen N2, O2 und CO2 bei Energien unterhalb 250 eVolt

1968 ◽  
Vol 23 (9) ◽  
pp. 1386-1391
Author(s):  
H. Schlumbohm
Keyword(s):  
Charge Transfer ◽  
Cross Sections ◽  
Light Emission ◽  
Optical Excitation ◽  
Ground Level ◽  
Molecular Ions ◽  
Vibrational Bands ◽  
The Cross ◽  
Threshold Energies ◽  
Franck Condon

An experimental investigation of the light emission being excited by charge transfer collisions between ground level Ne+-ions and molecules of N2, O2, and CO2 at collisional energies up to 250 eVolts has shown optical excitation of the molecular ions being formed. The spectral scannings show the main system of N2+ and mainly the first negative system of O2+. Thus N2+ is formed in the excited B2Σu+-levels and O2+ in the b4Σg-- and to a smaller amount in the A2Πu-levels. Both reactions approach energy resonance within 1 to 3 eVolts as far as it is possible following the Franck-Condon principle. The spectral scanniings measured with CO2 as the target molecule indicate that at almost equal rates CO2+ is formed in the Ã2IIu-levels and by dissociative charge transfer CO+ in the upper A2II-levels of the observed comet-tail bands. The energy balance of this dissociative reaction is endothermic within 2,1 eVolts. — The cross sections for the excitation of definite vibrational bands of CO2+, CO+, and N2+ show threshold energies of several eVolts. After a primary increase the cross sections remain constant over the total energy range up to 250 eVolts. Only for the excitation of N2+ a broad maximum between 20 and 30 eVolts was found.

SENSITIZED FLUORESCENCE IN VAPORS OF ALKALI METALS: VII. ENERGY TRANSFER IN RUBIDIUM–CESIUM COLLISIONS

1966 ◽  
Vol 44 (4) ◽  
pp. 741-751 ◽  
Author(s):  
M. Czajkowski ◽  
D. A. McGillis ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Alkali Metals ◽  
Dominant Role ◽  
Inelastic Collisions ◽  
Cesium Vapor ◽  
Rubidium Vapor ◽  
Total Cross Sections ◽  
Sensitized Fluorescence ◽  
Rubidium Atoms ◽  
Transfer Processes

Sensitized fluorescence in cesium vapor induced by collisions with excited rubidium atoms was investigated in order to determine the total cross sections for inelastic collisions between excited rubidium atoms and cesium atoms in their ground states. The partial pressure of the rubidium vapor in the Rb–Cs mixture was kept below 2 × 10−5 mm Hg in order to eliminate effects due to the trapping of the Rb resonance radiation. The collision cross sections for the various excitation transfer processes are as follows: Q12′(Rb 5 2P1/2 → Cs 6 2P3/2) = 1.5 Å2; Q11′(Rb 5 2P1/2 → Cs 6 2P1/2) = 0.5 Å2; Q22′(Rb 5 2P3/2 → Cs 6 2P3/2) = 0.9 Å2; Q21′(Rb 5 2P3/2 → Cs 6 2P1/2) = 0.3 Å2. The fact that the cross sections are considerably smaller than those for collisions between similar atoms indicates that the Rb–Cs interactions probably involve van der Waals' forces with a much shorter range than exchange forces, which play a dominant role in Rb–Rb or Cs–Cs collisions.

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