Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Sensitized fluorescence in crossed atomic beams: Hg(6 $sup 3$P$sub 0$,$sub 2$)+Tl(6 $sup 2$P$sub 1$/$sub 2$)

Lambert C.-H. Loh, Charlotte M. Sholeen, Ronald R. Herm, D. D. Parrish

Published Sep 1, 1975• 0 citations
OpenAlex

Abstract

A velocity selected Tl beam has been crossed by an electron-bombarded Hg beam which contains a small percentage of the Hg(6 $sup 3$P) metastable levels (an approximate 5:1 ratio of $sup 3$P$sub 2$:$sup 3$P$sub 0$). By means of an interference filter--photomultiplier combination beneath the collision zone, the cross section for excitation of the 5350 A (7 $sup 2$S$sub 1$/$sub 2$ $Yields$ 6 $sup 2$P$sub 3$/$sub 2$)Tl fluorescence has been determined to increase monotonically with decreasing relative collision speed, g, approximately as g$sup -$/subs/ for s=2.0plus-or-minus0.5. Implications of these results for the sensitized fluorescence phenomenon in vapor mixtures of metallic elements are briefly discussed.

Related papers

Sensitized fluorescence in crossed atomic beams: Hg(6 3P0,2)+Tl(6 2P1/2)

Lambert C.-H. Loh, Charlotte M. Sholeen, Ronald R. Herm +1 more

A velocity selected Tl beam has been crossed by an electron-bombarded Hg beam which contains a small percentage of the Hg(6 3P) metastable levels (an approximate 5:1 ratio of 3P2:3P0). By means of an interference filter–photomultiplier combination beneath the collision zone, the cross section for excitation of the 5350 Å (7 2S1/2 → 6 2P3/2)Tl fluorescence has been determined to increase monotonically with decreasing relative collision speed, g, approximately as g−s for s=2.0±0.5. Implications of these results for the sensitized fluorescence phenomenon in vapor mixtures of metallic elements are briefly discussed.

The Journal of Chemical Physics•Sep 1, 1975•4 citations

Sensitized fluorescence in thallium induced in collisions with Hg(63P1) atoms

Murray K Wade, M. Czajkowski, L. Krause

The transfer of excitation from excited mercury atoms to ground-state thallium atoms was investigated using techniques of sensitized fluorescence. A Hg–Tl vapor mixture contained in a quartz cell was irradiated with Hg 2537 Å resonance radiation which caused the mercury atoms to become excited to the 63P1, state. Subsequent collisions between the Hg(63P1) and Tl(62P1/2) atoms resulted in the population of the 82S1/2, 62D, and 72S1/2 thallium states, whose decay gave rise to sensitized fluorescence of wavelengths 3231, 3520, 3776, and 5352 Å. Intensity measurements on the sensitized fluorescence and on the Hg 2537 Å resonance fluorescence, observed at right angles to the direction of excitation, yielded cross sections of 3.0, 0.3, and 0.05 Å2 for collisional excitation transfer from Hg(63P1) to the 82S1/2, 62D, and 72S1/2 states in thallium, respectively. The results are fully consistent with previously determined cross sections for excitation transfer in other binary metallic vapor systems.

Canadian Journal of Physics•Jul 1, 1978•10 citations

Effects of Added Gases on the Sensitized Fluorescence Spectrum of a Hg-Tl Mixture

Richard Allen Anderson, Robert H. McFarland

An investigation of the sensitized fluorescence of a mercury thallium mixture without and with the addition of argon and helium gases is discussed. Data taken without the addition of foreign gases are used to extend the theory of Frish and Karaulinya to a mercury thallium mixture. Relative collision cross sections for the excitation of the thallium energy states, $9^{2}S_{\frac{1}{2}}$, $7^{2}D_{\frac{5}{2},\frac{3}{2}}$, $8^{2}S_{\frac{1}{2}}$, $6^{2}D_{\frac{5}{2}}$, and $6^{2}D_{\frac{3}{2}}$ were calculated for mercury thallium collisions. Data taken with the addition of argon and helium gases are given to indicate the variation of the intensity of the thallium lines as a function of argon and helium gas pressures at one constant thallium and three mercury temperatures. The explanation of the results depends on the role of mercury $6^{3}P_{1}$ excited atoms, metastable atoms, and mercury molecules in collision with thallium atoms for energy exchange, and also requires the use of Winans' partial selection rule and other generally accepted ideas concerning energy transfer, emission, and absorption.

Physical Review•Jul 15, 1960•9 citations

SENSITIZED FLUORESCENCE IN VAPORS OF ALKALI METALS: I. ENERGY TRANSFER IN POTASSIUM–POTASSIUM COLLISIONS

G. D. Chapman, L. Krause, I. H. Brockman

Sensitized fluorescence in potassium vapor at pressures between 10−5 mm Hg and 10−1 mm Hg was investigated to determine the cross sections for collisions of the second kind between unexcited and excited potassium atoms. An idealized fluorescence tube was used in the experiment and the fluorescent light was analyzed with a photoelectric recording spectrometer. The collision cross sections at low vapor pressures, where imprisonment of radiation is absent, are identical for both the 42P1/2 → 42P3/2 and 42P1/2 ← 42P3/2 transitions and equal 6.6 × 10−12 cm2 at 2 × 10−4 mm Hg. The experimental results are interpreted on the basis of new selection rules for sensitized fluorescence.

Canadian Journal of Physics•Mar 1, 1964•12 citations

Sensitized fluorescence in vapors of alkali metals. X. Energy transfer in sodium–sodium collisions

John M. Pitre, L. Krause

The total cross sections for 3 2P1/2–3 2P3/2 mixing collisions between excited and unexcited sodium atoms have been determined in a series of sensitized fluorescence experiments with pure sodium vapor at pressures in the range 0–1.6 × 10−5 mm Hg. The cross section Q2(3 2P1/2 ← 3 2P3/2) was found to be 283 Å2 ± 10%. The cross section Q1(3 2P1/2 → 3 2P3/2) = 532 Å2 was obtained from Q2 through the application of the principle of detailed balancing.

Canadian Journal of Physics•Jan 15, 1968•28 citations

Sensitized Fluorescence in Sodium Induced in Collisions with Hg(63P1) Atoms

M. Czajkowski, George M. Skardis, L. Krause

Collisional transfer of excitation from mercury to sodium was investigated using methods of sensitized fluorescence. A mixture of mercury and sodium vapors at low pressure was irradiated with Hg 2537 Å resonance radiation, producing a population of Hg(63P1) atoms whose inelastic collisions with ground-state sodium atoms resulted in a transfer of excitation energy to close-lying S, P, and D states in sodium. The subsequent decay of these states manifested itself in the emission of a sensitized fluorescent spectrum. Absolute intensity measurements on the components of the spectrum yielded 21 cross sections whose magnitudes range from 0.02 to 38.5 Å2 and which exhibit a pronounced resonance with ΔE, the energy defect between Hg (63P1) and the appropriate level in sodium.

Canadian Journal of Physics•Feb 1, 1973•12 citations
Sensitized fluorescence in crossed atomic beams: Hg(6 sup3sup 3sup3Psub0sub 0sub0,sub2sub 2sub2)+Tl(6 sup2sup 2sup2Psub1sub 1sub1/sub2sub 2sub2)
A velocity selected Tl beam has been crossed by an electron-bombarded Hg beam which contains a small percentage of the Hg(6 sup3sup 3sup3P) metastable levels (an approximate 5:1 ratio of sup3sup 3sup3Psub2sub 2sub2:sup3sup 3sup3Psub0sub 0sub0). By means of an interference filter--photomultiplier combination beneath the collision zone, the cross section for excitation of the 5350 A (7 sup2sup 2sup2Ssub1sub 1sub1/sub2sub 2sub2 YieldsYieldsYields 6 sup2sup 2sup2Psub3sub 3sub3/sub2sub 2sub2)Tl fluorescence has been determined to increase monotonically with decreasing relative collision speed, g, approximately as gsup−sup -sup−/subs/ for s=2.0plus-or-minus0.5. Implications of these results for the sensitized fluorescence phenomenon in vapor mixtures of metallic elements are briefly discussed.
A velocity selected Tl beam has been crossed by an electron-bombarded Hg beam which contains a small percentage of the Hg(6 3P) metastable levels (an approximate 5:1 ratio of 3P2:3P0). By means of an interference filter–photomultiplier combination beneath the collision zone, the cross section for excitation of the 5350 Å (7 2S1/2 → 6 2P3/2)Tl fluorescence has been determined to increase monotonically with decreasing relative collision speed, g, approximately as g−s for s=2.0±0.5. Implications of these results for the sensitized fluorescence phenomenon in vapor mixtures of metallic elements are briefly discussed.
The transfer of excitation from excited mercury atoms to ground-state thallium atoms was investigated using techniques of sensitized fluorescence. A Hg–Tl vapor mixture contained in a quartz cell was irradiated with Hg 2537 Å resonance radiation which caused the mercury atoms to become excited to the 63P1, state. Subsequent collisions between the Hg(63P1) and Tl(62P1/2) atoms resulted in the population of the 82S1/2, 62D, and 72S1/2 thallium states, whose decay gave rise to sensitized fluorescence of wavelengths 3231, 3520, 3776, and 5352 Å. Intensity measurements on the sensitized fluorescence and on the Hg 2537 Å resonance fluorescence, observed at right angles to the direction of excitation, yielded cross sections of 3.0, 0.3, and 0.05 Å2 for collisional excitation transfer from Hg(63P1) to the 82S1/2, 62D, and 72S1/2 states in thallium, respectively. The results are fully consistent with previously determined cross sections for excitation transfer in other binary metallic vapor systems.
An investigation of the sensitized fluorescence of a mercury thallium mixture without and with the addition of argon and helium gases is discussed. Data taken without the addition of foreign gases are used to extend the theory of Frish and Karaulinya to a mercury thallium mixture. Relative collision cross sections for the excitation of the thallium energy states, 92S129^{2}S_{\frac{1}{2}}92S21​​, 72D52,327^{2}D_{\frac{5}{2},\frac{3}{2}}72D25​,23​​, 82S128^{2}S_{\frac{1}{2}}82S21​​, 62D526^{2}D_{\frac{5}{2}}62D25​​, and 62D326^{2}D_{\frac{3}{2}}62D23​​ were calculated for mercury thallium collisions. Data taken with the addition of argon and helium gases are given to indicate the variation of the intensity of the thallium lines as a function of argon and helium gas pressures at one constant thallium and three mercury temperatures. The explanation of the results depends on the role of mercury 63P16^{3}P_{1}63P1​ excited atoms, metastable atoms, and mercury molecules in collision with thallium atoms for energy exchange, and also requires the use of Winans' partial selection rule and other generally accepted ideas concerning energy transfer, emission, and absorption.
Sensitized fluorescence in potassium vapor at pressures between 10−5 mm Hg and 10−1 mm Hg was investigated to determine the cross sections for collisions of the second kind between unexcited and excited potassium atoms. An idealized fluorescence tube was used in the experiment and the fluorescent light was analyzed with a photoelectric recording spectrometer. The collision cross sections at low vapor pressures, where imprisonment of radiation is absent, are identical for both the 42P1/2 → 42P3/2 and 42P1/2 ← 42P3/2 transitions and equal 6.6 × 10−12 cm2 at 2 × 10−4 mm Hg. The experimental results are interpreted on the basis of new selection rules for sensitized fluorescence.
Collisional transfer of excitation from mercury to sodium was investigated using methods of sensitized fluorescence. A mixture of mercury and sodium vapors at low pressure was irradiated with Hg 2537 Å resonance radiation, producing a population of Hg(63P1) atoms whose inelastic collisions with ground-state sodium atoms resulted in a transfer of excitation energy to close-lying S, P, and D states in sodium. The subsequent decay of these states manifested itself in the emission of a sensitized fluorescent spectrum. Absolute intensity measurements on the components of the spectrum yielded 21 cross sections whose magnitudes range from 0.02 to 38.5 Å2 and which exhibit a pronounced resonance with ΔE, the energy defect between Hg (63P1) and the appropriate level in sodium.