Deactivation of HF(ν = 1,2) by fluoroethylenes

1978 ◽  
Vol 56 (3) ◽  
pp. 387-391 ◽  
Author(s):  
S. J. Arnold ◽  
G. H. Kimbell
Keyword(s):  
Cross Sections ◽  
Rate Constants ◽  
Hydrogen Atoms ◽  
Flow Tube ◽  
Discharge Flow ◽  
Deactivation Rate ◽  
The Cross

A discharge flow tube technique has been used to measure the deactivation of HF(ν = 1,2). Effective vibrational deactivation rate constants for HF(ν = 1,2) relaxed by C2H4, C2H3F, 1,1-C2H2F2, cis-1,2-C2H2F2, trans-1,2-C2H2F, C2HF3, and C2F4 have been determined. For HF(ν = 1) the values of the rate constants range from 4.9 × 104 s−1 Torr−1 for C2H4 to 3.5 × 103 s−1 Torr−1 for C2F4 and for HF(ν = 2) from 1.3 × 105 s−1 Torr−1 to 8.8 × 103 s−1 Torr−1. The cross sections for the deactivation of HF(ν = 1) and HF(ν = 2) by C2H4 and the fluoroethylenes are observed to scale linearly with the number of hydrogen atoms.

Importance of coupling for inelastic collisions between protons and hydrogen atoms

1965 ◽  
Vol 283 (1392) ◽  
pp. 100-114 ◽  
Keyword(s):  
Cross Sections ◽  
Intermediate State ◽  
Relative Velocity ◽  
Inelastic Collisions ◽  
Hydrogen Atoms ◽  
Resonance Reactions ◽  
The Cross ◽  
Good Agreement

The importance of coupling for fast collisions between protons and hydrogen atoms is examined with the two-centred expansion in atomic eigenfunctions proposed by Bates (1958 a ). Cross-sections are evaluated for reactions H + + H (I s ) → H(I s ) + H + , H + + H( I s ) → H(2 s ) + H + , and H + + H(l a ) → H + + H(2 s ). The effect of a single intermediate state, either I s or 2 s , is considered. For the non-resonance processes, it is found that the cross-sections may be substantially increased by passage through intermediate state for incident energies less than about 10 keV, tending towards equality with decrease in relative velocity. Results obtained for the symmetrical resonance reactions are in good agreement with the two-state solutions of McCarroll (1961).

Comparison of the cross-sections and thermal rate constants for the reactions of C(3PJ) atoms with O2 and NO

2000 ◽  
Vol 2 (13) ◽  
pp. 2873-2881 ◽  
Author(s):  
Wolf D. Geppert ◽  
Denis Reignier ◽  
Thierry Stoecklin ◽  
Christian Naulin ◽  
Michel Costes ◽  
...  
Keyword(s):  
Cross Sections ◽  
Rate Constants ◽  
Thermal Rate Constants ◽  
The Cross

The determination of cross sections for quenching of resonance radiation of metal atoms III. Results for thallium

1968 ◽  
Vol 303 (1475) ◽  
pp. 467-475 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Cross Section ◽  
Cross Sections ◽  
Rate Constants ◽  
Resonance Radiation ◽  
Metal Atoms ◽  
The Cross

The intensity of fluorescence of thallium has been measured in hydrogen-oxygen flames diluted with each of the gases, argon, helium, nitrogen and carbon dioxide and the measurements used to obtain the following values for the quenching cross section (Å 2 ) for the 7 s 2 S ½ state of thallium σ 2 H 2 = 0.03, σ 2 O 2 = 13.2 ± 1.5, σ 2 N 2 = 6.4 ± 0.2, σ 2 H 2 O = 1.75 ± 0.2, σ 2 CO = 13.6 ± 0.8, σ 2 CO 2 = 32.5 ± 1.5, σ 2 Ar ≤ 0.1, σ 2 He ≤ 0.12. These values for the cross sections have been used to re-calculate the rate constants of the reactions, Tl + H + X → H X + Tl*, where X = H, OH, Cl or Br, from the data obtained by Phillips & Sugden (1961). The re-calculated values are lower than the original ones by a factor of 2.2.

Spin-change cross-sections

1961 ◽  
Vol 262 (1308) ◽  
pp. 132-135 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Change Process ◽  
Change Processes ◽  
Hydrogen Atoms ◽  
Atomic Systems ◽  
The Cross

A quantal formulation of spin-change processes in collisions of atomic systems is presented. The cross-section for the spin-change process in the collision of two hydrogen atoms is computed for temperatures up to 10000°K and the results given in a table.

The 1 s -2 s excitation of hydrogen atoms by proton impact

1960 ◽  
Vol 258 (1293) ◽  
pp. 237-244 ◽  
Keyword(s):  
Interaction Energy ◽  
Cross Sections ◽  
Impact Excitation ◽  
Hydrogen Atoms ◽  
Third Order ◽  
Proton Impact ◽  
The Third ◽  
Intermediate States ◽  
The Cross ◽  
Approximation Calculation

It is shown that the cross-sections given by the customary second Born approximation are not reliable because of the neglect of a large term of the fourth order in the interaction energy. The expression for the cross-section obtained by including only terms to the third order in the interaction energy is employed to calculate the cross-sections for the proton impact excitation of the 2 s state of atomic hydrogen, allowance being made for distortion and polarization due to the 1 s , 2 s and 2 p 0.±1 intermediate states. When polarization is ignored by neglecting all terms involving the 2 p states, excellent agreement is found with the distortion approximation calculation of Bates.

The cross sections for different channels in heavy ion nuclear reactions

1971 ◽  
Vol 32 (1) ◽  
pp. 7-9 ◽  
Author(s):  
J. Galin ◽  
D. Guerreau ◽  
M. Lefort ◽  
X. Tarrago
Keyword(s):  
Cross Sections ◽  
Nuclear Reactions ◽  
Heavy Ion ◽  
The Cross
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