Thermal rate constants for electron attachment to NO: An example of endothermic attachment.

Rate constants for dissociative electron attachment to NO yielding O have been measured as a function of temperature from 400 K to 1000 K. Detailed modeling of kinetics was needed to derive the rate constants at temperatures of 700 K and higher. In the 400 K-600 K range, upper limits are given.

Thermal activation of methane by MgO: temperature dependent kinetics, reactive molecular dynamics simulations and statistical modeling.

The kinetics of MgO+ + CH4 was studied experimentally using the variable ion source, temperature adjustable selected ion flow tube (VISTA-SIFT) apparatus from 300-600 K and computationally by running and analyzing reactive atomistic simulations. Rate coefficients and product branching fractions were determined as a function of temperature. The reaction proceeded with a rate of k = 5.

Reactions of C + Cl, Br, and I-A comparison of theory and experiment.

Rate constants for the reactions of C + Cl, Br, and I were measured at 300 K using the variable electron and neutral density electron attachment mass spectrometry technique in a flowing afterglow Langmuir probe apparatus. Upper bounds of <10 cm s were found for the reaction of C with Br and I, and a rate constant of 4.2 ± 1.

Thermal Kinetics of Al + O ( = 2-30): Measurable Reactivity of Al.

Mass-selected aluminum anion clusters, Al, were reacted with O. Rate constants (300 K) for 2 < < 30 and product branching fractions for 2 < < 17 are reported. Reactivity is strongly anticorrelated to Al electron binding energy (EBE).

Mutual neutralization of H and D with the atomic halide anions Cl,Br, and I.

Mutual neutralization (MN) rate constants k for the reactions of H and D with the atomic halide anions Cl, Br, and I were measured using the variable electron and neutral density attachment mass spectrometry technique in a flowing afterglow Langmuir probe apparatus. At 300 K, the rate constants for each reaction studied are on the order of 10 cm s. A trend for the rate constants of the systems in this work, kCl View Article and Find Full Text PDF

Reactivity of Fe(CO) + O: oxidation of CO by O at an isolated metal atom.

The kinetics of Fe(CO) + O are measured under thermal conditions from 300-600 K using a selected-ion flow tube apparatus. Both the bare metal and n = 2 cations are inert to reaction over this temperature range, but Fe(CO) reacts rapidly (k = 3.2 ± 0.

Reactivity from excited state (4)FeO(+) + CO sampled through reaction of ground state (4)FeCO(+) + N2O.

The kinetics of the FeCO(+) + N2O reaction have been studied at thermal energies (300-600 K) using a variable temperature selected ion flow tube apparatus. Rate constants and product branching fractions are reported. The reaction is modestly inefficient, proceeding with a rate constant of 6.

High-repetition-rate laser ignition of fuel-air mixtures.

A laser-ignition (LI) method is presented that utilizes a high-repetition-rate (HRR) nanosecond laser to reduce minimal ignition energies of individual pulses by ∼10 times while maintaining comparable total energies. The most common LI employs a single nanosecond-laser pulse with energies on the order of tens of millijoules to ignite combustible gaseous mixtures. Because of the requirements of high energy per pulse, fiber coupling of traditional LI systems is difficult to implement in real-world systems with limited optical access.

Reduction of breakdown threshold by metal nanoparticle seeding in a DC microdischarge.

Significant reduction of the breakdown threshold in a DC microdischarge via seeding metal nanoparticles has been demonstrated. Compared to standard Paschen curves in dry air, reductions in the breakdown voltage of 5% to 25% were obtained for PD values (the product of pressure and electrode gap distance) ranging from 20 to 40 Torr-cm by seeding aluminum and iron nanoparticles with mean sizes of 75 nm and 80 nm, respectively. No secondary energy source was required to achieve this breakdown threshold reduction.

Kinetics and product branching fractions of reactions between a cation and a radical: Ar(+) + CH3 and O2(+) + CH3.

A novel technique is described for the measurement of rate constants and product branching fractions of thermal reactions between cation and radical species. The technique is a variant of the variable electron and neutral density attachment mass spectrometry (VENDAMS) method, employing a flowing afterglow-Langmuir probe apparatus. A radical species is produced in situ via dissociative electron attachment to a neutral precursor; this allows for a quantitative derivation of the radical concentration and, as a result, a quantitative determination of rate constants.

Flame temperature measurements by radar resonance-enhanced multiphoton ionization of molecular oxygen.

Here we report nonintrusive local rotational temperature measurements of molecular oxygen, based on coherent microwave scattering (radar) from resonance-enhanced multiphoton ionization (REMPI) in room air and hydrogen/air flames. Analyses of the rotational line strengths of the two-photon molecular oxygen C(3)Π(v=2)←X(3)Σ(v'=0) transition have been used to determine the hyperfine rotational state distribution of the ground X(3)Σ(v'=0) state. Rotationally resolved 2+1 REMPI spectra of the molecular oxygen C(3)Π(v=2)←X(3)Σ(v'=0) transition at different temperatures were obtained experimentally by radar REMPI.