Excited Hydrogen

Vibrationally Excited Hydrogen.—Systems involving hydrogen occupy a special place in the hearts and minds of theoretically inclined kineticists, since they offer the best opportunity of correlating experimentally determined data with results from truly ab initio calculations. This is, of course, especially true of the Hs system and its isotopic variants. ° Furthermore, because the vibrational level spacing in Hi is unusually wide, dramatic changes in kinetic behaviour might be anticipated for even quite low levels of excitation. 

To excite Hi vibrationally by photochemical means, the Raman effect must be used. Although the stimulated Raman process has been used for this purpose in studies of vibrational energy transfer from Hi (and Di) to a variety of collision partners, ° and for an investigation of the effect of vibrational excitation on the molecular isotope exchange reaction,  

When Hi, either pure or diluted in He or Ar, is passed through the cavity of a 

Audibeit, C. Joffrin, and J. Ducuing, J. Chem. Phys., 1974, 61, 43S7, and references therein. 

Recently, Gershenzon and Rozenshtein have reported the results of a similar study on D 4- Dj (e = 1), although in their experiments [D] was determined by titration with NOa, and [Da( = 1)] was estimated by observing i.r. emission from CO2 which was added just upstream of an i.r. detector and was excited by vibrational-vibrational (V-V) energy transfer from Da. Their results are also given in Table 2. 

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C07-0126. The series of emission lines that results from excited hydrogen atoms undergoing transitions to the n — 3 level Is called the Paschen series. Calculate the energies of the first five lines In this series of transitions, and draw an energy level diagram that shows them to scale. 

N. Mataga and Y. Kaifu, Intermolecular proton transfer in the excited hydrogen-bonded complex in nonpolar solvent and fluorescence quenching due to hydrogen bonding, J. Phys. Chem. 36, 2804-2805 (1962). 

Figure 1.2. An image produced by exciting hydrogen gas and separating the outgoing light with a prism, reprinted from [Her. Fig. 1. p. 5]. Specifically, this is the emission spectrum of the hydrogen atom in the visible and near ultraviolet region. The label marks the position of the limit of the series of wavelengths.

FIGURE 5.6 (a) The visible line spectrum of energetically excited sodium atoms consists of a closely spaced pair of yellow lines, (b) The visible line spectrum of excited hydrogen atoms consists of four lines, from indigo at 410 nm to red at 656 nm. 

Excited hydrogen atoms give off a bluish light excited neon atoms emit orange light. 

Pibel, C.D. and Moore, C.B. (1990). Molecular angular momentum reorientation of electronically excited hydrogen (B1E+), J. Chem. 

This effect has been thoroughly investigated in numerous experiments that result in the following conclusion the interaction of the excited hydrogen atom with a metal surface has a specific nature and only phenomenologically can be... 

Vibrationally excited hydrogen (v = 1) cannot be produced by direct photon absorption, but may be produced by coherent Raman excitation... 

As shown in Fig. 5.1, since excited hydrogen atoms can be produced by dissociation of hydrogen molecules and molecular ions, the hydrogen molecules can affect emission from the hydrogen atoms. Therefore, by investigating emission from the hydrogen atoms, we can study hydrogen molecule behav-... 

We perform numerical modeling of atomic processes in various real plasmas including LHD fuel-pellet ablation and short-pulse laser interaction plasmas [21], We are developing a mixed quantum-classical code to study excited hydrogen atom formation in neutrals of back scattered protons at wall surfaces. 

Figure 4.4 Schematic Diagram of Light Emission from an Excited Hydrogen Atom...

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