Rovibrationally resolved relative cross sections for electron impact excitation of

Laser probing of the electron-impact excited c(2p)3 umanifold of states in H2

“…Once these quantum numbers are determined, ro-vibrationally specific excitation functions of states within the c 3 u metastable manifold are extracted by monitoring the ion yield as a function of electron-impact energy. These measurements contrast with those of Ottinger and Rox [11] who used laser induced fluorescence, since the technique adopted here is not restricted to the specific angular momentum states which are coupled by fluorescence. Fischer et al [12] have also used a stepwise technique to study the relative population of magnetic substates in the electron-impact excitation of metastable neon.…”

“…Since only the lowest vibrational level of the X 1 + g ground state is populated in the target beam, these excitation cross-sections are state selective for both ground and metastable states. A similar technique has been employed by Ottinger and Rox [11], who obtained cross-sections for electron-impact excitation of c 3 u , v = 0-3 states by observing laser induced fluorescence as a function of electron-impact energy.…”

Energies, transition probabilities, predissociation rates, and lifetimes of the ${{\rm{H}}}_{2}$, HD, and ${{\rm{D}}}_{2}$ $c{}^{3}{{\rm{\Pi }}}_{u}^{-}$ state

“…The (v j , N j ) levels of the S + a g 3 and P c u 3 states are very close to each other. In particular, the N j levels of the P c u 3 (v=0) state are below those of the , S + a g state hydrogen molecules are typically prepared either by low energy electron excitation from the S + X g 1 state (Lichten and Wik 1978, Eyler and Pipkin 1981, Ottinger and Rox 1991, Ray and Lafyatis 1996 or by charge exchange of a molecular hydrogen ion beam with alkaline metal (such as Cs) vapor (Helm et al 1984, de Bruijin and Helm 1986, Koot et al 1989a, 1989b, Wouters et al 1996, 1997. The H 2 Pc u 3 metastable species was at one time (incorrectly) believed to be a spectral carrier for some diffuse interstellar band transitions (Herbig 1963).…”

“…, and P c u 3 states, have been almost exclusively measured by EEL spectroscopy (Khakoo and Trajmar 1986, Nishimura and Danjo 1986, Khakoo et al 1987, Khakoo and Segura 1994, Wrkich et al 2002. Other experimental investigations (Mason and Newell 1986, Ottinger and Rox 1991, Ajello and Shemansky 1993, Furlong and Newell 1995, Harries et al 2004 measured only the relative values of cross sections or excitation functions and require normalizations to certain standards to obtain absolute values. Theoretical calculations include those by Chung et al (1975), Lee et al (1993Lee et al ( , 1996, Stibbe and Tennyson (1998), Trevisan and Tennyson (2002), Laricchiuta et al (2004), da Costa et al (2005, and Taveira et al (2006).…”