2 edition of Total and dissociative photoionization cross sections of N from threshold to 107 eV found in the catalog.
Total and dissociative photoionization cross sections of N from threshold to 107 eV
1986 by National Aeronautics and Space Administration, National Technical Information Center, distributor in [Washington DC, Springfield, Va .
Written in English
|Statement||James A.R. Samson ... [et al.].|
|Series||NASA contractor report -- NASA CR-180172.|
|Contributions||Samson, James A. R., United States. National Aeronautics and Space Administration.|
|The Physical Object|
These changes are caused by different ionization cross-sections shown in Fig. 2 at the two different photo-excitation energies. These differences were not taken into consideration so far. The photoionization cross-section of Fe 3d orbitals almost doubles at eV excitation energy compared with the cross-section at eV.
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The absolute cross sections for the production of N and N 2 have been measured from the dissociative ionization threshold to Å.
In addition, the absolute photoabsorption and photoionization cross sections are tabulated between and Å. The ionization efficiencies are also given at several discrete wavelengths between and by: Evidence for dissociative double photoionization with excitation has been found.
Relative partial emission cross sections for N I and N II fluorescence have been recorded as a function of the exciting-photon energy.
g fluorescence in N 2 2 close to its threshold. Evidence for dissociative double photoionization with excitation has Cited by: Abstract. Dissociative photoionization of N 2 is studied with synchrotron radiation in the eV photon energy range. Branching ratios between the different dissociation limits are measured from coincidence time of flight ion spectra threshold photoelectron-photoion coincidence recorded for state-selected N 2 parent ions.
In this energy range, N 2 molecular ions are observed to Cited by: The total photoionization cross-sections for all six alkanes of the present study and those for cyclohexane reported previously rise monotonically above threshold in a quasi-linear fashion in agreement with qualitative expectations discussed by Koizumi.
Fig. 2 shows absolute photoionization cross-sections for methane for photon energies from to eV, using acetylene as the. Photoionization cross sections for the production of the doubly charged ion N 2 from N 2 have been measured by means of synchrotron radiation in the photon energy range from 50 to eV.
The appearance energy for N 2 has been determined as ± eV, i. about eV higher than the spectroscopic dissociation limit leading to the. For radicals with higher internal energy, dissociative ionization is the dominant process, and for internal energies of eV, we find a total cross-section (photoionization plus dissociative ionization) of ± Mb.
The results are discussed relative to the recently reported photoionization cross-section of phenol. We note that at energies around eV, the small rise in the cross-section is due to double photoionization with a threshold value of about 79 eV. The maximum contribution is at about eV and comprises about 4 of the total cross-section.
The dissociative photoionization of CF 3 Cl was investigated using threshold photoelectron photoion coincidence (TPEPICO) imaging in the energy range of eV. The coincident time-of-flight mass spectra and three-dimensional time-sliced images of the CF 2 Cl fragment were recorded at a few specific photon energies.
Two fragmentation pathways were observed that led to the breakage. Samson et al. measured both non-dissociative and dissociative photoionization cross sections of N 2 from threshold to Å. The measurements were extended down to Å by Stolte et al.
For photon wavelengths shortward of Å, Stolte et al. provided power law expressions for the cross section. Cross section data are compiled from the literature for electron collisions with oxides of nitrogen (N x O y) molecules: the species nitric oxide (NO), nitrous oxide (N 2 O), and nitrogen dioxide (NO 2) are explicitly sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states.
threshold photoelectron spectrum up to the dissociation threshold, and FranckCondon simulations identify the O C O bend mode, in particular in combination with the C O stretch mode, to be active.
The DMC ionization energy was determined to be ± eV. The rst dissociative photoionization product, CH 2 OHdominates the breakdown. theoretical MCDF energy of 2 p-subshell excited resonances in the single- and double-photoionization cross sections of Si in the eV photon energy range. Photodissociation and Dissociative Photoionization Mass Spectrometry of Proteins and Noncovalent ProteinLigand Complexes Dr.
Francis Canon, Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif-sur-Yvette (France). The present partial photoionization cross-sections were obtained by the use of Eq.
using the total absorption cross-section reported by Au and results are shown in Fig. 2 in comparison with those of Au and Brion, with the numerical values in Table should be noted that Au and Brion used the ionization yield of unity above eV (even in the energy region that dissociative.
Table 7 is a list of our recommended cross sections from to eV compared to those suggested by Samson Haddad (). The cross sections for the photoionization of H 2 may be represented analytically by where x E(eV) and s We do not attempt to reproduce the structures near threshold introduced by the presence of.
This set of absolute total photoionization cross-sections have been combined with photoelectron intensity branching ratios for the X ˜, A ˜, B ˜ and C ˜ states from threshold to eV reported graphically by Holland et al.
(Hol 99) to provide an alternative source of partial cross-sections, which we have compared with those based on. Absolute photoionization cross-sections for the rare gases have been measured from threshold to eV with an accuracy of 61 to 3 and are presented in both tabular and graphical form.
Photoionization cross sections for the production of the doubly charged ion N 2 from N 2 have been measured by means of synchrotron radiation in the photon energy range from 50toeV. The appearance energy for N 2 has been determined as ±eV, i.about eV higher than the spectroscopic dissociation limit leading to the charge asymmetric dissociation channel N2(P2)N.
The theoretical photoionization cross sections of solid gold are compared with the experimental values of both ideal gas and solid phase.
The results show that the suggested method is reliable and would open a new way to calculate the photoionization cross sections of complex molecules, clusters, and solid system. 2 Photoionization Cross. Dissociative photoionization and threshold photoelectron spectra of polycyclic aromatic hydrocarbon fragments: an imaging photoelectron photoion coincidence (iPEPICO) study of four substituted benzene radical cations.
West B(1), Sit A, Bodi A, Hemberger P, Mayer PM. Abstract. A compilation of data from various works on absolute partial cross-sections of triatomic molecules (H 2 O, CO 2, N 2 O, NO 2, H 2 S) and photoionization cross-sections of SO 2 and ozone have been studied by drawing conclusions from the data obtained.
Absolute partial cross-sections of ions by photoionization mass spectrometry and partial cross-section near K-edge are measured. A photoionization cross-section calculation for atomic scandium, which has the LS coupled ground-state configuration ([Mg] 3p63d4s2) [2D] is performed.
Request PDF | Dissociative double photoionization of N-2 using synchrotron radiation: Appearance energy of the N2 dication | Photoionization cross sections for the production of the doubly. Calculated near-threshold photoionization cross sections for (a) Ne, (b) Na 1, (c) Mg 2 1, (d) Al 3 1, (e) Si 4 1, and (f) P 5 1.
Note that the full height of the Al 3 1 resonance peak is. Abstract. The electron emission is one of the most efficient decay mechanisms for atoms or molecules excited above the ionization threshold.
This makes the knowledge of reliable photoionization cross sections very valuable in a variety of fields. Their importance has grown also for the development of the laser sources and of the synchrotron. Abstract: Partial and total photoionization cross sections of iron-peak elements are important for the determination of abundances in late-type stars and nebular objects.
We have investigated photoionization of neutral chromium from the ground and excited states in the low energy region from the rst ionization threshold at eV to 30 eV. Spectroscopy above the ionization threshold: Dissociative recombination of the ground vibrational level of N 2 of the calculation of total and partial DR cross sections and rate constants for N 2 over both major and minor dissociative the total number of possible dissociative states to 64 with 12 possible symmetries: 1,3 1,3 g,u, 1,3.
Energy-dependent evaluated photon interaction cross sections and related parameters are presented for elements H through Cf (Z 1 to 98). Data are given over the energy range from keV to MeV.
The related parameters include form factors and average energy deposits per. At eV, the photoionization cross sections for the phenyl radical averaged over product channels were found to be and Mb, respectively, with very little eect seen from the range of internal excitation produced at the two photolysis wavelengths.
Cross section in photoemission. The photoemission is a useful experimental method for the determination and the study of the electronic states. Sometimes the small amount of deposited material over a surface has a weak contribution to the photoemission spectra, which makes its identification very knowledge of the cross section of a material can help to detect thin layers or 1D.
In recent works  we have studied dissociative photoionization of H 2 and D 2 in the eV photon energy range. The theoretical method makes use of B-spline functions to represent both the electronic and nuclear wave functions, and includes consistently the interference between the various ionization and dissociation channels.
Introduction. We provide a set of tools to calculate photoionization, photodissociation, and photodissociative ionization rate coefficients and the associated photon energy-weighted excess energies of the various photo products. The program is based on two earlier publications: Solar Photo Rate Coefficients (Huebner and Carpenter, ) and Solar Photo Rates for Planetary Atmospheres.
Authors: Kelly, H P Publication Date: Sun Jul 15 EDT Research Org. : Univ. of Virginia, Charlottesville OSTI Identifier: NSA Number.
The total ionization cross sections for H 2 H 2N 2 N 2CDand CO from the modified BEB formula are compared to available experimental data. The theory is in good agreement with experimental data on H 2 H 2N 2 N 2and CDbut the experimental data by Belic et al.
on N 2 N 2and CO are lower than the theory. In the measured energy ranges of eV for CHT and eV for Tol, only the hydrogen atom loss channels open up, le Dissociative Photoionization of the C 7 H 8 Isomers Cycloheptatriene and Toluene: Looking at Two Sides of the Same Coin Simultaneously.
Ionization from a valence t 2 orbital shows overlapping shape resonances close to threshold that couple to the same total symmetry, leading to striking changes in the photoelectron angular distributions when viewed capable of accessing the dissociative photoionization dynamics of CF 4.
cross sections and asymmetry parameters were reported. A eV UV pump pulse launches a dissociative wave packet on excited states of both molecules and the ensuing dynamics are probed via photoionization using a eV probe pulse.
Total PI cross-sections in length form for the ground state of Ca iv as a function of photon energy ranging from eV corresponding to 3s 2 3p 4 3 P 2 threshold to eV associated with the 3s 2 3p 4 3 P 0 threshold of Ca v.
Consequently, the cross-section for photo-ionization tends to zero as approaches unity from below. We have retained the factor involving in Equation () because it makes clear that the photoelectrons are emitted preferentially in the directions, and.
The band maxima yield the vertical IE for these two molecules: ± eV and ± eV, respectively, while the best estimate of the adiabatic IE for DHF is ± eV. View Show abstract. Cross section. Not every interaction between a photon and an atom, or molecule, will result in photoionization.
The probability of photoionization is related to the photoionization cross section of the species, which depends on the energy of the photon (proportional to its wavenumber) and the species being considered.
In the case of molecules, the photoionization cross-section can be estimated.followed by the ionization ~threshold ; eV) of an inner-subshell 2p electron. Resonance structure due to 2p excitation in the 2p6 3s3p 3P metastable state was also observed with its contribution to the total cross section not exceeding 3%.
Calculation of the 2p photoionization continuum cross section .For radicals with higher internal energy, dissociative ionization is the dominant process, and for internal energies of ~ - eV, we find a total cross section (photoionization plus.