... Electron Impact Ionization I April 1994 ... Quantitative Monitoring of Ammonia and Hydrazines: Absolute Cross Sections for Electron Impact Ionization ...

Jan 22, 2011 ... Title: Absolute Electron Impact Ionization Cross Sections for N₂O and NO from Threshold up to 1000 eV. Authors: Srivastava, S. ...

Jan 22, 2011 ... dc.title, Absolute Electron Impact Ionization Cross Sections for N₂O and NO from Threshold up to 1000 eV, en_US ...

Absolute excitation functions for excited fragments resulting from electron bombardment of H2O, NH3,

If we define Electron Impact Spectroscopy as that phase of inelastic electron scattering which deals with resolved (electron) spectra, then the subject is still far too large to be surveyed in a one-hour speech. If, however, attention is confined to the s...

Laboratory/. California. Institute of. Technology, under contract with the U.S. Airforce Office of. Scientific Research and the National Aeronautics and Space ...

The absolute cross sections for the single ionization of Ba sup + ions by electron impact have been measured as a function of incident electron energy over the electron energy range from below threshold (10.001 eV) to approximately 1000 eV. It is found th...

A combined experimental and theoretical study of 50 eV electron-impact ionization of helium is presented. The absolute coplanar triple differential cross sections (TDCS) are measured for 4 eV and 10 eV slow electrons for fixed scattering angles; -20 deg, ...

Absolute cross sections for the single ionization of Rb/sup +/ ions by electron impact have been measured as a function of electron energy from below threshold to approximately 2000 eV. Measurements were made in a crossed-beam facility having modulated beams. Numerous consistency checks were performed to evaluate ...

Absolute electron impact ionization cross-sections have been measured for the Neon-like Ar sup 8+ in the energy range from below the threshold for the metastable state to 2500 eV. No contribution of metastable states is observed. The results are well repr...

The absolute electron-impact optical emission cross sections of numerous vibrational bands of the second positive band system of the nitrogen molecule have been measured for electron impact energy from threshold up to 600 eV. From the optical data the app...

Absolute cross sections for simultaneous double ionization and excitation of Ba by electron impact have been measured in a crossed-beam experiment. The lines investigated are at 74.3, 58.7, and 55.5 nm. The vacuum-ultraviolet system was calibrated using a single-ionization chamber. Absolute cross sections were ...

The absolute cross sections for the single, double, triple and quadruple ionization of Cs exp + ions by electron impact have been measured from below their respective thresholds to approximately 5000 eV. This determination has been accomplshed using a cro...

The absolute cross sections for the double, triple, and quadruple ionization of Rb exp + ions by electron impact have been measured from below their respective thresholds to approximately 3000 eV. This determination has been accomplished using a crossed b...

A set of three computer programs is reported which allow for the deconvolution of overlapping molecular electronic state structure in electron energy-loss spectra, even in highly perturbed systems. This procedure enables extraction of absolute differentia...

We present a new method for measuring absolute total electron-impact ionization cross sections. The technique measures fractional loss rates from a magneto-optical trap due to electron-impact ionization. The method requires only relative measurements of the number of target atoms and therefore eliminates a major source of difficulty in ...

Electron-impact-ionization cross sections have been measured for the halogen atoms F, Cl, Br, and I from threshold to 200 eV. The absolute accuracy is +- 14%, except for F which is +- 20%. The halogen cross sections have shapes similar to those of the neighboring rare gases but are greater in magnitude. Simple semiclassical formulas of ...

A program has been undertaken to measure absolute electron-ionization cross sections for metals and other materials of low vapor pressure. Equipment necessary to make these measurements, ionizers, Knudsen cells, charged particle traps, and a large quadrup...

Doubly differential cross sections for single and multiple ionization of Ar have been measured for 500, 750, and 1000 eV electron impact. The cross sections were measured as a function of projectile energy loss and scattering angle. The energy loss range was 0-85% of the initial projectile energy and scattering angles were between {+-}22 deg. The data were ...

A method of absolute intensity measurement of intensive impulse fluxes has been described. Method and primary absolute detector device - photoionization quantometer - are based on fundamental cross sections of photoionization and ionization by electron impact. New soft X-ray optic elements - multilayer mirrors ...

Absolute total cross section (TCS) measurements of electron scattering from gaseous methanol and ethanol molecules are reported for impact energies from 60 to 500 eV, using the linear transmission method. The attenuation of intensity of a collimated electron beam through the target volume is used to determine the ...

device failure to be modeled as follows: Int2/tl=E./k(1/T-l/T,) where t I,2 =time to failure. E.= activation energy in electron volts. T = absolute temperature in Kelvin ...

Straub, H.C. et al. "Absolute partial cross sections for electron-impact ionization of H_2, N_2, and O_2 from threshold to 1000 eV," Phys. Rev. ...

Straub, H.C. et al. "Absolute partial cross sections for electron-impact ionization of H_2, N_2, and O_2 from threshold to 1000 eV," Phys. Rev. ...

Absolute cross sections were measured for the electron-impact dissociation of simple molecules using a novel fast beam technique with multicoincident detection of the dissociation fragments. Translational energy released in the dissociation and product ma...

Absolute cross sections for the single, double, triple, and quadruple ionization of Cs/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 5000 eV. These measurements have been made using a crossed beam facility operated in a pulsed beam mode. Numerous consistency checks were ...

The absolute cross sections for the double, triple, and quadruple ionization of Rb/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 3000 eV. This determination has been accomplished using a crossed-beam facility in which monoenergetic beams of ions and ...

We have conducted measurements of absolute differential cross sections for the excitation of hydrogen atoms to their n=3(3S+3P+3D) and 4(4S+4P+4D+4F) levels. A modulated, crossed-beam method was employed, and the impact energies were 40 and 60 eV. Comparison of our results with those of others is quite favorable.

We present absolute partial electron impact ionization cross sections for ethylene in the electron energy range between threshold and 1000 eV measured with a two sector field double focusing mass spectrometer. Ion kinetic energy distribution functions have been measured at all electron energies ...

We report absolute partial electron-impact ionization cross sections measured using a time-of-flight mass spectrometer with position-sensitive detection. The design and performance of the apparatus are presented. Two-dimensional plots combining information from time-of-flight and ion impact location on the detector demonstrate the ...

The absolute electron-impact ionization cross section of the metastable He(2s triplet S) state of helium has been measured by the application of a double-electron-beam technique. The ionization of the metastable He(2s singlet S) state of helium has also b...

Absolute cross sections for the excitation of the OI 3s (triplet S(0)) and 3s (quintet S(0)) states by electron impact on atomic oxygen have been measured for electron energies from threshold to 300 eV. Both cross sections are larger than the values predi...

Vacuum ultraviolet multiplets of C(I), C(II), and O(I) have been produced by electron impact on CO2. Absolute emission cross sections for these multiplets have been measured from threshold to 350 eV. The electrostatically focussed electron gun used in thi...

Absolute differential cross sections (DCS's) for electron-impact excitation of the lowest forty electronic levels in atomic neon have been determined for incident electron energies of 30 and 50 eV, for the four lowest levels at 25 eV, and two levels at 100 eV. The cross sections for these forty ...

like SAPOS in Germany. The conversion to absolute phase center models has already been achieved in several of these networks due to the improved performance ...

The absolute cross sections for the single, double, triple and quadruple ionization of Cs/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 5000 eV. This determination has been accomplshed using a crossed beam facility in which monoenergetic beams of ions and ...

Absolute electron impact ionization cross-sections have been measured for the Neon-like Ar/sup 8 +/ in the energy range from below the threshold for the metastable state to 2500 eV. No contribution of metastable states is observed. The results are well reproduced by the Distorted Wave Born Approximation. 12 refs., 1 fig.

Relative and absolute electron impact ionization cross sections were measured for species of three elements. The data include results on Au(+), Au(2+), Au(3+); Cr(+), Cr(2+); Fe(+), Fe(2+), Fe(3+). Total cross section results on the elements are also repo...

This paper reports absolute elastic differential scattering cross sections (DCSs) for electron impact on CO and N2 in the energy range 20-100 eV and angular range 20-120 deg. The results are obtained using a relative flow technique in which the DCS of CO is compared with that of He at each angle and energy and the DCS of N2 is compared ...

Absolute cross sections are reported for single, double, and triple charge exchange of Feq+ (q=5-13) ions with CO and CO2. The highly charged Fe ions are generated in an electron cyclotron resonance ion source. Absolute data are derived from knowledge of the target gas pressure, target path length, and incident and charge-exchanged ion ...

Absolute atomic oxygen ground state densities in a radio-frequency driven atmospheric pressure plasma jet, operated in a helium-oxygen mixture, are determined using diagnostic based modeling. One-dimensional numerical simulations of the electron dynamics are combined with time integrated optical emission spectroscopy. The population dynamics of the upper O ...

Absolute cross sections for photoionization and electron-impact ionization of Ar{sup 5+} have been measured using two different interacting-beams setups. The spectra consist of measurements of the yield of products due to single ionization as a function of electron or photon energy. In addition, absolute ...

A merged-beams electron-energy-loss technique is described, by which absolute cross sections can be measured for near-threshold electron-impact excitation of multipy charged ions. Results are reported here for absolute total electron-impact excitation cross sections for the O[sup 5+](2[ital ...

Single ionization of argon by 195-eV electron impact is studied in an experiment, where the absolute triple-differential cross sections are presented as three-dimensional electron emission images for a series of kinematic conditions. Thereby a comprehensive set of experimental data for ...

Absolute partial cross sections have been measured for the electron-impact ionization of the fullerene C{sub 60}. The single parent C{sub 60}+ ionization cross section is the most important ionization channel. Significant cross sections were also measured for some single fragment ionization channels and for the double and triple ionization of C{sub 60} and ...

The triple-deck equations for the flow over a hump, a corner and a wedged trailing edge are solved numerically using a novel method based on spectral collocation. It is found that for the flow over a corner, separation begins at a scaled angle g of 2.09, and for the wedged trailing edge for a wedge angle of 2.56. Here g is defined in terms of the small physical angle } by ...

Absolute partial cross sections from threshold to 1000 eV are reported for the production of Ar{sup {ital n}+} ({ital n}=1--4) by electron-impact ionization of argon. The total cross sections, obtained from an appropriately weighted sum of the partial cross sections, are also reported. These results are obtained with an apparatus incorporating a ...

The impact that transmission microscopy has made in the study of ceramics is illustrated by the following examples from current work: an absolute structure determination, the study of precipitation and order-disorder phase transformations in lithium ferrite, phase transitions and polytypism in silicon carbide and the investigation of grain boundaries in ...

Coincidence experiments for electron-impact ionization of helium in a symmetric coplanar energy-sharing geometry at incident energies from 45 to 500 eV and an angle of 45[degree] are described. Results are put on an absolute scale by normalization to elastic-scattering data and are compared to theoretical calculations in distorted-wave Born and ...

A crossed-beam setup was used to measure cross sections for electron-impact single and double ionization of W17 + ions. Absolute data and high-resolution scan spectra were obtained at collision energies ranging from threshold up to 1000eV. A comparison of the experimental results with theoretical calculations for direct ionization suggests substantial ...

Absolute cross sections for the single ionization of Tl$sup +$ ions by electron impact have been measured as a function of electron energy from below threshold to approximately 2000 eV. It was found that the cross section increased from a zero value at and below threshold to a maximum value of about 1.7 x ...

Absolute partial and total cross sections for electron-impact ionization of methanol, ethanol, and 1-propanol are reported for electron energies from threshold to 1000 eV. The product ions are mass analyzed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output demonstrates that all ...

Single ionization of helium by 70.6-eV electron impact is studied in a comprehensive experiment covering a major part of the entire collision kinematics and the full 4? solid angle for the emitted electron. The absolutely normalized triple-differential experimental cross sections are compared with results from the ...

Scaling laws and semiempirical methods can be powerful tools to predict electron-impact ionization cross-section data for modelling purposes and many other practical applications where a quick estimate of a large number of reasonably accurate cross-sections in analytical form is needed. Scaling laws can also be useful for the prediction of cross-section values for targets for ...

By correcting some primary parameters in the semi-classical Deutsch-M�rk (DM) formula, this paper calculates the absolute single electron-impact ionization cross sections of atoms N, Cu, As, Se, Sn, Sb, Te, I and Pb from threshold to 10000 eV. The calculated cross sections are compared with available experimental data and other theoretical results. An ...

The close-coupling approach to electron-helium single ionization is analyzed and several ways of defining the scattering amplitudes are determined, for both equal- and unequal-energy outgoing electrons. Nevertheless, the various definitions all lead to the same cross section. The convergent close-coupling (CCC) method with Laguerre (CCC-L) and box-based ...

The quantitative relation between fast electron impact and photoabsorption is discussed with reference to simulation of the technique of photoelectron spectroscopy. An apparatus is described that employs coincidence detection of scattered and ejected electrons resulting from ionization over a range of energy losses up to 70 ...

Some recent measurements of excitation of multiply charged ions by electrons studied in beam-beam experiments are highlighted. The emphasis is on absolute total cross sections measured with the merged electron-ion beams energy-loss (MEIBEL) technique, alt...

The excitation of transitions between the levels of the triplet system of the zinc atom is studied by the method of extended crossing beams. The absolute excitation cross sections are measured for electron energy of 30 eV and as functions of the incident electron energy in the range of 0-200 eV. It is found that, for all spectral ...

We report on progress made mapping Aristarchus Crater using high-resolution LROC NAC images. Observations include enigmatic impact melt features and stratified blocks of ejecta. An absolute model age using crater counts was also determined.

We report fully differential cross sections (FDCS) for the single ionization of helium by a 75 keV incident energy proton. Previous three-body distorted wave (3DW) calculations for this collision system are in poor agreement with the absolute magnitude of the experimental measurements. The 3DW approximation treats the four-body problem as an effective three-body problem in ...

Cross sections for electron loss of He+ and C3+ projectile ions on atomic and molecular hydrogen were measured in the 0.5-MeV<=E<=3.5-MeV energy range. The measurements of the ?H2/?H cross section ratios were made by using an absolutely calibrated hydrogen furnace. The influence of different models describing the form factor of molecular hydrogen is ...

Absolute cross sections for photoionization andelectron-impact Photionization of Ar5+ have been measuredusing twodifferent interacting-beams setups. The spectra consist of measurementsof the yield of products dueto single ionization as a function ofelectron or photon energy. In addition, absolute photoionization ...

the asteroid relative to the Earth, assuming a massless Earth. H Absolute Magnitude is an intrinsic measure of brightness. It is the apparent magnitude of the object when it is 1...

The paper presents absolute cross sections measured for 1s 2 2s 2S1/2-1s 2 2p 2P1/2,3/2 excitation of lithiumlike N(4+) by electron impact. Relative cross sections measured at several energies between 4 and 52 eV were normalized to a single absolute measurement taken at 15.5 eV for the process which has a threshold ...

Progress toward measurements of the absolute cross section for electron impact excitation (EIE) of C^2+ (2s2p ^3P^o - 2p^2 ^3P) for energies below threshold to 15 eV above is reported. These measurements will be used to determine the EIE rate coefficients required for astrophysical applications. Ions are produced in a 5 GHz ...

... Title : Lower Limits on the Absolute Dissociative Electron Attachment Cross Section from O2 Condensed on Rare-Gas Films. ...

... Accession Number : ADA216730. Title : Absolute Cross-Sections for Dissociative Electron Attachment in O2 Condensed on Kr Films. ...

... has been used to measure the absolute total electron-helium-atom scattering cross ... with increasing energy to a minimum of about 10% below the ...

Ionization curves near threshold were taken with a mass spectrometer employing a monoenergetic electron beam. These curves were fitted to previously published data from total ionization experiments in order to obtain absolute cross sections for the threshold energy region. Curves for helium, neon, argon, mercury, carbon monoxide, and nitro

A modified Glauber method proposed recently for electron-atom scattering is extended to the analysis of the 1-2 excitation of atomic hydrogen by electron impact. Exchange effects are not neglected, but included in the calculation through the exact eikonal exchange formulas. The results are compared with experimental data acquired by ...

Absolute optical cross sections for the excitation from the ground state of N2 by electron impact have been measured for 39 N2 first positive bands 12 N2(+) first negative bands, and 10 N2(+) Meinel bands. Relative excitation functions are presented for N...

Partial electron ionization cross section ratios and functions of Xe were determined in the low energy regime (< or =180 eV) using a refined mass spectrometric technique. The experimental results are compared with previous measurements and calculations.

from the old ORNL Penning ion gauge (PIG) ion source [22]. Further data are needed to determine whether-cyclotron-resonance (ECR) ion source at 10 kV and mass analyzed by a A4BDC bending magnet. The ion source is typically. Only the electron beam ion source (EBIS) measurements of Donets and Ovsyannikov [14] for energies

Doubly differential electron velocity spectra induced by 36Ar18 + (95 MeV/ u) from thin target foils (C, Ni, Ag, Au) were measured at GANIL (Caen, France) by means of the ARGOS multidetector and the time-of-flight technique. The main features observed in the forward spectra are convoy electrons, binary-encounter electrons, and (for ...

Ionization of JP-10 (C10H16, exo-tricycle [5.2.1.02,6] decane) by electron impact has been studied using Fourier transform mass spectrometry. Absolute total and partial ionization cross-sections have been measured as functions of the electron energy in the range of 10-200 eV. The major channel of parent ion ...

Results from measurements of absolute K-shell ionization cross sections and L{alpha} x-ray production cross sections of Ge by impact of electrons with kinetic energies ranging from the ionization threshold up to 40 keV are presented. The cross sections were obtained by measuring K{alpha} and L{alpha} x-ray intensities emitted from ...

A new apparatus has been constructed for the measurement of absolute partial electron-impact-ionization cross sections of neutral atoms, molecules, and free radicals. A fast neutral beam is prepared by charge-transfer neutralization of a mass-selected ion beam and is ionized as it crosses an electron beam. From careful analysis of the ...

Design and parameters of the photoionization quantometer are given. It is a combination of photoionization chamber with time-of-flight mass spectrometer. The quantometer is an absolute detector of radiation in the wavelength interval (100--0.1 nm) due to the fact that photoionization and electron-impact ionization cross sections of gases are used for ...

Absolute partial cross sections for electron-impact ionization of H{sub 2}, N{sub 2}, O{sub 2}, CO{sub 2} and SO{sub 2} from threshold to 1000 eV are reported. Data are presented for the production of the ionized parent molecules and various fragment ions. The product ions are mass analyzed with a time-of-flight mass spectrometer and detected with a ...

Doubly differential electron velocity spectra induced by 95-MeV/u 36Ar18+ from thin carbon foils were measured at GANIL (Caen, France) by means of the ARGOS multidetector and the time-of-flight technique. The spectra allow us to determine absolute singly differential cross sections as a function of the emission angle. Absolute doubly ...

Doubly differential electron velocity spectra induced by 95-MeV/u {sup 36}Ar{sup 18+} from thin carbon foils were measured at GANIL (Caen, France) by means of the ARGOS multidetector and the time-of-flight technique. The spectra allow us to determine absolute singly differential cross sections as a function of the emission angle. ...

A simple accurate method for normalizing the absolute magnitude of measured relative rare-gas excitation cross-section data to published measurements of the first Townsend coefficient is presented. Using a code which solved the Boltzmann equation we have determined that the predicted first Townsend coefficient is a very sensitive function of the electron ...

Multiple ionization cross sections (ICS) for atoms and molecules in gaseous phase have been studied in a linear time-of-flight (TOF) spectrometer, which was constructed in our laboratory. The feasibility of this instrument has been verified by determining multiple ionization reactions in the 90-3000 eV impact energy range. Emphasis is placed on the apparatus and techniques ...

The differential cross sections for excitation of the n = 2 state of atomic hydrogen by the impact of electrons with energies of 54, 100, 136, and 200 eV are calculated in the distorted-wave approximation with exchange included. Cross sections for excitation of the 2s/sub 1/2/, 2p/sub 1/2/, and 2p/sub 3/2/ states are calculated and summed to give the n = 2 ...

We have measured the cross section for excitation of the 468.6 nm line of 0953-4075/29/6/022/img2 by electron impact from threshold to 500 eV. The absolute values of the cross sections have been determined in terms of those for excitation of the neutral helium lines at 505 nm and 444 nm. We have designed and used a novel form of ...

Absolute cross sections for ionization of the Na-like ions Ti{sup 11+} and Cr{sup 13+} due to electron impact have been measured over the energy ranges 300--800 eV and 500--1500 eV, respectively. These measurements confirm predictions by Griffin, Pindzola, and Bottcher (Phys. Rev. A 36, 3642 (1987)) concerning the magnitude of indirect ...

Absolute photoemission cross section data have been measured for the dissociative excitation of H2S by electrons in the impact energy range from threshold to 300 eV. Emissions in the vacuum ultraviolet spectral region have been observed and quantified using emission from H2 as a secondary standard. Numerous dissociation pathways have ...

Absolute measurements have been made of single electron charge exchange cross ... Charge exchange is an important process in solar and stellar atmospheres, ...

It is proposed to use radiation from a femtosecond laser for absolute length measurements. The possibility of creation of a unified frequency and length standard is shown. (laser applications and other topics in quantum electronics)

... Report Date : 23 AUG 1972. Pagination or Media Count : 28. Abstract : Absolute electron yields from tantalum, molybdenum, copper and aluminum ...

and HCl by low-energy electron impact. An isotope scaling law * D.E. Atems and J.M. Wadehra Departmentof of Hz [ l-5 ] and of HCl [6- 9] have been measured by several different inves- tigators. The absolute to within 20%30%. Vibrational ex- citation of the heavier isotopes of H2 and HCl has been much less studied

A plasma diagnostic technique has been experimentally demonstrated where optical emission measurements of relative intensities of spectral lines in the violet range were combined with available electron-impact cross sections to yield absolute Ar metastabl...

Strong resonance features were observed in near-threshold excitation of (sup 1)S right arrow (sup 3)P intercombination transitions in Si(2+), Ar(6+), and Kr(6+). Such resonances are predicted to dominate over direct excitation by more than an order of mag...

Absolute apparent cross sections for electron-impact excitation out of the 2-triplet-S metastable level of He to the 3-triplet-S, 4-triplet-S, 3-triplet-P, 3-triplet-D, 5-triplet-D, and 6-triplet-D levels have been measured by a novel method. A beam of me...

This Perspective reviews the impact of exciton coupling on the spectroscopic properties of coordination compounds. Exciton coupling features arise in electronic absorption and circular dichroism spectra when chromophores are brought into close spatial proximity, for example by coordination to a metal centre. The analysis of these features can reveal much ...

Absolute apparent cross sections for electron-impact excitation out of the 2/sup 3/S metastable level of He to the 3/sup 3/S, 4/sup 3/S, 3/sup 3/P, 3/sup 3/D, 4/sup 3/D, 5/sup 3/D, and 6/sup 3/D levels have been measured by a novel method. A beam of metastable atoms from a hollow-cathode discharge is crossed by an electron beam of ...