An experiment to determine the absolute value of the photo-ionization cross section of atomic oxygen

The absolute cross section for photoionization of atomic oxygen from the 2p4 3P ground state of O(0)

An experiment to determine the absolute value of the photo-ionization cross section of atomic oxygen is described. The atoms are produced in an electrical discharge in oxygen gas with 1% hydrogen added. In order to prevent recombination a crossed beam tec...

The partial and total absolute cross sections for the photoionization of Xe+ and Xe2+ ions, respectively, have been measured in the 4d excitation region (50-130 eV). The experimental cross sections are compared with calculated values obtained by the random phase approximation method taking exchange and ...

Photoionization of multiply charged ions is studied using the merged-beams technique at the Advanced Light Source. Absolute photoionization cross sections have been measured for a variety of ions along both isoelectronic and isonuclear sequences.

The absolute cross sections for the production of N(+) and N2(+) were measured from the dissociative

Numerical simulations show that derived elemental abundances in astrophysical nebulae can be uncertain by factors of two or more due to atomic data uncertainties alone, and of these uncertainties, absolute photoionization cross sections are the most important. Absolute single photoionization ...

An apparatus is described in which merged beams of groundstate Ba(1+) ions and energy-resolved radiation from the Daresbury Synchrotron Radiation Source were used to obtain absolute cross sections for the photoionization of Ba(1+) in the wavelength range ...

This report discusses the absolute cross-section measurements of photoionization of helium at NSLS, and the future opportunities at the Advanced Photon Source and other third generation synchrotron light sources.

... Abstract : We have developed an octopole-quadrupole photoionization apparatus at the Advanced Light Source for absolute integral cross-section ...

... mass spectrometer into the high-resolution photoion ... induced dissociation (CID) and charge transfer (CT ... to reject false coincidence ions, we have ...

Photoionization spectra have been recorded in the 4s, 4p, and 3d resonance regions for the Kr I isoelectronic sequence using both the dual laser produced plasma (DLP) technique (at DCU) to produce photoabsorption spectra, and the merged ion beam and synchrotron radiation technique (at ASTRID) to measure absolute photoionization ...

The absolute photoionization cross-sections of aromatics and aromatic derivatives including toluene, ethylbenzene, n-propylbenzene, o-xylene, m-xylene, p-xylene, 1,3,5-trimethylbenzene, styrene, phenylacetylene, indene, indane, 1-methylnaphthalene, benzyl alcohol and benzaldehyde were measured at the photon energy range from ionization ...

The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A...

Partial cross sections for molecular photoionization (CO(+)), dissociative photoionization (C(+) and

Photoionization of multiply charged ions is studied using the merged-beams technique at the Advanced Light Source. An ion beam is created using a compact 10-GHz all-permanent-magnet ECR ion source and is accelerated with a small accelerator. The ion beam is merged with a photon beam from an undulator to allow interaction over an extended path. Absolute ...

Research is reported in measurement of absolute cross sections for the photoionization of heavy rare gas metastable atoms by use of a crossed beams technique. This effort included the development of a high power, pulsed, tunable ultraviolet and vacuum ult...

The photoionization cross sections of barium and strontium were determined experimentally. Measurements were made using an atomic beam crossed by an ultraviolet light beam and by absolute measurement of the three independent parameters: atomic number dens...

The use of photoionization mass spectrometry for the development of quantitative kinetic models for the complex combustion chemistry of both conventional hydrocarbon fuels and oxygenated biofuels requires near-threshold measurements of absolute photoionization cross-sections for numerous reaction intermediates. ...

The absolute photoionization cross sections of I+ and I2+ ions have been measured from 45 to 140 eV, covering the region of 4d ionization where a large maximum, also known as a ``giant resonance,'' occurs in the cross section. For both ions, the maximum cross section appears near 90 eV and is ...

... Accession Number : AD0623909. Title : THE PHOTOIONIZATION CROSS SECTION OF SOME ATOMIC SYSTEMS. Descriptive ...

... Accession Number : AD0703628. Title : CROSS SECTION FOR PHOTOIONIZATION OF EXCITED CESIUM ATOMS. Descriptive ...

Updated recommended data for absolute photoionization cross sections of Kr and Xe with uncertainties of {+-} 3 % are presented. The data are the result of a comprehensive analysis of reliable experimental measurements in absolute terms taking preceding recommendations into account. Significant corrections of the ...

In this work, we report an experimental investigation into the interaction of vacuum-ultraviolet radiation with tetrahydrofuran molecules in the gas phase. More specifically, absolute photoabsorption cross sections and photoionization quantum yields are measured and reported in the (11.11-21.45) eV energy range. In addition, ...

Cross sections for photoionization of doubly-chargedscandium ions has been measured using a merged-beams technique. Resultsare compared with the time-reversed process ofphotorecombination.

The first absolute photoion-pair cross sections have been derived from measurements of the absolute photoabsorption cross section and the photoion-pair quantum efficiency. The results for CH3Cl, CH3Br and CF2Cl2 show that direct transitions into ion-pair states play a ...

The absolute photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH{sub 3} photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed ...

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 - ...

The absolute photoionization cross section of C(2)H(5) has been measured at 10.54 eV using vacuum ultraviolet (VUV) laser photoionization. The C(2)H(5) radical was produced in situ using the rapid C(2)H(6) + F ? C(2)H(5) + HF reaction. Its absolute photoionization ...

Measurement of absolute cross sections for photoionization of ions has become feasible by merging a well-collimated ion beam with a monochromatic beam of synchrotron radiation. An electron cyclotron resonance (ECR) ion source permits such measurements to be extended to multiply charged ions, and makes possible systematic studies along ...

Coupling an ion trap with synchrotron radiation is shown here to be a powerful approach to measure photoionization cross sections on ionic species relaxed in their ground state. The photoionization efficiency curve of Xe+ ions stored in a Fourier transform ion cyclotron resonance ion trap was recorded at ELETTRA in the 20-23 eV photon ...

Coupling an ion trap with synchrotron radiation is shown here to be a powerful approach to measure photoionization cross sections on ionic species relaxed in their ground state. The photoionization efficiency curve of Xe{sup +} ions stored in a Fourier transform ion cyclotron resonance ion trap was recorded at ELETTRA in the 20-23 eV ...

Using a photoionization depletion method to measure the flux of a metastable atom beam in situ we have determined absolute cross sections for photoionization of the excited rate gas atoms Ar*(4p {sup 3}D3, Kr*(5p {sup 3}D3) and Xe*(6s {sup 3}P0) in a cross beam arrangement. The overlap of the ...

Jan 1, 1979 ... The molecular photoionization, dissociative photoionization and double photoionization cross sections for CO2 were measured from their ...

The determination of elemental abundances in astrophysical nebulae is highly dependent on the accuracy of atomic data. Absolute single photoionization cross sections for Se^+, Se^2+, Se^3+, Se^5+, Xe^+ and Xe^2+ have been measured at the ALS at Lawrence Berkeley National Laboratory using the merged-beams technique. All ions except ...

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 ...

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 ...

Here we report a set of converged cross-section results for double photoionization of helium atoms obtained in the hyperspherical partial wave theory for equal energy sharing kinematics at 6 eV energy above threshold. The calculated cross section results are generally in excellent agreement with the absolute ...

Photodissociation of acetaldehyde (CH3CHO) at 266 nm produced CH3 and HCO radicals, and single-photon vacuum ultraviolet ionization was used to record velocity map ion images of both CH3+ and HCO+. Comparison of the translational energy distributions from both species indicates that secondary fragmentation of HCO is negligible for 266 nm photodissociation. Thus, the relative ...

The absolute photoionization cross section for the astrophysically important C+ ion has been measured for the first time thus allowing a test of the predicted cross section from the Opacity Project. The measurements are performed with a new ion-photon merged beam setup at the ASTRID storage ring utilizing an ...

... Title : THE PHOTOIONIZATION CROSS SECTION OF NEON FROM 80A TO 600A,. ... Descriptors : , NEON, PHOTOELECTRICITY. ...

Absorption cross sections of helium, neon, argon, krypton, and xenon from photoionization thresholds

Be photoionization cross section calculated noting autoionization dominance near threshold, 1P phase

... Accession Number : AD0617461. Title : PHOTOIONIZATION CROSS SECTION OF NEON IN THE 80 TO 600 A REGION,. ...

... Accession Number : AD0725058. Title : Measurement of the Photoionization Cross Section in the Resonance Continuum of Carbon-I. ...

The cross section for two-electron photoionization of the hydrogen molecule by high-energy photons is predicted in the nonrelativistic dipole approximation to be 2.25% of the cross section for single photoionization.

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 ...

The properties of Argon ions are of importance in atmospheric and astrophysical plasmas where abundances are required in the modeling of B-type stars in the Orion nebula, and the interstellar medium. Absolute cross-section measurements made at the Advanced Light Source in Berkeley California, for M-shell photoionization of Ar^+ are ...

Absolute photoionization and dissociative photoionization cross-sections of eleven n-alkanes (n-pentane, n-hexane, n-heptane, n-nonane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane and n-hexadecane), three cyclo-alkanes (cyclopentane, methylcyclohexane and trans-decahydronaphthalene) ...

A new method to compute fully differential double photoionization cross sections of atoms has been devised and fully developed for two-electron systems. The method exploits the Green function for two noninteracting electrons in the field of a nuclear charge to infer the effects of the residual potential projected on a set of L(2)-basis functions. Test ...

We present new measurements of the photoionization cross section from the 5s5p 1P1 state employing two-step excitation and from the 5s6s 1S0 state using two-photon excitation and then a second laser for subsequent ionization in each case. The two dye lasers, pumped by a common Nd:YAG laser, have been used in conjunction with a thermionic diode ion detector ...

The absolute photoionization cross section of the methyl radical was determined relative to that of NO at photon energies of 10.54 eV using the CH(3) + NO(2) --> CH(3)O + NO reaction. Kinetics of this reaction was studied in a fast flow reactor coupled with VUV laser photoionization. Simulation of the kinetics ...

There has been only a limited amount of experimental investigation of the photoabsorption and photoionization processes of the OH radical. In this paper, we present ab initio calculations of photoionization cross sections and photoelectron angular distrib...

The photoionization entity p may be regarded as an addendum of the energy .... In this example, we want to plot the photoionization cross sections of the ...

Absolute cross-section measurements for K-shell photoionization of Be-like C2+ ions have been performed in the photon energy range 292 325 eV. These measurements have been made using the photon ion merged-beam endstation at the Advanced Light Source, Lawrence Berkeley National Laboratory. Absolute measurements ...

xsect: set the photoionization cross-sections. Change the photoelectric absorption cross-sections in use. Syntax: xsect [bcmc|obcm|vern] ...

A compilation is provided of absolute total photoabsorption and partial-channel photoionization cross sections for the valence shells of selected molecules, including diatomics (H2, N2, O2, CO, NO) and triatomics (CO2, N2O), simple hydrides (H2O, NH3, CH4), hydrogen halides (HF, HCl, HBr, HI), sulfur compounds (H2S, CS2, OCS, SO2, ...

This work describes a fast and reliable method for determination of photoionization cross-sections (PICS) by means of gas chromatography (GC) coupled to single-photon ionization mass spectrometry (SPI-MS). Photoionization efficiency (PIE) data for 69 substances was obtained at a photon energy of 9.8 � 0.4 eV using an innovative ...

Absolute photoionization cross sections for Kr{sup 5+} were measured in the photon energy range 74-175 eV using synchrotron radiation. For comparison, a detailed energy scan of the electron-impact ionization cross section was made in the same energy range and normalized to previously published ...

We report the first use of synchrotron radiation, continuously tunable from 8 to 15 eV, for flame-sampling photoionization mass spectrometry (PIMS). Synchrotron radiation offers important advantages over the use of pulsed vacuum ultraviolet lasers for PIMS; these include superior signal-to-noise, soft ionization, and access to photon energies outside the limited tuning ranges ...

Absolute cross-section measurements for valence-shell photoionization of Ar+ ions are reported for photon energies ranging from 27.4 to 60.0 eV. The data, taken by merging beams of ions and synchrotron radiation at a photon energy resolution of 10 meV, indicate that the primary ion beam was a statistically weighted mixture of the ...

Photoionization of triply charged titanium ions was investigated using the merged photon-ion beam technique at a synchrotron light source. The experimental photon energy range 42.6-49.4 eV encompasses the threshold for the photoionization of Ti3+(3p6 3d2 D3/2) ground-state ions at 43.267 eV. Prominent resonance features due to 3p rarr 3d and 3p rarr 4s ...

Saturation technique has been employed to measure the oscillator strength distribution in spectra of helium lithium using an electrical discharge cell a thermionic diode ion detector respectively. The photoabsorption cross sections in the discrete or bound region (commonly known as f-values) have been determined form the Rydberg series accessed from a particular excited state ...

A crossed photon-atom beam apparatus has been constructed for absolute measurement of total photoionization cross sections of isolated and neutral metallic atoms. The main purpose is to establish the technique which can be used as widely as possible for the metallic elements. Using this apparatus, measurements on ...

We report on strong interference effects for the dominant, highly correlated, broad, and asymmetric 3p53d2(2F5/2,7/2o) giant resonances in the photorecombination of Sc3+. Using a nonorthogonal perturbative multiconfiguration Breit-Pauli approach, we present theoretical photorecombination cross sections that are in line with the Test Storage Ring measurements of Schippers In ...

The molecular photoionization, dissociative photoionization and double photoionization cross sections for CO2 were measured from their onsets down to 90 A by using various combinations of mass spectrometers (a coincidence time-of-flight mass spectrometer ...

Acetaldehyde was photodissociated with near UV laser light, and the methyl (CH_3) and formyl (HCO) radical fragments were photoionized with vacuum ultraviolet (VUV) light. The fragments were detected by using both time of flight mass spectrometry and velocity ion map imaging. With the former technique, simultaneous detection of both fragments provided the intensity of HCO+ ...

Cross sections for single photoionization of Fe3+, Fe5+, and Fe7+ ions were measured at spectral resolutions of 0.04, 0.15, and 0.13 eV, respectively, by merging mass- and charge-selected ion beams with a beam of monochromatized synchrotron undulator radiation. The measurements span photon energy ranges beginning at the ionization thresholds and extending ...

We present studies of resonance-enhanced photoionization for isotope-selective loading of Ca+ into a Paul trap. The 4s2 1S0?4s4p 1P1 transition of neutral calcium is driven by a 423 nm laser and the atoms are photoionized by a second laser at 389 nm. Isotope selectivity is achieved by using crossed atomic and laser beams to reduce the ...

Absolute single photoionization cross-section measurements for Se+ ions were performed at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory using the photo-ion merged-beams technique. Measurements were made at a photon energy resolution of 5.5 meV from 17.75 to 21.85 eV spanning the 4s24p3 ...

... Title : Photoabsorption and Photoionization Cross Sections of O, O2, and N2 for Photoelectron Production Calculations: A Compilation of Recent ...

... Accession Number : AD0756217. Title : Cross Section for Photoionization of Excited Cesium Atoms. Descriptive Note : Technical rept. no. ...

... Accession Number : AD0741222. Title : Cross Section for Photoionization of Excited Cesium Atoms. Descriptive Note : Technical rept. no. ...

photoionization cross section from level i of the recombined ion to the ground level of ... The photoionization cross-sections from the ground level of the ...

This work measured the absolute photoabsorption cross section of propyne (methylacetylene, CH3CCH) in the 6-30 eV energy range. The valence-shell oscillator strength of 16.97 and the static dipole polarizability of 35.82 atomic units (5.31 �3) were also derived from the photoabsorption spectrum by the sum-rule method. In the ...

Using the configuration interaction Pauli-Fock including core polarization (CIPFCP) approach we have calculated absolute total and partial cross sections for photoionization of excited mp 5( m + 1) p J = 0-3 levels in Ar, Kr and Xe ( m = 3-5) near threshold. Particular emphasis is paid to the lineshapes of the odd mp {1/2/5} n( s/ d)' ...

A pyrolysis source coupled to a supersonic expansion has been used to produce the CH3 radical from two precursors, iodomethane CH3I and nitromethane CH3NO2. The relative ionization yield of CH3 has been recorded at the SOLEIL Synchrotron Radiation source in the range 9.0-11.6 eV, and its ionization threshold has been modeled by taking into account the vibrational and rotational temperature of the ...

Using synchrotron radiation, absolute single photoionization cross sections were measured in the photon energy ranges 39.05--143.2 eV for Kr 3+ , 59.1-- 155.9 eV for Kr 4+ and 74--175 eV for Kr 5+ . Absolute double photoionization cross sections for Kr 3+ were also measured ...

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 ...

In order to more fully explore the role of electron correlations in the photoionization process the hyperspherical coordinate method of Macek was employed in calculating photoionization cross sections of He. Results are presented and discussed.

The complete valence shell photoelectron spectrum of silicon tetrafluoride has been studied both experimentally and theoretically. Photoelectron angular distributions and branching ratios have been measured in the photon energy range 17-120 eV, using synchrotron radiation, and compared with previous theoretical predictions. The spectra demonstrate that shape resonance phenomena affect the ...

We investigate the loading rate of Yb+ ions loaded through photoionization in a radiofrequency trap. The absolute or relative number of the loaded trapped ions is measured by use of an electric resonance of the secular motion. This method is applicable even in the presence of anharmonicity. In two-color photoionization, where the ...

The photoionization of propiophenone via two different routes was investigated by single-pulse and two-pulse laser-flash photolysis with observation of the hydrated electron and the respective photoionizable intermediate, the triplet or the radical anion. From the dependences of the absolute concentrations on the excitation intensity, kinetic constants and ...

... Title : ABSOLUTE RAYLEIGH SCATTERING CROSS SECTIONS OF GASES AND FREONS OF STRATOSPHERIC INTEREST IN THE VISIBLE ...

Absolute photoionization measurements were performed for a mixture of 2P3/2o ground-state and 2P1/2o metastable-state Ca3+ ions over the photon energy range 65.7-104.6 eV by merging an ion beam with a beam of monochromatized synchrotron radiation. The ionization threshold energy of the 2P3/2o ground state was measured to be 67.063 � 0.015 eV, which is ...

Recombination. Radiative and dielectronic recombination rates to all spectroscopic levels are calculated from the photoionization cross sections using the ...

Absolute cross sections for the K-shell photoionization of C-like nitrogen ions were measured by employing the ion�photon merged-beam technique at the SOLEIL synchrotron radiation facility in Saint�Aubin, France. High-resolution spectroscopy with E/?E ? 7000 was achieved with the photon energy from 388 to 430 eV scanned with a band ...

The hyperspherical R-matrix method with semiclassical outgoing waves is used to study the direct double photoionization (DPI) of the valence shell of the lightest alkaline earth-metal Be. The absolute fully integrated, singly, doubly, and triply differential cross sections obtained are compared with the single set of measurements ...

Ion pair formation, generically described as AB-->A++B-, from vacuum-UV photoexcitation of trifluoromethyl sulfur pentafluoride, SF5CF3, has been studied by anion mass spectrometry using synchrotron radiation in the photon energy range of 10-35 eV. The anions F-, F2-, and SFx- (x=1-5) are observed. With the exception of SF5-, the anions observed show a linear dependence of signal with pressure, ...

Iron K shell photoionization cross sections. ADAS Dielectronic Recombination ( Badnell). Iron M shell UTA data (Gu). Verner and Yakovlev Photoionization.

Ralf Wehlitz. Synchrotron Radiation Center, UW-Madison, Stoughton, WI 53589. ABSTRACT. The threshold region of the double-photoionization cross section is ...

and G. Ulm, Measurements of Electron-Impact Ionization Cross Sections of Argon, Krypton, and Xenon by Comparison with Photoionization, ...

... for monochromatic incident radiation in the wavelength range 584 - 900A. For each gas, cross sections were determined for transitions to particular ...

The R-matrix theory of photoionization described by Burke and Taylor (1975) is used to obtain cross sections for the photoionization of ground-state carbon and oxygen atoms. The calculations are the first to couple systematically all channels correspondin...

A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters ...

Absolute measurements of cross sections for photoionization of a statistical admixture of Ne{sup +} in the {sup 2}P{sub 3/2}{sup o} ground state and the {sup 2}P{sub 1/2}{sup o} metastable state are reported in the energy range 40-71 eV at photon energy resolutions ranging from 22 meV to 2 meV. The experiments were performed using ...

We use Hartree-Slater self-consistent-field wave functions to compute photoionization and photorecombination cross sections and rates for partially ionized iron atoms, both in their isolated state and in a plasma environnment. The calculated cross section...

A photoelectron energy spectrometer was used to determine partial photoionization cross sections of molecular oxygen, nitrogen and water vapour for monochromatic incident radiation in the wavelength range 584 - 900A. For each gas, cross sections were dete...

This dissertation presents an experimental photoionization study of the first three ionic members of the nitrogen isoelectronic sequence performed by merging an ion beam with a photon beam produced by an electron synchrotron. The ion-photon-beam apparatus and the electron-cyclotron-resonance ion source designed and constructed for this research are described, along with the ...

Absolute photoionization cross sections for Kr{sup 3+} were measured in the energy range 39.05-143.2 eV for single ionization and 120.6-137.7 eV for double ionization. For comparison, an electron-impact single-ionization measurement was made in the energy range 43.1-179.1 eV and normalized to previously published ...

There were two main goals in the experimental study of photoionization. One was to provide accurate data on the results of photon-atom collisions, studying the absolute probability for ejecting electrons from specific orbitals and determining their angula...

Absolute photoionization and absorption coefficients of N2O gas have been measured in the 600 to 1000A region with a 1-m Seya-Namioka type scanning vacuum ultraviolet monochromator. The Hopfield helium continuum was used as a background source with photoe...

The hydride anion H- would not be bound in the absence ofelectron correlation. Electron correlation drives the doublephotoionization process and, thus should impact double photoionizationresults most strongly for H-. We present fully differential crosssections for the three-body breakup of H- by single photon absorption.The absolute triple-differential and single-differential ...

Simple analytic formulas are proposed to fit the theoretical Hartree-Dirac-Slater K-shell photoionization cross sections of atoms and ions with atomic number of 26 or higher. It is shown that the criterion of Kamrukov et al. (1983) permits the description of many cross sections for a variety of atoms and ions. Fitting parameters are ...

A calculation of the photoionization cross sections is presented for alkali-metal atoms such as Li and Na in plasma environments. The computational scheme is based on the complex coordinate rotation method. A model potential formalism has been used to simplify the computational complexity of the problems of making quantitative predictions of properties and ...

A calculation of the photoionization cross sections is presented for alkali-metal atoms such as Li and Na in plasma environments. The computational scheme is based on the complex coordinate rotation method. A model potential formalism has been used to simplify the computational complexity of the problems of making quantitative predictions of properties and ...

... Title : Absolute Absorption Cross Section Measurements of Ozone and the Temperature Dependence at Four Reference Wavelengths Leading to ...

Variations in photoionization cross sections, or transition moments, over the vibrational envelope of photoelectron transitions are investigated. Differential photoionization cross sections within the orthogonalized plane-wave approximation and Frank-Cond...

The photoionization cross section is partitioned into its components by analyzing the emitted photoelectrons according to energy and intensity. the principle of the method is outlined and experimental results on neon, krypton, manganese and beryllium are discussed. 9 refs., 7 figs.

Recent experiment on K/sup +/ is compared with measurements on neutral K to test the suggestion that inner-shell photoionization cross sections are largely unaffected by the removal of outer-shell electrons.

A simple model is presented for calculating the photoionization cross-section spectra of a two-electron center in silicon. A hydrogenlike function is used for the ground state of the singly ionized one-electron center, and a heliumlike wave function for t...

Recent experiment on K+ is compared with measurements on neutral K to test the suggestion that inner-shell photoionization cross sections are largely unaffected by the removal of outer-shell electrons. Potassium, Reprints. (mjm)

The use of the Random Phase Approximation with Exchange (RPAE) for calculating partial and total photoionization cross sections and photoelectron angular distributions for open shell atoms is examined for atomic chlorine. Whereas the RPAE corrections in a...

A model for calculating relative molecular orbital photoionization cross sections in the soft X-ray region is discussed. The model involves relative atomic subshell photoionization cross sections for the valence electrons and gross atomic charges from mol...

Experimental data on photoionization cross sections for hydrogen atom in the presence of a static electric field (F) are discussed. Atom highly excited Stark states manifest themselves in resonace cross section strucure. It has been pointed out that ''sma...

The objective of the present program is to determine the cross section for photoionization of excited cesium atoms. The highlight of the experiment is to use a thermally tunable gallium-arsenide laser to generate a high concentration of atoms in the first...

The photoionization cross section is partitioned into its components by analyzing the emitted photoelectrons according to energy and intensity. the principle of the method is outlined and experimental results on neon, krypton, manganese and beryllium are ...

A method is outlined for the calculation of photoionization cross sections representing the initial state by a minimal basis set STO NG wavefunction and the final state by the plane wave approximation. Numberical results for several small molecules compar...

... PART 2: PLASMA PHYSICS. ... Photoionization in MPD generators, Cross section measurements and transport properties in seeded inert gas MPD ...

... This seems to be the first determination of cross sections for solvated electrons and the Na(-) species in a liquid solution of high ionic conductivity. ...

Measurement of photoionization cross section between 400 to 600 angstroms for new autoionized energy

... Descriptors : *Plasma diagnostics, *Atomic beams, Nuclear fusion, Atomic energy levels, Excitation, Gas ionization, Photoionization, Cesium, Cross ...

The nonthermal and plasma screening effects on the x-ray photoionization process are investigated in astrophysical Lorentzian plasmas. The screened atomic wave function and energy eigenvalue of the target ion in Lorentzian plasmas are obtained by the Rayleigh-Ritz variational method. The x-ray retardation and screened Coulomb corrections are considered to obtain a ...

Although a great deal of effort has been devoted to investigating dipole photoionization of plasma-embedded atoms, far less is known about the corresponding quadrupole transitions. In the present work, quadrupole photoionization processes for the ground and excited states of hydrogen atoms in Debye plasma are explored using the method of complex coordinate ...

A literature review on the present state of knowledge in photoionization is presented. Various experimental techniques that have been developed to study photoionization, such as fluorescence and photoelectron spectroscopy, mass spectroscopy, are examined. Various atoms and molecules were chosen to illustrate these techniques, specifically helium and xenon ...

We present calculations for the double photoionization (with excitation) and the triple photoionization of Li and Be. We extend and more fully discuss the previous calculations made for Li by Colgan et al. [Phys. Rev. Lett. 93, 053201 (2004)] and present calculations for Be. The Be triple photoionization cross ...

The conversion rules under which an algebraic expression can be obtained from a corresponding photoionization Goldstone diagram have been given systematically in the present work. The electronic correlations in the photoionization processes then could be studied diagrammatically. The application to atomic scandium shows that the present theoretical scheme ...

Absolute single photoionization cross section measurements are presented for Se+, Se2+, Se3+ and Se 5+. These measurements were performed at undulator beamline 10.0.1 of the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory using the merged-beams technique. All ions except Se5+ were measured from the energy region of ...

We present studies of resonance-enhanced photoionization for isotope-selective loading of Ca{sup +} into a Paul trap. The 4s{sup 2} {sup 1}S{sub 0}{r_reversible}4s4p {sup 1}P{sub 1} transition of neutral calcium is driven by a 423 nm laser and the atoms are photoionized by a second laser at 389 nm. Isotope selectivity is achieved by using ...

Collision processes with highly charged xenon ions are of interest for UV-radiation generation in plasma discharges, for fusion research and for space craft propulsion. Here we report results for the photoionization of Xe^7+ ions ootnotetextS. Schippers et al., J. Phys.: Conf. Ser. (in print) which were measured at the photon-ion end station of ALS beamline 10.0.1. As compared ...

The asymptotic ratios of double-to-single photoionization cross sections of plasma-embedded helium atoms at very high but nonrelativistic photon energies are calculated for different shielding parameters that are based on the Debye model for weakly coupled plasmas. The ratio of double-to-single photoionization for free atom is ...

Within the framework of a model of a hollow atom as a hydrogenlike multicharged ion located at the center of a spherical shell formed by highly excited electrons, the photoionization cross sections of the inner 1s level of the ion have been calculated. The results show that the existence of the outer electronic shell of the hollow atom results in ...

Partial cross sections for molecular photoionization (CO(+)), dissociative photoionization (C(+) and O(+)), and dissociative double photoionization (C(2+)) in CO have been measured from their thresholds to 90 A using techniques of mass spectrometry. The results are compared with data reported previously. Several ...

... reaches about one-third of the total cross section. ... eV both the Xe(+) and Xe(++) cross sections increase; here ... which involves first the removal of a ...

TABLE OF CONTENTS 1. Introduction 888 2. Initial experiments 889 3. Methods of quantitative study of photoionization 889 4. Variation of the photoionization efficiency near the appearance thresholds of ions 891 5. The semi-empirical method of calculating the ionization potentials of organic compounds 893 6. Photoionization ...

This paper reports a study of valence photoionization of the LiCl monomer and dimer. The behavior of the photoionization partial cross section for molecular valence orbitals was measured as a function of photon energy between 15 and 35 eV. A square-integrable-function method was used to model the ionization partial ...

Using the perturbation approach, we have calculated the donor impurity related photoionization cross-section in a quantum dot under different temperature and hydrostatic pressure conditions. Our calculation have revealed the dependence of the photoionization cross-section on the confinement strength, temperature ...

Photo-ionization yields in the band series in N2 from 734 to 796 A are computed using the narrow bandwidth photo-absorption cross sections of Carter and the relative photo-ionization cross sections of Berkowitz and Chupka. The relative data are normalized...

This paper presents the methodology to generate beams of ions in single quantum states for bimolecular ion-molecule reaction dynamics studies using pulsed field ionization (PFI) of atoms or molecules in high-n Rydberg states produced by vacuum ultraviolet (VUV) synchrotron or laser photoexcitation. Employing the pseudocontinuum high-resolution VUV synchrotron radiation at the Advanced Light Source ...

We present experimental results obtained from photoionization and photodissociation processes of abundant interstellar methanol (CH3OH) as an alternative route for the production of H3+ in dense clouds. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS) employing soft X-ray and time-of-flight mass spectrometry. Mass spectra were obtained using the ...

By employing an electric field pulsing scheme for vacuum ultraviolet laser pulsed field ionization-photoion (PFI-PI) measurements, we have been able to prepare a rovibrationally selected PFI-PI beam of N(2)(+)(v(+) = 1, N(+)) with not only high intensity and high quantum state purity, but also high kinetic energy resolution, allowing absolute total ...

By employing an electric field pulsing scheme for vacuum ultraviolet laser pulsed field ionization-photoion (PFI-PI) measurements, we have been able to prepare a rovibrationally selected PFI-PI beam of N2+(v+ = 1, N+) with not only high intensity and high quantum state purity, but also high kinetic energy resolution, allowing absolute total ...

Absolute W values for krypton have been measured for incident X rays with energies in the range of 85 to 1000 eV, using monochromatic synchrotron radiation and a multiple-electrode ion chamber technique that yields the absolute intensity of the X-ray beam and the photoabsorption cross section. To improve the purity of the incident X ...

Absolute cross-section measurements for resonant doublephotoexcitation of Li+ ions followed by autoionization have beenperformed at high resolution in the photon energy range from 148 eV, justbelow the (2s2p, 2(0,1)n+) resonance, to 198 eV (the region of the doubleionization threshold). The measurements have been made using thephoton-ion merged-beam ...

Inner-shell excitation and fragmentation of chlorine dioxide (OClO) in the Cl 2p- and O 1s-excitation regime is reported. The electronic structure of the element-selectively excited radical is studied by X-ray absorption and total cation yields. A comparison of both approaches allows us to estimate the absolute photoionization ...

Neutral C60 is well known to exhibit a giant resonance in its photon absorption spectrum near 20 eV. This is associated with a surface plasmon, where delocalized electrons oscillate as a whole relative to the ionic cage. Absolute photoionization cross-section measurements for C+60, C2+60, and C3+60 ions in the 17-75 eV energy range ...

Absolute K-shell photoionization cross sections for atomic nitrogen have been obtained from both experiment and state-of-the-art theoretical techniques. Because of the difficulty of creating a target of neutral atomic nitrogen, no high-resolution K-edge spectroscopy measurements have been reported for this important atom. Interplay ...

Absolute K-shell photoionization cross sections for atomic nitrogen have been obtained from both experiment and state-of-the-art theoretical techniques. Because of the difficulty of creating a target of neutral atomic nitrogen, no high-resolution K-edge spectroscopy measurements have been reported for this important atom. Interplay ...

First photodetachment spectroscopy on negative ions of C60 has been conducted, using the merged ion-photon beam apparatus at the ALS with photon energies from 20eV up to 320eV. Multiple electron ejection was substantial at all photon energies, allowing product charge states up to 3+ to be measured. Fragmentation into cations of C58, and C56, was also studied. The relative strengths of the 7 ...

Experimental work is planned for (1) measurement of the photoionization cross section of krypton in the region 80 to 150 Angstroms and (2) examination, in both absorption and emission, of the elements adjoining xenon because of the large 4d shell photoion...

The radiative-recombination rate coefficients for electrons impinging on Li[sup +], along with the associated excited-state photoionization cross sections for Li, are calculated in the low-energy region. In addition to the totals, the contribution of the recombination of individual excited states to the total is discussed.

The photoionization cross section of argon and krypton was measured in the 100 to 300 angstrom range. A shallow minimum was found at 270 angstroms, in agreement with a calculation by Cooper. For krypton, the M4,5 edge was found at about 133 angstroms in a...

Determinations of the photoionization cross sections of ground state magnesium atoms and excited state sodium atoms have been made over a wide wavelength range. The ground state measurement in magnesium was performed using synchrotron radiation from the u...

Absolute photoionization cross-section measurements for a mixture of ground and metastable states of Xe{sup 4+}, Xe{sup 5+}, and Xe{sup 6+} are reported in the photon energy range of 4d{yields}nf transitions, which occur within or adjacent to the 13.5 nm window for extreme ultraviolet lithography light source development. The reported ...

Published experimental integrated electric dipole photoionization oscillator strengths (fij) have been applied to the determination of absolute electron impact excitation cross sections of the N2 X 1?g+(0) state into the N2+ X 2?g+(v), A 2?u(v), and B 2?u+(v) states. The required relative electron impact cross ...

The detection of neutron(n)-capture elements (atomic number Z>30) in the spectra of nearly 100 planetary nebulae (PNe; Sterling & Dinerstein 2008, ApJS, 174, 157) demonstrates that nebular spectroscopy is a potentially powerful new tool to investigate n-capture nucleosynthesis and the chemical evolution of trans-iron elements in the Universe. Nebular spectroscopy provides access to several ...

An experimental technique for the measurement of the total cross section for electron scattering from atoms and molecules at high resolution is described. The total cross sections for electron scattering from Kr in the energy range from 14 meV to 20 eV obtained with the technique are also reported. The present technique employs a combination of the ...

The procedures and status of the absolute measurement of the neutron capture cross sections for exp 115 In and exp 232 Th are described. Work on the exp 239 Pu fission fragment anisotropy and absolute measurement of the fast neutron fission cross section ...

We present a time-dependent localized Hartree-Fock density-functional linear response approach for the treatment of photoionization of atomic systems. This approach employs a spin-dependent localized Hartree-Fock exchange potential to calculate electron orbitals and kernel functions, and thus can be used to study the photoionization from atomic excited ...

The photoexcited triplet state and the photoionization of chlorophyll a (Chl a) in frozen egg phosphatidylcholine (EPC) vesicles are observed by electron spin resonance (ESR) spectroscopy at 77 K. The triplet state is detected with a light intensity modulation technique. By adding NaI to the vesicle solution, a significant increase in the intersystem ...

Selective photoionization of U-235 was demonstrated in a beam of uranium vapor using a tunable CW dye laser and a Hg arc lamp. The ions thus generated were then separated from the atomic beam by means of electrostatic deflection. The apparatus in this experiment was set up primarily to evaluate various parameters associated with two step processes in uranium vapor; such as ...

Two approaches were taken to calculate the photoionization rates for the ionosphere. First, a detailed line-by-line deposition for the range 1 to 1215A was carried out by using experimental or theoretical absorption and ionization cross sections for the atmospheric species. The second approach was to contnact these lines into bands having ...

An experimental apparatus consisting of a novel multiple expansion cluster source coupled with a molecular beam system and photoionization mass spectrometer has been designed and constructed. This apparatus has been thoroughly tested and preliminary measurements of the growth kinetics of water clusters and the photoionization cross ...

It is demonstrated that by taking into account many-electron correlations within the framework of the generalized random-phase approximation with exchange, it becomes possible to describe within the experimental error the recently obtained data [Kjeldson et al. Phys. Rev. A 62, 020702(R) (2000)] on the photoionization of iodine ions I+ and I2+ near and above the 4d10-subshell ...

The lifetime of triplet benzene produced by laser excitation of the 6/sup 1/ level of the S/sub 1/ state in a supersonic beam has been measured by photoionization with an ArF excimer laser. This collision-free lifetime pertaining to the vibrationally unrelaxed triplet was found to be 470 +- 50 ns. Measurement of a component of the photoion signal due to ...

We report a fully ab initio implementation of exterior complex scaling in B-splines to evaluate total, singly and triply differential cross sections in double photoionization problems. Results for He and H{sub 2} double photoionization are presented and compared with experiment.

. Abstract. � We calculate the photo-ionization cross-section from the ground state of the helium atom, using - Eg - �h , (4) #12;b. gremaud et al.: photo-ionization of the helium atom etc. 365 Fig. 1. � Positions will be amplified at higher energies. #12;b. gremaud et al.: photo-ionization of the helium atom ...

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

... Title : High Resolution Absolute Absorption Cross Sections of NO2 at 295, 573, and 673K at Visible Wavelengths: Comprehensive Data Tables. ...

Cometary X-ray Emission Spectra and Absolute Charge-Exchange cross Sections ... Also reported were absolute single, double, and triple charge-exchange cross ...

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

Partial photoionization cross sections of atoms and ions from He to Zn for all subshells nl of ground-state species are calculated with the Hartree-Dirac-Slater method for photon energies E [le] 100 E[sub th], where E[sub th] is the photoionization threshold. The cross sections are fitted by simple analytic ...

We use Hartree-Slater self-consistent-field wave functions to compute photoionization and photorecombination cross sections and rates for partially ionized iron atoms, both in their isolated state and in a plasma environnment. The calculated cross sections are fitted to analytic expressions so that the ...

We have measured the double-to-single photoionization ratio of beryllium (1s{sup 2}2s{sup 2}) between 28 and 40 eV and determined the relative single- and double-photoionization cross sections. In this energy region only simultaneous but not sequential emission of both 2s electrons can take place. We also compare our data with recent ...

Relativistic and resonance effects in the photoionization of Mg-like Fe XV are investigated using the Breit-Pauli R-matrix method at near-threshold and intermediate energies, complemented by the relativistic random-phase approximation and multichannel quantum-defect theory in the energy region up to the L-shell ionization thresholds. The cross sections ...

A high efficiency photoionization detector is described using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel ...

A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector ...

A prototype spectrometer has been developed for space applications requiring long term absolute EUV photon flux measurements. The energy spectrum of the incoming photons is transformed directly into an electron energy spectrum by taking advantage of the p...

We experimentally demonstrate a detection scheme suitable for state analysis of single optically trapped atoms in less than 1 ?s with an overall detection efficiency ? exceeding 98%. The method is based on hyperfine-state-selective photoionization and subsequent registration of the correlated photoion-electron pairs by coincidence counting via two opposing ...

Atomic Data News. Atomic data news. Iron K shell photoionization cross sections. ADAS Dielectronic Recombination (Badnell). Iron M shell UTA data (Gu). ...

Atomic Data News. Atomic data news. Iron K shell photoionization cross sections. ADAS Dielectronic Recombination (Badnell). Iron M shell UTA data (Gu). ...

A calculation of the two X-ray K-shell photoionization cross section of chlorine will be presented and the feasibility of an experiment will be discussed.

A calculation of the two X-ray K-shell photoionization cross section of chlorine will be presented and the feasibility of an experiment will be discussed.

... The photoabsorption cross sections and photoionization yields of N,N-dimethylaniline, triethylamine, trimethylamine, and tri-n- propylamine are ...