scholarly journals Dynamics of Single­ and Multi-photon Ionisation Processes in Molecules

1986 ◽  
Vol 39 (5) ◽  
pp. 761 ◽  
Author(s):  
V McKoy ◽  
SN Dixit ◽  
RL Dubs ◽  
DL Lynch
Keyword(s):  
Synchrotron Radiation ◽  
Cross Sections ◽  
Single Photon ◽  
Realistic Model ◽  
Dye Lasers ◽  
Linear Molecules ◽  
Dynamical Information

Single-photon ionisation and resonant multiphoton ionisation studies, which can now be carried out using synchrotron radiation and pulsed dye lasers respectively, are providing important dynamical information on molecular photoionisation. In this paper we discuss some results of our recent studies of several, single- and multi-photon ionisation processes in molecules. The results will be taken from our studies of (i) single-photon ionisation of linear molecules with emphasis on the role of shape and autoionising resonances on these cross� sections, (ii) photoionisation from oriented NiCO as a simple but realistic model of photoemission in adsorbate-substrate systems, and (iii) resonant multiphoton ionisation of H2.

scholarly journals Single-Photon Multiple Detachment in Fullerene Negative Ions: Absolute Ionization Cross Sections and the Role of the Extra Electron

2013 ◽  
Vol 111 (4) ◽  
Author(s):  
R. C. Bilodeau ◽  
N. D. Gibson ◽  
C. W. Walter ◽  
D. A. Esteves-Macaluso ◽  
S. Schippers ◽  
...  
Keyword(s):  
Cross Sections ◽  
Single Photon ◽  
Negative Ions ◽  
Ionization Cross ◽  
Extra Electron ◽  
Ionization Cross Sections

ON THE IMPLICATIONS OF CONFINEMENT

1992 ◽  
Vol 07 (22) ◽  
pp. 5607-5624 ◽  
Author(s):  
C.D. ROBERTS ◽  
A.G. WILLIAMS ◽  
G. KREIN
Keyword(s):  
Cross Sections ◽  
Gluon Condensate ◽  
Color Singlet ◽  
Primary Interest ◽  
Decomposition Property ◽  
Initial States ◽  
Dynamical Information

We consider some implications of confinement starting from the basic observation that cross-sections for the production of colored asymptotic states, such as free quarks and gluons, from color singlet initial states must be zero if QCD is to be confining. We discuss two pictures of confinement: the failure of the cluster decomposition property and the absence of a pole at timelike momenta in the propagator of a confined particle. We use QCD-based models as a framework to relate the failure of the cluster decomposition property to other ideas, such as the role of a nonzero gluon condensate. Our primary interest is to address the question of the absence of a mass pole through a study of model Schwinger-Dyson equations. These equations contain some of the dynamical information that is present in the study of the cluster decomposition property. We discuss the problems with this idea and its study using the Schwinger-Dyson equations.

Oxygen K near edge structures studied with multiple scattering calculations

1988 ◽  
Vol 46 ◽  
pp. 504-505
Author(s):  
Xudong Weng ◽  
Peter Rez
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Energy Window ◽  
Edge Structure ◽  
Fine Structures ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

An Study of Influence of Imperfections on the Delamination of Diamond-Like Carbon Films

2002 ◽  
Vol 719 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
Kyu Hwan Oh
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Imaging System ◽  
Ion Beam ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Glass Substrates ◽  
Atomic Force ◽  
Initiation And Propagation

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.

scholarly journals Role of α-Cluster Transfer in the Formation of 20Ne + 16O Cross-Sections at Backward Angles

2021 ◽  
Vol 51 (3) ◽  
pp. 780-787
Author(s):  
Sh. Hamada ◽  
Nourhan M. Elmedalaa ◽  
I. Bondouk ◽  
N. Darwish ◽  
Awad A. Ibraheem
Keyword(s):  
Cross Sections ◽  
Cluster Transfer

scholarly journals Few Body Effects in the Electron and Positron Impact Ionization of Atoms

Atoms ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 33
Author(s):  
R.I. Campeanu ◽  
Colm T. Whelan
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Differential Cross ◽  
Impact Ionization ◽  
Inert Gas ◽  
Interference Effects ◽  
Positron Impact ◽  
Competing Interactions ◽  
Energy Sharing

Triple differential cross sections (TDCS) are presented for the electron and positron impact ionization of inert gas atoms in a range of energy sharing geometries where a number of significant few body effects compete to define the shape of the TDCS. Using both positrons and electrons as projectiles has opened up the possibility of performing complementary studies which could effectively isolate competing interactions that cannot be separately detected in an experiment with a single projectile. Results will be presented in kinematics where the electron impact ionization appears to be well understood and using the same kinematics positron cross sections will be presented. The kinematics are then varied in order to focus on the role of distortion, post collision interaction (pci), and interference effects.

ANALYSIS OF THE ATOMIC Fe3d AND 4s PARTIAL CROSS SECTIONS IN THE REGION OF THE 3p → 3d GIANT RESONANCE

2002 ◽  
Vol 09 (02) ◽  
pp. 1229-1233 ◽  
Author(s):  
S. B. WHITFIELD ◽  
R. WEHLITZ ◽  
M. O. KRAUSE ◽  
C. D. CALDWELL
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Cross Sections ◽  
Systematic Study ◽  
Giant Resonance ◽  
Fitting Procedure

Using the technique of photoelectron spectrometry in conjunction with synchrotron radiation, we have carried out a systematic study of the partial cross sections of the main photoelectron lines arising from the ionization of the 3d and 4s subshells of atomic Fe in the vicinity of 3p → 3d autoionizing resonances. Our results confirm the presence of two broad and intense resonances which have been observed earlier. However, our high resolution results also clearly indicate the presence of numerous other weaker resonances. Through a fitting procedure we were able to accurately determine both resonance widths and positions.

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