Ionized Molecular Hydrogen Build-Up and Confinement Inside the Space Charge of a Continually Resupplied Electron Cloud

The adiabatic nuclei approximation is used to study low energy positron collisions with hydrogen molecules. The interaction of the positrons with the hydrogen molecules is represented as a superposition of electrostatic and polarization potentials. Total and differential elastic and momentum transfer cross sections are calculated. The effect of small variations in the potentials, and the convergence of the partial wave expansion are discussed. The annihilation rate of the positrons is calculated with and without incorporating the effect of distortion of the electron cloud by the incoming positrons. Rotational excitation cross sections, both differential and total, are presented. The results are compared, where possible, to recent similar two-center calculations of Hara, and experimental results of Coleman et al.

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Review of some important beam physics issues in electron–positron collider designs

Modern Physics Letters A ◽

10.1142/s0217732315300062 ◽

2015 ◽

Vol 30 (11) ◽

pp. 1530006 ◽

Cited By ~ 6

Author(s):

Jie Gao

Keyword(s):

Space Charge ◽

Electron Cloud ◽

Collective Effects ◽

Linear Electron ◽

Scientific Publications ◽

Beam Physics ◽

Charge Effects ◽

Electron Positron ◽

Linear Colliders ◽

Dynamic Aperture

In this paper, we will give a brief review of some important beam physics in circular and linear electron–positron collider designs, covering beam–beam tune limits, longitudinal and transverse single bunch collective effects, electron cloud and space charge effects, dynamic aperture estimations, etc. The main feature of this review is that the corresponding beam physics treatments are coming from author's previous research works which are scattered in different scientific publications both for circular and linear colliders. With the progresses of future linear colliders, such as ILC, and future circular electron–positron colliders, such as CEPC, it is high time to review the key beam physics issues in the optimization designs of these two kinds of machines.

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Analytical treatment of the nonlinear electron cloud effect and the combined effects with beam-beam and space charge nonlinear forces in storage rings

Chinese Physics C ◽

10.1088/1674-1137/33/2/012 ◽

2009 ◽

Vol 33 (2) ◽

pp. 135-144

Author(s):

Gao Jie

Keyword(s):

Space Charge ◽

Storage Rings ◽

Electron Cloud ◽

Combined Effects ◽

Analytical Treatment ◽

Cloud Effect

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To What Extent are Inelastically Scattered Electrons Useful in the Stem?

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071879 ◽

1973 ◽

Vol 31 ◽

pp. 286-287 ◽

Cited By ~ 2

Author(s):

H. Rose

Keyword(s):

Electron Microscope ◽

High Resolution ◽

Electron Correlation ◽

Quantum Noise ◽

Collection Efficiency ◽

Scanning Transmission Electron Microscope ◽

Electron Cloud ◽

Scanning Time ◽

Transmission Electron ◽

Scanning Transmission

The scanning transmission electron microscope offers the possibility of utilizing inelastically scattered electrons. Use of these electrons in addition to the elastically scattered electrons should reduce the scanning time (dose) Which is necessary to keep the quantum noise below a certain level. Hence it should lower the radiation damage. For high resolution, Where the collection efficiency of elastically scattered electrons is small, the use of Inelastically scattered electrons should become more and more favorable because they can all be detected by means of a spectrometer. Unfortunately, the Inelastic scattering Is a non-localized interaction due to the electron-electron correlation, occurring predominantly at the circumference of the atomic electron cloud.

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Electron holography of interfaces in electroceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151271 ◽

1993 ◽

Vol 51 ◽

pp. 1088-1089

Author(s):

Vinayak P. Dravid ◽

V. Ravikumar ◽

Richard Plass

Keyword(s):

Space Charge ◽

Direct Evidence ◽

Materials Science ◽

Theoretical Work ◽

Electron Holography ◽

Resolution Limit ◽

Interference Phenomenon ◽

X Ray ◽

Electron Sources ◽

Science Community

With the advent of coherent electron sources with cold field emission guns (cFEGs), it has become possible to utilize the coherent interference phenomenon and perform “practical” electron holography. Historically, holography was envisioned to extent the resolution limit by compensating coherent aberrations. Indeed such work has been done with reasonable success in a few laboratories around the world. However, it is the ability of electron holography to map electrical and magnetic fields which has caught considerable attention of materials science community.There has been considerable theoretical work on formation of space charge on surfaces and internal interfaces. In particular, formation and nature of space charge have important implications for the performance of numerous electroceramics which derive their useful properties from electrically active grain boundaries. Bonnell and coworkers, in their elegant STM experiments provided the direct evidence for GB space charge and its sign, while Chiang et al. used the indirect but powerful technique of x-ray microchemical profiling across GBs to infer the nature of space charge.

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