Photoemitters Based on Glass - ITO Structures

1999 ◽  
Vol 588 ◽  
Author(s):  
J. Olesik
Keyword(s):  
Pulse Amplitude ◽  
Field Method ◽  
Internal Electric Field ◽  
Electron Multiplier ◽  
Amplitude Spectra ◽  
Field Electrode ◽  
Amplitude Analyzer ◽  
Dynamics Simulations ◽  
Photoinduced Changes ◽  
Reactive Ion Sputtering

AbstractThe sample was a silicon glass with conducting films (ITO) evaporated by reactive ion sputtering on its both sides. The internal electric field was created by applying a negative polarizing voltage Upol, to field electrode. The investigations were performed in the vacuum of the order 10−6 Pa. As a result of applying Upol and illumination, photoelectrons are released and enter electron multiplier. The electrons create voltage pulses in the multiplier which are recorded in the multichannel pulse amplitude analyzer. The amplitude spectra were measured for unilluminated samples and illuminated by a quartz lamp.Energy analysis of emitted electrons was performed by the retarding field method. Measurements of electrons energy in field induced emission showed that about 80% o electrons have energy up to 10 eV but some electrons of higher energy are also detected. The described effects can be modeled with support of the electron effects occurring during the intrinsic discharges in gases. Theoretical molecular dynamics simulations have shown that SnO4 tetrahedral interacting with SiO4 clusters of the glass substrate play central role in the observed nonlinear photoinduced changes.

Two-dimensional 1024 channel pulse amplitude analyzer (DMA-1024)

Atomic Energy ◽  
1962 ◽  
Vol 11 (1) ◽  
pp. 694-695
Author(s):  
A. A. Rostovtsev ◽  
Yu. I. Il'in ◽  
A. S. Beregovskii ◽  
V. G. Tishin ◽  
V. E. Zezyulin ◽  
...  
Keyword(s):  
Pulse Amplitude ◽  
Two Dimensional ◽  
Amplitude Analyzer

Phase Field Method

2006 ◽  
Author(s):  
Vasily Bulatov ◽  
Wei Cai
Keyword(s):  
Phase Field ◽  
Degrees Of Freedom ◽  
Computer Code ◽  
Field Method ◽  
Dislocation Dynamics ◽  
Phase Field Method ◽  
Transform Method ◽  
Computational Mathematics ◽  
Dynamics Simulations ◽  
General Aspects

The phase field method (PFM) can be used as an approach to dislocation dynamics simulations alternative to the line DD method discussed in Chapter 10. The degrees of freedom in PFM are continuous smooth fields occupying the entire simulation volume, and dislocations are identified with locations where the field values change rapidly. As we will see later, as an approach to dislocation dynamics simulations PFM holds several advantages. First, it is easier to implement into a computer code than a line DD model. In particular, the complex procedures for making topological changes (Section 10.4) are no longer necessary. Second, the implementation of PFM can take advantage of well-developed and efficient numerical methods for solving partial differential equations (PDEs). Another important merit of PFM is its applicability in a wide range of seemingly different situations. For example, it is possible to simulate the interaction and co-evolution of several types of material microstructures, such as dislocations and alloying impurities, within a unified model. PFM has become popular among physicists and materials scientists over the last 20 years, but as a numerical method it is not new. After all, it is all about solving PDEs on a grid. Numerical integration of PDEs is a vast and mature area of computational mathematics. A number of efficient methods have already been developed, such as the finite difference method [121], the finite element method [122], and spectral methods [123], all of which have been used in PFM simulations. The relatively new aspects of PFM are associated with the method’s formulation and applications, which are partly driven by the growing interest in understanding material microstructures. In Section 11.1, we begin with the general aspects of PFM demonstrated by two simple applications of the method not related to dislocations. Section 11.2 describes the elements required to adapt PFM to dislocation simulations. There we will briefly venture into the field of micromechanics and consider the concept of eigenstrain. The elastic energy of an arbitrary eigenstrain field is derived in Section 11.3. Section 11.4 discusses an example in which the PFM equations for dislocations are solved using the fast Fourier transform method.

scholarly journals Branching Corrected Mean Field Method for Nonadiabatic Dynamics

2020 ◽  
Author(s):  
Jiabo Xu ◽  
Linjun Wang
Keyword(s):  
Potential Energy Surfaces ◽  
Quantum Dynamics ◽  
High Efficiency ◽  
Mean Field ◽  
Field Method ◽  
Model Systems ◽  
Nonadiabatic Dynamics ◽  
Model Base ◽  
Dynamics Simulations ◽  
Energy Surfaces

When describing nonadiabatic dynamics based on trajectories, severe trajectory branching occurs when the nuclear wave packets on some potential energy surfaces are reflected while those on the remaining surfaces are not. As a result, the traditional Ehrenfest mean field (EMF) approximation breaks down. In this study, two versions of the branching corrected mean field (BCMF) method are proposed. Namely, when trajectory branching is identified, BCMF stochastically selects either the reflected or the non-reflected group to build the new mean field trajectory or splits the mean field trajectory into two new trajectories with the corresponding weights. As benchmarked in six standard model systems and an extensive model base with two hundred diverse scattering models, BCMF significantly improves the accuracy while retaining the high efficiency of the traditional EMF. In fact, BCMF closely reproduces the exact quantum dynamics in all investigated systems, thus highlighting the essential role of branching correction in nonadiabatic dynamics simulations of general systems.

Dielectric properties of liquid phase molecular clusters using the external field method: molecular dynamics study

2014 ◽  
Vol 16 (27) ◽  
pp. 13943-13947 ◽  
Author(s):  
Chathurika D. Abeyrathne ◽  
Malka N. Halgamuge ◽  
Peter M. Farrell ◽  
Efstratios Skafidas
Keyword(s):  
Molecular Dynamics ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electric Fields ◽  
Field Method ◽  
Molecular Clusters ◽  
Reaction Field ◽  
External Electric Fields ◽  
Properties Of Materials ◽  
Dynamics Simulations

A method based on molecular dynamics simulations is presented to determine dielectric properties of materials under external electric fields without prior knowledge of their static dielectric constant, using reaction field approximations.

Research on Multi-channel Pulse Amplitude Analyzer Based on FPGA

2021 ◽  
pp. 50-58
Author(s):  
Han Deng ◽  
Chong Wang ◽  
Shuang Xie ◽  
Aishan Mai ◽  
Weihong Huang ◽  
...  
Keyword(s):  
Pulse Amplitude ◽  
Amplitude Analyzer
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