Numerical and analytical models of gain saturation in microchannel plate devices

Author(s):  
Michele Bassan ◽  
Leonardo Giudicotti ◽  
Roberto Pasqualotto ◽  
Andrea Sardella
2017 ◽  
Vol 46 (10) ◽  
pp. 1003005 ◽  
Author(s):  
谢运涛 Xie Yuntao ◽  
张玉钧 Zhang Yujun ◽  
王 玺 Wang Xi ◽  
孙晓泉 Sun Xiaoquan

1997 ◽  
Author(s):  
Leonardo Giudicotti ◽  
Michele Bassan ◽  
Roberto Pasqualotto ◽  
Andrea Sardella

2016 ◽  
Vol 87 (7) ◽  
pp. 073303 ◽  
Author(s):  
Qiangqiang Wang ◽  
Zheng Yuan ◽  
Zhurong Cao ◽  
Bo Deng ◽  
Tao Chen ◽  
...  

1994 ◽  
Vol 65 (1) ◽  
pp. 247-258 ◽  
Author(s):  
L. Giudicotti ◽  
M. Bassan ◽  
R. Pasqualotto ◽  
A. Sardella

Author(s):  
James F. Mancuso ◽  
Leo A. Fama ◽  
William B. Maxwell ◽  
Jerry L. Lehman ◽  
Hasso Weiland ◽  
...  

Micro-diffraction based crystallography is essential to the design and development of many classes of ‘crafted materials’. Although the scanning electron microscope can provide crystallographic information with high spatial resolution, its current utility is severely limited by the low sensitivity of existing diffraction techniques (ref: Dingley). Previously, Joy showed that energy filtering increased contrast and pattern visibility in electron channelling. This present paper discribes the effect of energy filtering on EBSP sensitivity and backscattered SEM imaging.The EBSP detector consisted of an electron energy filter, a microchannel plate detector, a phosphor screen, optical coupler, and a slow scan CCD camera. The electrostatic energy filter used in this experiment was constructed as a cone with 5 coaxial electrodes. The angular field-of-view of the filter was approximately 38°. The microchannel plate, which was the initial sensing component, had high gain and had 50% to 80% detection efficiency for the low energy electrons that passed through the retarding field filter.


Author(s):  
Galen Powers ◽  
Ray Cochran

The capability to obtain symmetrical images at voltages as low as 200 eV and beam currents less than 9 pico amps is believed to be advantageous for metrology and study of dielectric or biological samples. Symmetrical images should allow more precise and accurate line width measurements than currently achievable by traditional secondary electron detectors. The low voltage and current capability should allow imaging of samples which traditionally have been difficult because of charging or electron beam damage.The detector system consists of a lens mounted dual anode MicroChannel Plate (MCP) detector, vacuum interface, power supplies, and signal conditioning to interface directly to the video card of the SEM. The detector has been miniaturized so that it does not interfere with normal operation of the SEM sample handling and alternate detector operation. Biasing of the detector collection face will either add secondaries to the backscatter signal or reject secondaries yielding only a backscatter image. The dual anode design allows A−B signal processing to provide topological information as well as symmetrical A+B images.Photomicrographs will show some of the system capabilities. Resolution will be documented with gold on carbon. Variation of voltage, beam current, and working distance on dielectric samples such as glass and photoresist will demonstrate effects of common parameter changes.


2020 ◽  
Vol 21 (6) ◽  
pp. 610
Author(s):  
Xiaoliang Cheng ◽  
Chunyang Zhao ◽  
Hailong Wang ◽  
Yang Wang ◽  
Zhenlong Wang

Microwave cutting glass and ceramics based on thermal controlled fracture method has gained much attention recently for its advantages in lower energy-consumption and higher efficiency than conventional processing method. However, the irregular crack-propagation is problematic in this procedure, which hinders the industrial application of this advanced technology. In this study, the irregular crack-propagation is summarized as the unstable propagation in the initial stage, the deviated propagation in the middle stage, and the non-penetrating propagation in the end segment based on experimental work. Method for predicting the unstable propagation in the initial stage has been developed by combining analytical models with thermal-fracture simulation. Experimental results show good agreement with the prediction results, and the relative deviation between them can be <5% in cutting of some ceramics. The mechanism of deviated propagation and the non-penetrating propagation have been revealed by simulation and theoretical analysis. Since this study provides effective methods to predict unstable crack-propagation in the initial stage and understand the irregular propagation mechanism in the whole crack-propagation stage in microwave cutting ceramics, it is of great significance to the industrial application of thermal controlled fracture method for cutting ceramic materials using microwave.


1996 ◽  
Vol 8 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Ken Bartley

This paper discusses the need for nationally based analytical models of the medieval period. The use of cluster analysis as a method for classifying demesne farms, by the crops they grew and their livestock management, is explained. Successful implementation of cluster analysis requires both the existence of a large base sample, to permit isolation of specific groupings within the data, and access to considerable processing time. The paper concludes by demonstrating how discriminant analysis can provide an efficient and systematic way of classifying even a single manor within a national frame of reference.


Sign in / Sign up

Export Citation Format

Share Document