Ion Beam Figuring Fabricate Effect with Different Removal Sizes

2013 ◽  
Vol 552 ◽  
pp. 142-146
Author(s):  
Yong Qiang Gu
Keyword(s):  
Spatial Frequency ◽  
Ion Beam ◽  
Influence Factors ◽  
Frequency Range ◽  
Surface Errors ◽  
Power Spectral ◽  
The Difference ◽  
Lens Surface ◽  
Ion Beam Figuring

Ion Beam Figure (IBF) is believed to be one of the most effective technics that can fabricate lens with nano or even sub-nano accuracy. For different sizes of IBF removal functions, the correct effects in different spatial frequency range are different. Power Spectral Density (PSD) curve can describe surface errors in full spatial frequency range, so it is a very convenient way to evaluate the quality of lens’ surface. In this paper, firstly, the principles of IBF and PSD are introduced briefly; Secondly, IBF removal functions with sizes from 2 mm to 15 mm are generated. A lens with surface error more than PV value 400nm is simulated with different sizes of IBF removal functions by Lucy-Richardson algorithm. Finally, experiments are done by IBF plant. A lens is fabricated by different sizes of removal functions and the fabricate results are tested by interferometer precisely and calculated to PSD curves. By the comparison of these curves, the IBF fabricate effects with different removal sizes are analyzed, which show that the smaller the removal size, the better the removal effect in higher spatial frequency range, but in the meantime, it will take a much longer time. Also the reasons of the difference between theory simulation and actual fabrication result are taken into account, and several influence factors are analyzed.

How Xe and Ga FIB Differ in Inducing Lateral Damage on TEM Samples

2015 ◽  
Author(s):  
Tomáš Hrnčíř ◽  
Jozef Vincenc Oboňa ◽  
Martin Petrenec ◽  
Jan Michalička ◽  
Christian Lang
Keyword(s):  
Sample Preparation ◽  
Analytical Methods ◽  
Beam Energy ◽  
Ion Beam ◽  
Semiconductor Devices ◽  
Amorphous Layer ◽  
Sample Structure ◽  
The Difference ◽  
Final Cleaning

Abstract Reducing FIB induced damage on TEM samples is very important in order to preserve the sample structure, especially on modern semiconductor devices. We have compared the damage caused by Ga ion beam to our measurements of the damage caused by Xe ion beam and came to the conclusion that Xe ion beam induced damage is significantly lower at 30 keV beam energy. This has been proven by several independent analytical methods. Our results show that TEM sample preparation by Xe ion beam causes less amorphous damage and increase the quality of the lamella and in many cases it will allow to prepare the lamella by finishing it even at 30 keV, without the final cleaning step at the low beam energy. Final polishing step by Xe beam at beam energy 3 keV further reduces the amorphous layer, but the difference against Ga beam is not so significant like at 30 keV.

scholarly journals Detecting of the Longitudinal Grouting Quality in Prestressed Curved Tendon Duct Using Piezoceramic Transducers

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1212 ◽  
Author(s):  
Tianyong Jiang ◽  
Bin He ◽  
Yaowen Zhang ◽  
Lei Wang
Keyword(s):  
Lead Zirconate Titanate ◽  
Wavelet Packet ◽  
Lead Zirconate ◽  
Stress Waves ◽  
Longitudinal Plane ◽  
Power Spectral ◽  
Experimental Process ◽  
The Difference ◽  
Grouting Materials

To understand the characteristics of longitudinal grouting quality, this paper developed a stress wave-based active sensing method using piezoceramic transducers to detect longitudinal grouting quality of the prestressed curved tendon ducts. There were four lead zirconate titanate (PZT) transducers installed in the same longitudinal plane. One of them, mounted on the bottom of the curved tendon duct, was called as an actuator for generating stress waves. The other three, pasted on the top of the curved tendon duct, were called as sensors for detecting the wave responses. The experimental process was divided into five states during the grouting, which included 0%, 50%, 75%, 90%, and 100% grouting. The voltage signals, power spectral density (PSD) energy and wavelet packet energy were adopted in this research. Experimental results showed that all the amplitudes of the above analysis indicators were small before the grouting reached 90%. Only when the grouting degree reached the 100% grouting, these parameters increased significantly. The results of different longitudinal PZT sensors were mainly determined by the distance from the generator, the position of grouting holes, and the fluidity of grouting materials. These results showed the longitudinal grouting quality can be effectively evaluated by analyzing the difference between the signals received by the PZT transducers in the curved tendon duct. The devised method has certain application value in detecting the longitudinal grouting quality of prestressed curved tendon duct.

Analysis of Public Transportation Competitiveness Based on Potential Passenger Travel Intentions: Case Study in Shanghai, China

2019 ◽  
Vol 2673 (4) ◽  
pp. 823-832 ◽  
Author(s):  
Linbo Li ◽  
Mengfei Cao ◽  
Yufang Bai ◽  
Ziqi Song
Keyword(s):  
Service Quality ◽  
Public Transportation ◽  
Development Policy ◽  
Influence Factors ◽  
Passenger Travel ◽  
The Difference ◽  
The Cost ◽  
Car Travel

The primary goal of this paper is to identify the influence factors of public transportation (PT) competitiveness as related to potential passengers through an analysis of travel intentions. The logistic regression model is utilized to analyze PT travel intentions of people who commute daily by car in Shanghai, China. Through comparing the service quality of PT and of car from five aspects (i.e., comfort, timeliness, reliability, economics, and safety), the significant influence factors are identified. The results reveal that the difference in service quality between PT travel and car travel is insignificant for safety and convenience, while comfort, reliability, and economics matter most to the willingness to travel via PT. In addition, increasing the cost of car travel and improving the service quality of PT are both helpful in attracting car users to switch travel mode and enhancing PT competitiveness. The findings and suggestions will provide support to decisions in PT development policy making.

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