Development of length standard phantom for length measurement correction in x-ray image

2021 ◽  
Vol 92 (8) ◽  
pp. 084104
Author(s):  
Hyo-Min Cho ◽  
Changwoo Lee ◽  
Hojae Kim ◽  
Yong Tae Kim ◽  
Teo Jeon Shin ◽  
...  
2017 ◽  
Vol 11 (5) ◽  
pp. 707-715 ◽  
Author(s):  
Kazuya Matsuzaki ◽  
◽  
Osamu Sato ◽  
Hiroyuki Fujimoto ◽  
Makoto Abe ◽  
...  

X-ray computed tomography systems (X-ray CT) designed for metrological use are frequently used in the manufacturing industry. This is because X-ray CT is able to measure not only outer geometry but also inner geometry nondestructively and relatively quickly. However, X-ray CT in the state of the art is not always able to demonstrate its measurement performance and traceability to SI. One of problems is that it is hard to evaluate error sources unique to X-ray CT, such as scattering and beam hardening, called as “material influence.” The hypothesis to the mechanism of Bi-directional length measurement error from the material influence is proposed. The hypothesis is that Bi-directional length measurement error is mainly caused by the form measurement error of a small feature on the gauge. The form measurement error of a small feature on the gauge is dominantly influenced by beam hardening. The hypothesis is validated through actual experiments and simulations. The results of the experiments and corresponding simulations lead us to the conclusion that the magnitude of the form measurement error of a small feature on a rotational asymmetric gauge is clearly correlated with a location of the small feature on the gauge.


2011 ◽  
Vol 35 (5) ◽  
pp. 505-508
Author(s):  
Ying-Chao Du ◽  
Jian-Fei Hua ◽  
Li-Xin Yan ◽  
Qiang Du ◽  
Wen-Hui Huang ◽  
...  

1993 ◽  
Vol 18 (8) ◽  
pp. 646 ◽  
Author(s):  
M. H. Sher ◽  
T. J. McIlrath ◽  
U. Mohideen ◽  
H. W. K. Tom ◽  
O. R. Wood ◽  
...  

1993 ◽  
Author(s):  
Mark Sher ◽  
Umar Mohideen ◽  
Harry W. Tom ◽  
Obert R. Wood II ◽  
Gary D. Aumiller ◽  
...  

1994 ◽  
Author(s):  
Harry W. Tom ◽  
Mark Sher ◽  
Umar Mohideen ◽  
Obert R. Wood II ◽  
Gary D. Aumiller ◽  
...  

Author(s):  
M. H. Sher ◽  
U. Mohideen ◽  
H. W. K. Tom ◽  
O. R. Wood ◽  
G. D. Aumiller ◽  
...  

2014 ◽  
Vol 625 ◽  
pp. 322-325
Author(s):  
Dong Wei ◽  
Kiyoshi Takamasu ◽  
Hirokazu Matsumoto

High-precision length measurements are strongly demanded for not only industry requirements and science purposes.In 2009, a femtosecond optical frequency comb (FOFC) was adopted in Japan as the national standard tool for measuring length. Recently, numerous studies have focused on FOFC-based high-precision length measurement because this approach offers the possibility of development of a ultimate green length traceability system. A single-wavelength helium–neon (He–Ne) laser was used as a length standard. An FOFC emits discrete pulse-train-shaped light. This markedly different characteristic exists between a He-Ne laser and an FOFC is the reason for the challenge. Previous attempts to challenge this problem have not been satisfactory. This has limited the development and applications of FOFC-based length measurement. In this work, we review our efforts of FOFC-based high-precision length measurement toward developing an ultimate green length traceability system.


2009 ◽  
Vol 33 (S2) ◽  
pp. 161-164 ◽  
Author(s):  
Shi Jia-Ru ◽  
Chen Huai-Bi ◽  
Tang Chuan-Xiang ◽  
Huang Wen-Hui ◽  
Du Ying-Chao ◽  
...  

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.


1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.


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