• Title/Summary/Keyword: X-ray interferometer

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Study on Talbot Pattern for Grating Interferometer (격자간섭계를 위한 탈봇 패턴 연구)

  • Kim, Youngju;Oh, Ohsung;Kim, Jongyul;Lee, Seung Wook
    • Journal of radiological science and technology
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    • v.38 no.1
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    • pp.39-49
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    • 2015
  • One of properties which X-ray and Neutron can be applied nondestructive test is penetration into the object with interaction leads to decrease in intensity. X-ray interaction with the matter caused by electrons, Neutron caused by atoms. They share applications in nondestructive test area because of their similarities of interaction mechanism. Grating interferometer is the one of applications produces phase contrast image and dark field image. It is defined by Talbot interferometer and Talbot-Lau interferometer according to Talbot effect and Talbot-Lau effect respectively. Talbot interferometer works with coherence beam like X-ray, and Talbot-Lau has an effect with incoherence beam like Neutron. It is important to expect the interference in grating interferometer compared normal nondestructive system. In this paper, simulation works are conducted according to Talbot and Talbot-Lau interferometer in case of X-ray and Neutron. Variation of interference intensity with X-ray and Neutron based on wave theory is constructed and calculate elements consist the system. Additionally, Talbot and Talbot-Lau interferometer is simulated in different kinds of conditions.

System Design and Evaluation of a Compact and High Energy X-ray Talbot-Lau Grating Interferometer for Industrial Applications

  • Lee, Seho;Oh, Ohsung;Kim, Youngju;Lee, Seung Wook;Kim, Insoo;Kim, Jinkyu
    • Journal of the Korean Physical Society
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    • v.73 no.12
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    • pp.1827-1833
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    • 2018
  • X-ray grating interferometry has been an active area of research in recent years. In particular, various studies have been carried out for the practical use of the x-ray grating interferometer in medical and industrial fields. For the commercialization of the system, it needs to be optimized for its application. In this study, we have developed a prototype of the compact high energy x-ray grating interferometer of which the high effective energy and compactness is of our primary feature of design. We have designed the Talbot-Lau x-ray interferometer in a symmetrical geometry with an effective energy of 54.3 keV. The system has a source-to-analyzer grating distance of 788.4 mm, which is compact enough for a commercial product. In a normal operation, it took less than ten seconds to acquire a set of phase stepping images. The acquired images had a maximum visibility of about 15%, which is relatively high compared with the visibilities of the other high-energy grating interferometric systems reported so far.

Final Diffraction Patterns of the Beam Splitters used in the Soft XRay Interferometer by a He-Ne Laser

  • Oh, Chul-Han;Choi, Dae-Uk;Park, Sung-Jin;Howells, M.R.;Moller, E.J.
    • Journal of the Optical Society of Korea
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    • v.4 no.1
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    • pp.7-10
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    • 2000
  • The soft x-ray(10nm-100nm) interferometer is a modified Mach-Zehnder type interferometer and it consists of two beam-splitters and four totally reflecting mirrors. The beam-splitters used here are 50% transmission and 50% reflection grating type. The diffraction patterns of beam splitters(1st B.S.) were investigated with a He-Ne laser. The diffraction patterns produced by the soft x-ray interferometer (2nd B.S.) were also investigated in intensities positions. The diffraction patterns of 20 degree grazing incidence on the beam splitters(1st B.S.) show a circular array of spots. Both the reflected and the transmitted beams show the same patterns but symmetric circles on the screen. The maximum intensity appears roughly when n is in the zeroth and odd orders and the suppressed peak(missing order) appears when n is in even orders. Intensities of 3 center fringes(n = 0, $\pm$1) are stronger than others. These results confirm the reduced grating equation and make agree with the intensity distribution function. It was found that the final patterns produced by the soft x-ray interferometer (2nd B.S.) consisted of fine fringes which were caused by two of three diffraction beams that were arrived at the second beam-splitter.

Two Dimensional Atomic Force Microscope (서브나노급 정밀도의 2 차원 원자현미경 개발)

  • Lee, Dong-Yeon;Gweon, Dae-Gab
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1778-1783
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    • 2008
  • A compact and two-dimensional atomic force microscope (AFM) using an orthogonal sample scanner, a calibrated homodyne laser interferometer and a commercial AFM head was developed for use in the nanometrology field. The x and y position of the sample with respect to the tip are acquired by using the laser interferometer in the open-loop state, when each z data point of the AFM head is taken. The sample scanner which has a motion amplifying mechanism was designed to move a sample up to $100{\times}100{\mu}m^2$ in orthogonal way, which means less crosstalk between axes. Moreover, the rotational errors between axes are measured to ensure the accuracy of the calibrated AFM within the full scanning range. The conventional homodyne laser interferometer was used to measure the x and y displacements of the sample and compensated via an X-ray interferometer to reduce the nonlinearity of the optical interferometer. The repeatability of the calibrated AFM was measured to sub-nm within a few hundred nm scanning range.

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Atomic Force Microscope for Standard Length Metrology (직교 스캐너와 레이저 간섭계를 사용한 교정용 원자현미경)

  • Lee, Dong-Yeon;Kim, Dong-Min;Gweon, Dae-Gab
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.12 s.255
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    • pp.1611-1617
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    • 2006
  • A compact and two-dimensional atomic force microscope (AFM) using an orthogonal sample scanner, a calibrated homodyne laser interferometer and a commercial AFM head was developed for use in the nano-metrology field. The x and y position of the sample with respect to the tip are acquired by using the laser interferometer in the open-loop state, when each z data point of the AFM head is taken. The sample scanner which has a motion amplifying mechanism was designed to move a sample up to $100{\times}100{\mu}m^2$ in orthogonal way, which means less crosstalk between axes. Moreover, the rotational errors between axes are measured to ensure the accuracy of the calibrated AFM within the full scanning range. The conventional homodyne laser interferometer was used to measure the x and y displacements of the sample and compensated via an X-ray interferometer to reduce the nonlinearity of the optical interferometer. The repeatability of the calibrated AFM was measured to sub-nm within a few hundred nm scanning range.

Displacement measurement in nanometer region and calibration of transducers using combined optical and x-ray interferometer (광/엑스선 복합간섭계를 이용한 나노미터 영역의 변위 측정 및 trnasducer의 비선형 교정)

  • Park Jin-Won;Jo Jae-Gun;Byun Sang-Ho;Eom Cheon-Il
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.515-518
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    • 2005
  • 현재 정밀한 길이를 측정하기 위해서는 광 간섭계를 이용한 측정기술이 주로 사용되어지고 있다. 이러한 광 간섭계의 발전과 더불어 이보다 더 높은 분해능을 얻기 위해 광파장보다 1000배 정도 짧은 엑스선을 이용한 변위 측정 기술개발이 진행되고 있다. 본 연구에서는 이러한 엑스선을 이용한 간섭계를 제작하고, 광 간섭계와 결합된 광/엑스선 복합간섭계를 구성하여 광 간섭계가 안고 있는 자체의 비선형성이 제거된 정밀 변위 측정 시스템을 구성하였다. 그 응용으로써, 제작된 광/엑스선 복합간섭계를 이용하여 나노미터 영역에 서 사용하는 transducer의 비선형성을 측정하였다.

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Nanometrological Application of X-ray Interferometry (엑스선 간섭계를 이용한 초정밀측정)

  • 엄천일
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.6
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    • pp.40-45
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    • 2000
  • 교정은 모든 측정분야에서 어렵고 까다로운 주제인데, 특히 정전센서, 레이저간섭계, AFM, STM 등을 포함하는 나노메트롤로지(nanometrology : 나노측정) 분야에서는 그러하다. 나노측정에서는 전체 측정범위가 센서들의 한계분해능 값과 비슷한데, 이러한 측정에서 높은 소급성을 유지하기는 매우 어렵기 때문이다.(중략)

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