• Title/Summary/Keyword: 광자빔

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Barium atomic beam generation and atomic velocity selection (복사가열방식 오븐에 의한 배리움 원자빔 발생과 공명 형광의 광자수 셈 방법에 의한 배리움 원자빔의 밀도 및 속도분포 측정)

  • 박상범;안경원
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.08a
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    • pp.72-73
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    • 2000
  • 단원자를 이용한 Cavity-QED 실험을 통해서 광자 수상태 및 sub-poissonian 광원 구현 및 비고 전적인 광 특성을 가지는 광원등을 구현 할 수 있다. 이를 위해서는 오랫동안 공진기 안에 포획하거나, 빔의 형태로 단원자들이 일정시간 동안 공진기를 지나게 해야 한다. 본 연구는 안정한 원자빔 속도제어 실험에 관한 것으로 자체 제작한 원자빔 오븐의 특성과 원자빔 속도 선택기의 제작, 속도 선택 결과에 대하여 논하고자 한다. (중략)

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Calculation Formula for Effective Photon Energy in kV X-ray Beam of Mammography (유방촬영의 kV X-선 빔에서 유효광자에너지에 대한 계산식)

  • Young-On Park;Sang-Hun Lee;Jong-Eon Kim
    • Journal of the Korean Society of Radiology
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    • v.17 no.4
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    • pp.507-514
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    • 2023
  • The purpose of this study is to find a formula that can easily calculate the effective photon energy in the X-ray beam of mammography. The tube voltage measured for each set tube voltage was obtained using the X2 MAM Sensor. The mass attenuation coefficient for aluminum of the aluminum filter was obtained from the half value layer measurement from each measured tube voltage X-ray beam. The mass attenuation coefficient of aluminum obtained from each measured tube voltage X-ray beam was corresponded to the mass attenuation coefficient of aluminum for each photon energy obtained from NIST. The photon energy corresponding to the matching mass attenuation coefficient was determined as the effective photon energy. The formula for calculating the determined effective photon energy was obtained by polynomial matching of the effective photon energy for each tube voltage in the Origin pro 2019b statistical program as y = 28.98968-1.91738x + 0.07786x2-0.000946717x3. Here, x is the measuring tube voltage and y is the effective photon energy. The calculation formula of the effective photon energy of the mammography X-ray beam obtained in this study is considered to be very useful in obtaining the interaction coefficient between the X-ray beam and a certain substance in clinical practice.

Hanbury brown-Twiss effect in a two-photon interference experiment (광자쌍을 이용한 Hanbury Brown-Twiss 실험)

  • Kim, Heon-Oh;Ko, Jeong-Hoon;Park, Goo-Dong;Kim, Tae-Soo
    • Korean Journal of Optics and Photonics
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    • v.14 no.2
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    • pp.130-134
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    • 2003
  • We present experimental observations of two-photon spatial bunching effect in a two-photon interference experiment by using the photon pairs produced by parametric down-conversion and the Hong-Ou-Mandel interferometer. We show that this pairing behavior is observed by coincidence detection, but gives a negligible effect for a single count.

Simulation of Temperature Distribution and Readout Signal of Magnetic Amplifying Magnetooptical System (도메인 확장형 광자기 디스크의 온도분포 및 재생신호 시뮬레이션)

  • Yang, Jae-Nam;Jo, Soon-Chul
    • Journal of the Korean Magnetics Society
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    • v.14 no.2
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    • pp.65-70
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    • 2004
  • Read out signal and temperature distribution of magnetic amplifying magnetooptical disk were studied. Temperature distribution of recording layer and adjacent layers were calculated when the disk was at rest. Mark size, length and location were simulated from a chain of recording beam pulses. In addition, signal amplitude depending on the shape of the marks, readout signals from the recording layer and amplified marks of the readout layer, were simulated. Simplified thermal conduction model was used to calculate the temperature distribution of recording and adjacent layers as a function of time as well as to calculate the mark size, length and location. Readout signal was calculated by the convolution of the disk reflectivity and the Gaussian beam intensity. Readout signal from the mark in the readout layer amplified to the size of the laser beam fumed out to be twice as large as the signal from the crescent shaped mark in the recording layer.

Calibration of Optically Stimulated Luminescent nanoDot Dosimeter for 6 MV Photon Beam (6 MV 광자 빔에 대한 광자극형광나노닷선량계의 교정)

  • Kim, Jongeon;Kim, Seonghu;Lee, Hyoyeong
    • Journal of the Korean Society of Radiology
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    • v.7 no.1
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    • pp.93-98
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    • 2013
  • The purpose of this study is to investigate the calibration of an optically stimulated luminescent nanoDot dosimeter(OSLnD) to 6 MV photon beam. Dose ranges of the calibration of linear and non-linear from the analysis of dose response of the OSLnD were decided. To evaluate the accuracy of calibration equation and the calibration, the sets of the calibration and quality control dosimeter were used to make. The calibrations were performed by the linear and the non-linear in the dose range of 0~300 cGy and 20~1300 cGy, respectively. The errors of the calibration were acquired less than 0.1% respectively from the measurement of the quality control dosimeters for the calibration of linear and the non-linear. This study provides the calibration equation of the OSLnD to the 6 MV photon beam.

The fourth-order interference between entangled state photon pairs with different frequencies (진동수가 서로 다른 얽힘상태 광자쌍의 4차 간섭)

  • Kim, Heon-Oh;Ko, Jeong-Hoon;Kim, Tae-Soo
    • Korean Journal of Optics and Photonics
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    • v.13 no.4
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    • pp.308-313
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    • 2002
  • One of the nonclassical effects in two-photon interference experiments, spatial quantum beating, is observed in fourth-order interference with pairs of photons produced by a spontaneous parametric down-conversion process. When photon pairs in different frequencies $\omega1$ and $\omega2$ are mixed together, and directed to two detectors, the coincidence counts exhibit a cosine modulation with difference frequency | $\omega1$- $\omega2$|. The measured coincidence counts turned out to have an interference pattern with periodicity of 10.45 ㎛ in position or 34.82fs in time delay, which corresponds to the period 2$\pi$/| $\omega1$- $\omega2$| for the beat frequency of 0.29${\times}10^{14}$Hz.

Application of Si-$SiO_2$ Based Two-Dimension Photonic Crystal Waveguides (Si-$SiO_2$ 기반 2차원 광자결정 도파로의 응용)

  • Yeo, Jong-Bin;Kim, Jun-Hyung;Im, Woo-Sik;Lee, Eun-Sun;Lee, Hyun-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.465-466
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    • 2006
  • 서로 다른 굴절률을 갖는 유전재료를 주기적으로 배열함으로써 광자금지대(PBG)를 형성시킬 수 있는 2 차원(2D)광자결정배열에 선결함(line defects)을 줌으로써 기존의 평판형광도파로(PLC)와는 다른 개념의 광자결정도파로를 제작할 수 있다. 특히, 광자결정도파로는 급격한 굽힘(bending)에도 저손실의 효과를 갖도록 할 수 있기 때문에 광집적회로에 효과적으로 적용된다. 본 연구에서는 정방형 격자구조의 2차원 광자결정에 대한 광자밴드구조를 구하고 이로부터 추출된 구조매개변수를 이용하여 광자결정도파로를 설계하고 그의 특성을 평가하였다. 특히, 광자결정도파로와 PLC형도파로 특성을 비교하였다. 설계된 광자결정 도파로를 전자빔 및 홀로그래픽 리소그라피를 이용하여 제작, 평가할 것이다.

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