Dr. Akifumi Koike Profile

Dr. Akifumi Koike

Researcher at ANSeeN Inc

SPIE Involvement:

Author

Publications (23)

Proceedings Article | 14 June 2023 Presentation

X-ray energy discrimination imaging by photon counting and the effect of x-ray energy on conventional energy-integrated imaging

Toru Aoki, Hiroki Kase, Katsuyuki Takagi, Akifumi Koike, Kento Tabata, Junichi Nishizawa

Proceedings Volume 12531, 125310K (2023) https://doi.org/10.1117/12.2663822

KEYWORDS: X-ray imaging, X-rays, Photon counting, X-ray detectors, Sensors, Image sensors, Target detection, Semiconductors, Photodetectors, Perovskite

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Proceedings Article | 1 September 2021 Poster + Paper

Demonstration of polarization behavior of TlBr x-ray imager with silver electrodes

Katsuyuk Takagi, Kohei Toyoda, Hiroki Kase, Toshiyuki Takagi, Kento Tabata, Tsuyoshi Terao, Hisashi Morii, Akifumi Koike, Toru Aoki, Mitsuhiro Nogami, Keitaro Hitomi

Proceedings Volume 11838, 118381E (2021) https://doi.org/10.1117/12.2596374

KEYWORDS: Sensors, Electrodes, Imaging systems, Polarization, Silver, Readout integrated circuits, X-rays, Switching, X-ray imaging, Thallium

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Proceedings Article | 1 September 2021 Presentation + Paper

Simplification of imaging system for estimating changes in image contrast due to different weighting of x-ray energy

Takumi Hotta, Katsuyuki Takagi, Takeru Goto, Akifumi Koike, Yukino Imura, Toru Aoki

Proceedings Volume 11838, 1183813 (2021) https://doi.org/10.1117/12.2596422

KEYWORDS: X-rays, X-ray imaging, Sensors, Imaging systems, X-ray detectors, Photons, Image transmission, Image analysis, Image processing, Visualization

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Proceedings Article | 5 March 2021 Poster + Presentation + Paper

Photon counting x-ray imager with four-sides buttable structure

Toshiyuki Takagi, Katsuyuki Takagi, Tsuyoshi Terao, Hisashi Morii, Takaharu Okunoyama, Hiroki Kase, Akifumi Koike, Toru Aoki

Proceedings Volume 11693, 1169313 (2021) https://doi.org/10.1117/12.2578283

KEYWORDS: X-ray imaging, Photon counting, Imaging systems, Readout integrated circuits, Sensors, Silicon, Semiconductors, Cadmium

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Proceedings Article | 20 August 2020 Poster

Fabrication of pn junction type CdTe diode x-ray detector by backside laser doping

Junichi Nishizawa, Volodymyr Gnatyuk, Katsuyuki Takagi, Akifumi Koike, Toru Aoki

Proceedings Volume 11494, 114941C (2020) https://doi.org/10.1117/12.2568964

KEYWORDS: Doping, Diodes, X-ray detectors, Semiconductor lasers, Laser applications, Pulsed laser operation, Laser irradiation, Laser development, Diffusion, Neodymium

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Proceedings Article | 20 August 2020 Presentation

Long time operation in TlBr X-ray imager using bipolar-input ROIC

Katsuyuki Takagi, Toru Aoki, Keitaro Hitomi, Tsuyoshi Terao, Hiroki Kase, Akifumi Koike

Proceedings Volume 11494, 114940Y (2020) https://doi.org/10.1117/12.2570543

KEYWORDS: Readout integrated circuits, X-ray imaging, Silver, Electrodes, Imaging systems, Sensors, Thallium, Switching, Photon counting, Amplifiers

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Proceedings Article | 6 February 2020 Paper

The high resolution scintillator type x-ray imaging detector with Si pixel collimator

Kento Tabata, Ryota Ohtake, Akihumi Koike, Toru Aoki

Proceedings Volume 11369, 113690S (2020) https://doi.org/10.1117/12.2549936

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Proceedings Article | 9 September 2019 Presentation

TlBr photon-counting imaging device (Conference Presentation)

Toru Aoki, Katsuyuki Takagi, Akifumi Koike, Keitaro Hitomi

Proceedings Volume 11114, 111140Q (2019) https://doi.org/10.1117/12.2529746

KEYWORDS: Photonic devices, Imaging devices, Electrodes, Sensors, X-rays, Gamma radiation, Photon counting, Semiconducting wafers, Thallium, Silver

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Proceedings Article | 9 September 2019 Presentation + Paper

Charge counting readout LSI for x-ray imaging and its applications

Katsuyuki Takagi, Toshiyuki Takagi, Tsuyoshi Terao, Hisashi Morii, Akifumi Koike, Toru Aoki

Proceedings Volume 11114, 111140G (2019) https://doi.org/10.1117/12.2529747

KEYWORDS: X-ray imaging, Signal processing, Sensors, X-rays, Digital signal processing, Spectroscopy, X-ray detectors

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Proceedings Article | 13 September 2018 Paper

Contrast mediums discrimination by spectral photon-counting CT imaging

K. Kimura, A. Koike, T. Aoki

Proceedings Volume 10762, 1076213 (2018) https://doi.org/10.1117/12.2320978

KEYWORDS: X-rays, X-ray computed tomography, X-ray imaging, Radiography, Photons, Sensors, Iodine, Absorption, Magnetic resonance imaging, Tissues

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Proceedings Article | 14 May 2018 Paper

Readout QDC for CdTe x-ray imager using direct charge treatment

Katsuyuki Takagi, Toshiyuki Takagi, Tsuyoshi Terao, Akifumi Koike, Toru Aoki

Proceedings Volume 10656, 106561W (2018) https://doi.org/10.1117/12.2316419

KEYWORDS: Photon counting, Sensors, X-ray imaging, X-rays, X-ray detectors, Semiconductors, Time correlated photon counting, Quantization, Imaging systems, Spectroscopy

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Proceedings Article | 14 May 2018 Presentation

Low dose x-ray imaging by photon counting detector (Conference Presentation)

Toru Aoki, Kosuke Kimura, Hisashi Morii, Toshiyuki Takagi, Katsuyuki Takagi, Tsuyoshi Terao, Takaharu Okunoyama, Akifumi Koike

Proceedings Volume 10656, 106560Y (2018) https://doi.org/10.1117/12.2316418

KEYWORDS: Photon counting, X-ray imaging, Sensors, X-ray computed tomography, Imaging systems, Signal attenuation, Hard x-rays, Medical imaging, Signal processing, X-ray sources

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Proceedings Article | 16 June 2017 Presentation

Nano scale doping in CdTe for radiation detector (Conference Presentation)

Toru Aoki, Kateryna Zelenska, Volodymyr Gnatyuk, Akifumi Koike

Proceedings Volume 10248, 102480T (2017) https://doi.org/10.1117/12.2267528

KEYWORDS: Diodes, Laser processing, Semiconductor physics, Doping, Sensors, Crystals, Laser crystals, Semiconductor lasers, Semiconductors, Laser irradiation

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Proceedings Article | 2 June 2017 Paper

Direct charge handling method for dead-time-less photon counting

Katsuyuki Takagi, Akifumi Koike, Toru Aoki

Proceedings Volume 10209, 102091D (2017) https://doi.org/10.1117/12.2272805

KEYWORDS: X-ray imaging, Quantization, Time correlated photon counting, Photography, Imaging systems, Sensors, X-rays, Photon counting, Semiconductors, X-ray detectors

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Proceedings Article | 2 November 2016 Presentation

CdTe imaging device driven by current integration mode (Conference Presentation)

Toru Aoki, Akifumi Koike, Takaharu Okunoyama, Hisashi Morii, Katsuyuki Takagi, Junichi Nishizawa

Proceedings Volume 9968, 996809 (2016) https://doi.org/10.1117/12.2240381

KEYWORDS: Imaging devices, Sensors, Algorithm development, Data corrections, Detection and tracking algorithms, Field programmable gate arrays, Hard x-rays, Gamma radiation, Physics, Current controlled current source

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Proceedings Article | 30 September 2016 Paper

CsI:Tl scintillator separated by Si grid partition wall

Kento Tabata, Junichi Nishizawa, Akihumi Koike, Toru Aoki

Proceedings Volume 9968, 99681H (2016) https://doi.org/10.1117/12.2238424

KEYWORDS: Scintillators, Silicon, X-rays, Luminescence, Wafer-level optics, Image sensors, Sensors, Diffusion, Photodiodes, Microelectromechanical systems

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Proceedings Article | 28 September 2011 Paper

Carrier transportation properties in M-p-n and Schottky CdTe diode detector

Manato Kimura, Akifumi Koike, Takaharu Okunoayama, Hisashi Morii, Shailendra Singh, Toshitaka Yamakawa, Hidenori Mimura, Toru Aoki

Proceedings Volume 8142, 81421D (2011) https://doi.org/10.1117/12.896969

KEYWORDS: Sensors, Diodes, Polarization, Signal processing, Europium, Imaging systems, Signal detection, Absorption, Time metrology, Photon counting

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Proceedings Article | 23 September 2011 Paper

Evaluation of characteristics of CdTe detector by laser pulses

Yuto Suzuki, Tetsu Ito, Akifumi Koike, Hisashi Morii, Aki Miyake, Yoichiro Neo, Hidenori Mimura, Toru Aoki

Proceedings Volume 8142, 814209 (2011) https://doi.org/10.1117/12.896585

KEYWORDS: Sensors, Pulsed laser operation, Signal detection, Absorption, Solids, Laser energy, Polarization, Semiconductor lasers, Oscilloscopes, Time metrology

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Proceedings Article | 27 August 2010 Paper

Improvement of analysis precision upon the atomic number and electron density measurement by the dual x-ray CT

Yukino Imura, Hisashi Morii, Akifumi Koike, Takaharu Okunoyama, Yoichiro Neo, Hidenori Mimura, Toru Aoki

Proceedings Volume 7805, 78051M (2010) https://doi.org/10.1117/12.862639

KEYWORDS: Signal attenuation, Sensors, X-rays, X-ray computed tomography, X-ray detectors, Aluminum, Gamma radiation, X-ray imaging, Scattering, Absorption

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Proceedings Article | 28 September 2009 Paper

High-speed photon counting processing for CdTe detector

B. Shinomiya, A. Koike, H. Morii, T. Okunoyama, Y. Neo, H. Mimura, T. Aoki

Proceedings Volume 7449, 74490J (2009) https://doi.org/10.1117/12.826007

KEYWORDS: X-rays, Signal processing, Sensors, Photon counting, X-ray detectors, Aluminum, X-ray imaging, Oscilloscopes, Signal attenuation, Semiconductors

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Proceedings Article | 4 September 2008 Paper

CdTe x-ray image sensor driven by field emitter array

Toru Aoki, Takuya Sakata, Yuichiro Hanawa, Masashi Nakagawa, Hisashi Morii, Akifumi Koike, Yoichiro Neo, Hidenori Mimura

Proceedings Volume 7079, 707912 (2008) https://doi.org/10.1117/12.795654

KEYWORDS: X-rays, Finite element methods, Image sensors, X-ray imaging, Electrodes, Diodes, Copper, Electron beams, Reactive ion etching, Spatial resolution

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Proceedings Article | 4 September 2008 Paper

Photon counting x-ray CT with 3D holograms by CdTe line sensor

A. Koike, M. Yomori, H. Morii, Y. Neo, T. Aoki, H. Mimura

Proceedings Volume 7079, 70790F (2008) https://doi.org/10.1117/12.796908

KEYWORDS: X-rays, X-ray computed tomography, Holograms, 3D displays, Holography, 3D image reconstruction, X-ray imaging, 3D image processing, Displays, Sensors

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Proceedings Article | 22 April 2008 Paper

Full-color image reconstruction by holography for 3D x-ray CT

Akifumi Koike, Hisashi Morii, Mitsuhiro Yomori, Yoichiro Neo, Toru Aoki, Hidenori Mimura

Proceedings Volume 7008, 70081H (2008) https://doi.org/10.1117/12.797349

KEYWORDS: Holograms, X-rays, 3D image reconstruction, LCDs, Holography, 3D image processing, 3D displays, X-ray detectors, X-ray computed tomography, X-ray imaging

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Showing 5 of 23 publications

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