A5069440104- Advanced Radiotherapy Techniques
- Advanced X-ray and CT Imaging
- Radiation Dose and Imaging
- Radiation Shielding Materials Analysis
- Digital Radiography and Breast Imaging
- Medical Imaging Techniques and Applications
- CCD and CMOS Imaging Sensors
- Astro and Planetary Science
- Radiation Therapy and Dosimetry
- Thin-Film Transistor Technologies
- Spacecraft Dynamics and Control
- X-ray Spectroscopy and Fluorescence Analysis
- High voltage insulation and dielectric phenomena
- Graphite, nuclear technology, radiation studies
- Planetary Science and Exploration
- Radiation Effects and Dosimetry
- Space Science and Extraterrestrial Life
- Infrared Target Detection Methodologies
- Advanced Memory and Neural Computing
- Spacecraft and Cryogenic Technologies
- Nuclear Physics and Applications
- Electron and X-Ray Spectroscopy Techniques
- Radiation Detection and Scintillator Technologies
- Advanced Sensor and Energy Harvesting Materials
- Nuclear and radioactivity studies
Institute of Space and Astronautical Science
2016-2021
Japan Aerospace Exploration Agency
2014-2020
Rikkyo University
2020
Fujita Health University
2009-2019
Olympus (Japan)
2013-2018
Proton Therapy Centre
2015
Kashiwa Municipal Hospital
2000-2014
Seirei Hamamatsu General Hospital
2012
Ridgeview Medical Center
2011
University of Minnesota
2011
Collecting a sample of asteroid Ryugu The Hayabusa2 spacecraft recently traveled to the nearby carbonaceous collect samples and return them Earth for laboratory analysis. Morota et al. describe Hayabusa2's first collection, taken during brief touchdown on Ryugu's surface. Close-up images video sampling process allowed authors investigate surface colors morphology small scale. Relating these craters stratigraphy constrains evolution Ryugu. conclude that experienced prior period strong solar...
Dual-energy projection radiography was applied to breast examinations. To perform the dual-energy subtraction with use of a digital unit, high- and low-energy projections were made at an appropriate time interval under differing x-ray exposure conditions. appears offer clear, detailed images may be useful supplement standard mammography.
A 16Mpixel 3D stacked CMOS image sensor with pixel level interconnections using 4,008,960 micro bumps at a 7.6μm pitch, which set no layout restriction and causes harm to characteristics, was developed achieve both global-shutter mode −180dB PLS 2Mpixel 10000fps high speed capturing mode.
Conventional CMOS image sensors widely used in products currently on the market are mainly equipped with a rolling exposure function. This causes so-called "Jell-o effect" distortion when capturing moving target. global-shutter function one of solutions to avoid this distortion. An in-pixel storage node is required create sensor. A floating diffusion and an additional capacitor can be as [1,2]. The light sensitivity specified by parasitic (PLS), which ratio photodiode. PLS should small...
We have developed a 3-D-stacked 16-Mpixel, 3.8- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> pitch, and global shutter (GS) CMOS image sensor with 2-Mpixel 10 000-frames/s high-speed image-capturing mode, four million reliable microbump interconnections. This consists of photodiode (PD) substrate an in-pixel storage node substrate. The PDs in the unit pixel...
The purpose of this study was to evaluate the triple channel correction acquisition (TCCA) method for radiochromic film dosimetry performed with a flatbed scanner. had two parts: fundamental and clinical examination. In examination, we evaluated accuracy calibration curves Gafchromic EBT2 (EBT2). films were calibrated using field-by-field 13 dose steps. Seven obtained by TCCA compared those produced single (SCA) method. For relative distributions SCA four cases intensity-modulated radiation...
The solar power sail can generate sufficient electric to drive the high specific ion engine in outer planetary region by thin-film cells attached entire surface of spin-type sail. This paper proposes direct exploration using sail-craft. target is an unexplored D/P-type Jovian Trojan asteroid. A lander separated from sail-craft collect and underground samples asteroid perform in-situ analysis. delivers for sample return Earth as optional goal. Scientific observations during interplanetary...
The backscatter factor is necessary for evaluating the skin dose of patients irradiated by diagnostic x-rays. In this study, factors x-rays various irradiation conditions were calculated means Monte Carlo method. X-rays, which had same HVL but different tube potentials, did not always coincide with each other. From result, it was evidenced that obtained from BSF data table a parameter uncertain. To avoid such uncertainties, new convolution method to obtain using an x-ray spectrum and...
This paper reports on the manufacturing and evaluation of a solar power sail membrane prototype for OKEANOS project. The in-house was built by Institute Space Astronautical Science, Japan Aerospace Exploration Agency. Mechanical electrical tests were conducted. membrane, thin-film cells, reflectivity control devices good condition after handling. improvements in process design found. fundamentally established. After prototype, improvement plans tried. We have prospect flight model continue...
The solar power sail is an original Japanese concept in which electrical generated by thin-film cells on the membrane. It can generate sufficient electric to drive high-specific ion engines outer planetary region. We propose a landing or sample return mission explore Jupiter Trojan asteroid directly using sail. After rendezvousing with asteroid, lander separates from sail-craft collect surface and underground samples, perform in-situ analysis Plan-A/B. In addition, delivers samples Plan-B....
Photon mass energy transfer coefficient is an essential factor when converting photon fluence into kinetic released per unit (kerma). Although attenuation and absorption coefficients can be looked up in databases, the values are still controversial. In this paper, for elements Z=1–92 were calculated based on cross-sectional data each interaction type. Mass 48 compounds and/or mixtures of dosimetric interest from using Bragg’s additivity rule. We additionally developed software that search...
We demonstrated multiband imaging with a multi-storied photodiode CMOS image sensor (CIS), which comprises two individually functioning layered devices that achieve optimized images in different substrates bonded by 3D technology. The is able to capture wide variety of images, not limited conventional visible RGB (Red Green Blue) taken Bayer filter or invisible infrared (IR) at the same time without any color degradation even an extra IR light source. Its range sensitivity enables us select...
It is important to precisely evaluate patient dose from a diagnostic X-ray in order investigate medical exposure reduction. As method of evaluating surface dose, computation with existing data based on air generally used. With this method, backscatter factors and absorbed conversion are given by the parameter effective energy or half value layer, making procedure complicated. We developed program software (Surface Dose Evaluation Code, SDEC) that computes automatically, using factor...
A presumption calculating formula of the X-ray spectrum generated from a molybdenum target tube is presented. The calculation procedure to add an amount characteristic photons that corresponds ratio and bremsstrahlung obtained using semiempirical calculation. was calculated by corrected Tucker's formula. content for self-absorption length in originated difference incident angle electron mass stopping power data. measured separated into component photon component, obtained. regression derived...
The effective energy has been generally used as a method of handily expressing an X-ray quality by one numerical value. is concept derived from “Half Value Layer (HVL)” that the parameter beam based on attenuation primary material. When expressed using HVL and / or energy, it necessary to describe tube potential, rectification method, homogeneity coefficient, etc. in parallel. However, recently feelings are should be handled like absolute value physical characteristics X-rays. In this paper,...
We have developed a 3D stacked 16Mpixel global-shutter CMOS image sensor with pixel level interconnections using four million micro bumps. The photodiodes in the unit circuit on top substrate share one micro-bump interconnection 7.6μm pitch. Each signal of is transferred to corresponding storage node bottom via achieve function. ratio parasitic light sensitivity an in-pixel and photodiode –180dB 3.8μm pixel. In addition, we discuss further improvement reduce noise figure sensors.
We have developed a 3D stacked 16M-pixel, 3.8-μm pixel pitch, global-shutter CMOS image sensor with level interconnections using four million micro bumps. The photodiodes in the unit circuit on top substrate share one micro-bump interconnection at 7.6-μm pitch. Each signal of is transferred to corresponding storage node bottom via bump. This architecture gives not only 16M-pixel function but also 2M-pixel 10K-fps high-speed capturing mode burst eight images. In this paper, we report...
医用放射線による患者被曝線量を正確に評価することは,医療被曝低減を探求していくうえで最も基本となるものである.患者被曝線量を表現するには,入射皮膚表面の吸収線量とともに,体内吸収線量分布を評価できることが望ましい.入射皮膚表面線量の評価法は,本学会計測分科会によって詳しく解説されており,比較的容易に表面吸収線量を求めることができる.以前にわれわれは,その計算上の一因子である後方散乱係数の算出法について報告した.一方,診断X線照射時の体内線量分布を表現することは,人体内の組織構造が複雑であるため非常に困難である.体内線量分布の評価には,人体ファントムを用いて個々に測定する方法や,数学ファントムを用いたシミュレーションにより評価する方法があるが,一般に普及するまでには至っていない.本稿では,体内線量分布評価の第一段階として,均質組織ファントム(ICRUスラブ)中におけるX線束中心軸上の深部線量百分率を取り上げる.診断X線の深部線量百分率データに関してはこれまであまり報告されておらず,文献に公表されているデータもX線治療装置や単相金波整流方式の診断X線装置を用いて測定されたものが多く,...
To obtain patient entrance surface dose in X-ray photography, a calculation method based on measured exposure or air kerma radiated from tube is generally used. Two factors are necessary for this calculation: (1) exposure/air to absorb conversion factor and (2) back-scatter (BSF) quality field size. These BSFs commonly obtained by interpolation existent data which were given water phantom whose flat. Since patient's photograph not flat, some error may occur when BSF used calculation. In...
When computing the amount of leakage from a diagnostic X-ray room, transmission data beams through shielding material, which are used in computation, must agree with conditions use equipment. Even if tube potential is same, energy spectrum generated X-rays depends on such as high voltage rectification and total filtration, too, subject to change. In this paper, we propose new method calculation, uses mono-energetic photon computed by means Monte Carlo simulation, for obtaining effective dose...