Real time observation of mouse fetal skeleton using a high resolution X-ray synchrotron

장동우,김보라,신재훈,윤영민,제정호,Yeu kuang Hwu,윤정희,성제경 대한수의학회 2011 Journal of Veterinary Science Vol.12 No.2

The X-ray synchrotron is quite different from conventional radiation sources. This technique may expand the capabilities of conventional radiology and be applied in novel manners for special cases. To evaluate the usefulness of X-ray synchrotron radiation systems for real time observations, mouse fetal skeleton development was monitored with a high resolution X-ray synchrotron. A non-monochromatized X-ray synchrotron (white beam, 5C1 beamline) was employed to observe the skeleton of mice under anesthesia at embryonic day (E)12, E14, E15, and E18. At the same time, conventional radiography and mammography were used to compare with X-ray synchrotron. After synchrotron radiation, each mouse was sacrificed and stained with Alizarin red S and Alcian blue to observe bony structures. Synchrotron radiation enabled us to view the mouse fetal skeleton beginning at gestation. Synchrotron radiation systems facilitate real time observations of the fetal skeleton with greater accuracy and magnification compared to mammography and conventional radiography. Our results show that X-ray synchrotron systems can be used to observe the fine structures of internal organs at high magnification.

Synchrotron infrared spectroscopy and its applications

채복남 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Most synchrotron facilities offer a port dedicated to infrared (IR) spectroscopy and infrared-microspectroscopy. The main advantage of synchrotron-based infrared spectroscopy is the brightness of synch-rotron radiation source. The synchrotron radiation source provides brightness 2-3 orders of magnitude higher than a thermal infrared source. Thus, synchrotron based infrared spectroscopy has allowed high spatial resolution and high spectral resolution, especially for low throughput technologies and far-infrared spectroscopy. Infrared beamlines are now facing an increasing demand of beamtime from various disciplines: Polymer Science, Biology, biomedical applications, Earth Science, Environmental science, Chemistry, Cultural Heritage, Archaeology and soft matter. Synchrotron-based infrared spectroscopy and its applications will be presented. In addition, the current status of infrared beamline of PAL will be discussed.

Strip-line injection kicker for PAL-EUV booster synchrotron

Ko Jun Ho,Kim Min Woo,Lee Sojeong,한장희,홍주호 한국물리학회 2024 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.84 No.3

There has been a demand for compact-size extreme ultraviolet (EUV) storage ring synchrotron facilities with sizes within tens of meters for use in the semiconductor industry. To meet this demand, Pohang Accelerator Laboratory developed the PAL-EUV facility in an area of 15 m × 15 m or less. From the constraint, PAL-EUV has a photocathode RF gun, a 3 m S-band linear accelerator, a 22.2 m circumference booster synchrotron, and a 36 m circumference storage ring synchrotron. We use the strip-line injection kicker for the booster synchrotron injection. The booster synchrotron strip-line injection kicker has a 0.24 m efective length, 7.3 kV strip-line kick voltage, and about 10 ns pulse duration. In this paper, we introduce the overall parameters of the strip-line injection kicker, the signal simulation and wake-feld simulation, the result of the high voltage conditioning test under vacuum, and the operation result after the installation in the PAL-EUV tunnel.

Lattice Design and Electron Cloud Instability in a High-Intensity Proton Synchrotron

김은산 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.4

The proton accelerators for the neutron spallation source and nuclear experiments usually consist of a high-intensity linac and a synchrotron. An important issue in such a high intensity accelerator is to keep particle losses by beam injection from the linac and beam instabilities in the synchrotron down to an acceptable level. We show the analysis results of optics design and beam dynamics for a 4-GeV high-intensity proton synchrotron. A lattice with a high transition gamma is chosen to avoid the beam loss at the transition crossing, and the stabilities on the lattice are also investigated by examining the effects of machine errors. We investigate the characteristics of the electron cloud instability, which may limit the beam performance in the high-intensity proton synchrotron. We present the analysis on the beam dynamics in the proton synchrotron with a low injection energy of around 100 MeV. From these results, we present the results on the choice of injection beam energy and on the available beam power in terms of the space charge effects and the electron cloud instability.

가속기 노광을 이용한 PMMA 현상에 관한 연구

김진태 ( Jin Tae Kim ),김병철 ( Byeong Cheol Kim ),정명영 ( Myung Yung Jeong ) 한국공업화학회 2003 공업화학 Vol.14 No.2

LIGA 공정에서 널리 사용되는 PMMA는 Synchrotron에서 방사되는 X-ray의 스펙트럼과 조사량에 따라 동일한 현상액에서 상이한 현상율을 나타내며, 이는 미세구조물의 공차와 표면상태를 결정짓는 중요 변수로 작용하고 있다. 따라서 PMMA에 조사되는 X-ray의 스펙트럼과 조사량의 관계 및 X-ray 조사량에 따른 PMMA 현상율의 변화 등에 대한 정확한 이해가 필요하다. 본 연구에서는 Synchrotron에서 방사되는 X-ray의 스펙트럼 분포 변화와 노광 시간에 따라 상이한 표면조사량과 바닥조사량을 갖는 PMMA 시료의 현상율을 GG 현상액을 이용하여 측정하였다. 표면 조사량에 따른 PMMA의 현상율은 일정 조사량에서 수렴되는 지수함수로 표현이 가능하였고, PMMA의 현상을 위해서는 노광되는 X-ray 스펙트럼 분포와 상관없이 2kJ/cm_3 이상의 표면조사량이 필요하며, 수백 미크론 크기의 미세구조물 성형을 위해서는 5~6kJ/cm^3의 바닥조사량이 최적임을 확인하였다. Development rates of polymethylmethacrylate(PMMA) are significantly influenced by parameters such as x-ray spectrum radiated from synchrotron and irradiated dose. Tolerance and surface quality of the micro-size structures of the irradiated PMMA are affected by the parameters of LIGA process. In this study, x-ray spectrum radiated from the synchrotron source was modified by Al film, and then the doses were deposited on the top and bottom of the PMMA sample sheet prior to measurement. Experimental development rates by GG developer for the treated PMMA sample showed a power-law relationship with doses. A proper micro-size structure fabrication required a dose between 2 kJ/cm^3 and 6 kJ/cm^3.

Design of the KHIMA Synchrotron

임희중,안동현,한가람,박차원,김근범 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.8

The Korea Heavy Ion Medical Accelerator project (KHIMA) has been proposed as an ion-beam synchrotron facility for cancer therapy. The facility will be installed at Gijang, Busan with completion in 2017. The proposed maximum energy of the ions is 430 MeV/u (for carbon) to cover various tumor depths up to 30 cm. For the synchrotron design, we optimized the lattice configuration to fit the therapy. We discuss here the status of the synchrotron’s design.

Fluorapatite diagenetic differences between Cretaceous skeletal fossils of Mongolia and Korea

Kim, Taehyun,Lee, Yongjae,Lee, Yuong-Nam Elsevier 2018 Palaeogeography, palaeoclimatology, palaeoecology Vol.490 No.-

<P><B>Abstract</B></P> <P>The skeletal tissue of modern bones is mostly composed of hydroxyapatite, which contains calcium and phosphate. During diagenesis, calcium, phosphorus and minerals of the hydroxyl group can be exchanged with other elements to form carbonate-fluorapatite. It is well-established that paleoenvironmental evolution and geological events have played a significant role in the compositional changes of fossilized bones. For example, skeletal fossils from the Hasandong Formation (Aptian- early Albian) of the Gyeongsang Basin in Korea are characterized by black and dark colors, whereas dinosaur bones from the Nemegt Formation (early Maastrichtian) of the Nemegt and Altan Uul ranges in Mongolia are light brown and white. This study investigated the mineralogical and geochemical causes for the differences in coloration between these two groups of fossilized bones. Multiple synchrotron-based techniques were utilized, including synchrotron–XRF, –XRD, –X-ray micro-computed tomography (μ-CT), micro-XRF and SEM-EDX data to analyze the elemental composition and mineral phases in dark Korean fossilized bones, which are characterized by the presence of iron, aluminum, magnesium and other trace elements. Chamosite was identified as a secondary mineral at 5% by weight of the total fossil mass, which is primarily composed of carbonate-fluorapatite. However, skeletal fossils from Mongolia are characterized by secondary minerals, such as barite, goethite and calcite, which accumulate in pore spaces. Since different secondary minerals result from different alteration procedures, the presence of chamosite in the Korean fossils suggests alteration by spatial replacement, and the presence of barite in the Mongolian fossils suggests alteration by accumulation. The investigation of these two skeletal groups, analyzed using a suite of synchrotron-based multidisciplinary techniques, revealed contrasting mineralogical and geochemical details and helps to determine the origin of fossil colorization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two distinct colorizations in fossilized bones show different degrees of alteration in the original bone material. </LI> <LI> Secondary mineral phases have indicated spatial replacement and precipitation processes during respective alteration. </LI> <LI> Synchrotron-based X-ray techniques are shown to be useful in revealing mineralogical and chemical information of fossils. </LI> </UL> </P>

Current Status and Future Directions of Synchrotron-Based Research on Used Fuel and Radioactive Waste

윤인호,이상호,신영호,김성만,이정묵,김태형,임상호,김종윤 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Disposal of used Nuclear Fuels and Radioactive wastes is becoming a critical concern in Korea where the decommissioning of nuclear power plants is just around the corner. Improvement in remediation and treatment technologies is now urgently required to reduce the amount of wastes by understanding the complex chemical system composed of various elements. Used fuels are not actually a waste. They contain plenty of artificial elements which can be useful in some specialized applications for the future. Synchrotron techniques such as X-ray absorption near-edge structure (XANES), extended X-ray absorption fine structure (EXAFS) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray scattering (XRS), etc. are expected to provide a powerful tool to search for new strategic materials as well as to solve the critical issues in decommissioning and remediation, and safety of the final disposal of the radioactive wastes.

Optimization of the Multi-Turn Injection Efficiency for a Medical Synchrotron

J. Kim,M. Yoon,H. Yim 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.6

We present a method for optimizing the multi-turn injection efficiency for a medical synchrotron. We show that for a given injection energy, the injection efficiency can be greatly enhanced by choosing transverse tunes appropriately and by optimizing the injection bump and the number of turns required for beam injection. We verify our study by applying the method to the Korea Heavy Ion Medical Accelerator (KHIMA) synchrotron which is currently being built at the campus of Dongnam Institute of Radiological and Medical Sciences (DIRAMS) in Busan, Korea. First the frequency map analysis was performed with the help of the ELEGANT and the ACCSIM codes. The tunes that yielded good injection efficiency were then selected. With these tunes, the injection bump and the number of turns required for injection were then optimized by tracking a number of particles for up to one thousand turns after injection, beyond which no further beam loss occurred. Results for the optimization of the injection efficiency for proton ions are presented.

Structural Changes in Isothermal Crystallization Processes of Synthetic Polymers Studied by Time-Resolved Measurements of Synchrotron-Sourced X-Ray Scatterings and Vibrational Spectra

Tashiro, Kohji,Hama, Hisakatsu The Polymer Society of Korea 2004 Macromolecular Research Vol.12 No.1

The structural changes occurring in the isothermal crystallization processes of polyethylene (PE), poly-oxymethylene (POM), and vinylidene fluoridetrifluoroethylene (VDFTrFE) copolymer have been reviewed on the basis of our recent experimental data collected by the time-resolved measurements of synchrotron-sourced wide-angle (WAXS) and small-angle X-ray scatterings (SAXS) and infrared spectra. The temperature jump from the melt to a crystallization temperature could be measured at a cooling rate of 600-1,000 $^{\circ}C$/min, during which we collected the WAXS, SAXS, and infrared spectral data successfully at time intervals of ca. 10 sec. In the case of PE, the infrared spectral data clarified the generation of chain segments of partially disordered trans conformations immediately after the jump. These segments then became transformed into more-regular all-trans-zigzag forms, followed by the formation of an orthorhombic crystal lattice. At this stage, the generation of a stacked lamella structure having an 800-${\AA}$-long period was detected in the SAXS data. This structure was found to transfer successively to a more densely packed lamella structure having a 400-${\AA}$-long period as a result of the secondary crystallization of the amorphous region in-between the original lamellae. As for POM, the formation process of a stacked lamella structure was essentially the same as that mentioned above for PE, as evidenced from the analysis of SAXS and WAXS data. The observation of morphology-sensitive infrared bands revealed the evolution of fully extended helical chains after the generation of lamella having folded chain structures. We speculate that these extended chains exist as taut tie chains passing continuously through the neighboring lamellae. In the isothermal crystallization of VDFTrFE copolymer from the melt, a paraelectric high-temperature phase was detected at first and then it transferred into the ferroelectric low-temperature phase at a later stage. By analyzing the reflection profile of the WAXS data, the structural ordering in the high-temperature phase and the ferroelectric phase transition to the low-temperature phase of the multi-domain structure were traced successfully.