Large size growth of terbium doped BaCl2/NaCl/KCl eutectic for radiation imaging

Author(s):  
Yui Takizawa ◽  
Kei Kamada ◽  
Kyoung Jin Kim ◽  
Masao Yoshino ◽  
Akihiro Yamaji ◽  
...  

Abstract In this study, a large-size eutectic scintillator of Tb-doped BaCl2/NaCl/KCl was grown using the Czochralski (Cz) and halide vertical Bridgman methods (H-VB). The suitability of these two growth methods for growing the eutectic was compared. Finally, 1 diameter eutectic bulks were obtained using the H-VB method. The Tb3+-derived strongest intensity peak at approximately 550 nm was observed by X-ray irradiation. An approximately 3 × 3 mm transparent eutectic plate was cut and polished from the grown eutectic bulk. An α-ray imaging test was performed using the eutectic plate, a fiber optic plate, and an electron-multiplying CCD camera. The resolution performance for radiation-imaging applications was evaluated.

2006 ◽  
Vol 2 (S237) ◽  
pp. 421-421
Author(s):  
K. Hamaguchi ◽  
R. Petre ◽  

AbstractThe Carina Nebula possesses the brightest soft diffuse X-ray emission among the Galactic giant HII regions, but the origin has not been known yet. The XIS1 back-illuminated CCD camera onboard the Suzaku X-ray observatory has the best spectral resolution for extended soft sources so far, and is therefore capable of measuring these key emission lines in the soft diffuse plasma. Suzaku observed the Carina nebula on 2005 Aug. 29. The XIS1 spectra of the Carina nebula clearly showed spatial variations in emission line strengths. In the south, the spectrum showed strong L-shell lines of iron ions and K-shell lines of silicon ions, while in the north these lines were much weaker. Fitting the spectra with an absorbed thin-thermal plasma model with kT ~ 0.2, 0.6 keV and NH ~ −2 × 1021 cm−2 showed that the silicon and iron abundance is about 2–3 times higher in the south than in the north. Because of its large size (~40 pc), the diffuse emission in the Carina nebula might have been produced by an old supernova, or a super shell produced by multiple supernovae.


2018 ◽  
Vol 174 ◽  
pp. 02003
Author(s):  
Takeshi Fujiwara ◽  
Yuki Mitsuya ◽  
Hiroyuki Takahashi ◽  
Hiroyuki Toyokawa

A large size x-ray imaging gaseous detector, which has 280 × 280 mm2 effective area has been successfully developed and x-ray imaging has been demonstrated. The imaging system consists of a chamber filled with Ne/CF4 scintillating gas mixture, inside of which Glass GEM (G-GEM) is mounted for gas multiplication. In this system electrons are generated by the reaction between x-rays and the gas, and visible photons by excited Ne/CF4 gas molecules during the gas electron multiplication process in the G-GEM holes. These photons are simply detected with CCD-camera and a radiograph is formed. Here, we report on the properties of large size scintillation G-GEM and the results of using it as a digital x-ray imager with a large sensitive area.


Author(s):  
James F. Mancuso ◽  
William B. Maxwell ◽  
Russell E. Camp ◽  
Mark H. Ellisman

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.


Proceedings ◽  
2020 ◽  
Vol 62 (1) ◽  
pp. 4
Author(s):  
Hadj Bellagra ◽  
Oksana Nyhmatullina ◽  
Yuri Kogut ◽  
Halyna Myronchuk ◽  
Lyudmyla Piskach

Quaternary semiconductor materials of the Pb4Ga4GeS(Se)12 composition have attracted the attention of researchers due to their possible use as active elements of optoelectronics and nonlinear optics. The Pb4Ga4GeS(Se)12 phases belong to the solid solution ranges of the Pb3Ga2GeS(Se)8 compounds which form in the quasi-ternary systems PbS(Se)−Ga2S(Se)3−GeS(Se)2 at the cross of the PbGa2S(Se)4−Pb2GeS(Se)4 and PbS(Se)−PbGa2GeS(Se)6 sections. The quaternary sulfide melts congruently at 943 K. The crystallization of the Pb4Ga4GeSe12 phase is associated with the ternary peritectic process Lp + PbSe ↔ PbGa2S4 + Pb3Ga2GeSe8 at 868 K. For the single crystal studies, Pb4Ga4GeS(Se)12 were pre-synthesized by co-melting high-purity elements. The X-ray diffraction results confirm that these compounds possess non-centrosymmetric crystal structure (tetragonal symmetry, space group P–421c). The crystals were grown by the vertical Bridgman method in a two-zone furnace. The starting composition was stoichiometric for Pb4Ga4GeS12, and the solution-melt method was used for the selenide Pb4Ga4GeSe12. The obtained value of the bandgap energy for the Pb4Ga4GeS12 and Pb4Ga4GeSe12 crystals is 1.86 and 2.28 eV, respectively. Experimental measurements of the spectral distribution of photoconductivity for the Pb4Ga4GeS12 and Pb4Ga4GeSe12 crystals exhibit the presence of two spectral maxima. The first lies in the region of 570 (2.17 eV) and 680 nm (1.82 eV), respectively, and matches the optical bandgap estimates well. The locations of the admixture maxima at about 1030 (1.20 eV) and 1340 nm (0.92 eV), respectively, agree satisfactorily with the calculated energy positions of the defects vs. and VSe.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 80
Author(s):  
Robert Paszkowski ◽  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Dariusz Szeliga ◽  
Jan Sieniawski

The roots of cored single-crystalline turbine blades made of a nickel-based CMSX-4 superalloy were studied. The casts were solidified by the vertical Bridgman method in an industrial ALD furnace using the spiral selector and selector continuer situated asymmetrically in the blade root transverse section. Scanning electron microscopy, the Laue diffraction and X-ray diffraction topography were used to visualize the dendrite array and the local crystal misorientation of the roots. It has been stated that heterogeneity of the dendrite array and creation of low-angle boundaries (LABs) are mostly related to the lateral dendrite branching and rapid growth of the secondary and tertiary dendrites near the surface of the continuer–root connection. These processes have an unsteady character. Additionally, the influence of the mould walls on the dendrite array heterogeneity was studied. The processes of the lateral growth of the secondary dendrites and competitive longitudinal growth of the tertiary dendrites are discussed and a method of reducing the heterogeneity of the root dendrite array is proposed.


1975 ◽  
Vol 14 (7) ◽  
pp. 1484 ◽  
Author(s):  
Clayton W. Bates ◽  
Stephen D. Sparks
Keyword(s):  

2021 ◽  
Vol 7 (1) ◽  
pp. 14
Author(s):  
Dewi Suriyani Che Halin ◽  
Kamrosni Abdul Razak ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Mohd Izrul Izwan Ramli ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
...  

Ag/TiO2 thin films were prepared using the sol-gel spin coating method. The microstructural growth behaviors of the prepared Ag/TiO2 thin films were elucidated using real-time synchrotron radiation imaging, its structure was determined using grazing incidence X-ray diffraction (GIXRD), its morphology was imaged using the field emission scanning electron microscopy (FESEM), and its surface topography was examined using the atomic force microscope (AFM) in contact mode. The cubical shape was detected and identified as Ag, while the anatase, TiO2 thin film resembled a porous ring-like structure. It was found that each ring that coalesced and formed channels occurred at a low annealing temperature of 280 °C. The energy dispersive X-ray (EDX) result revealed a small amount of Ag presence in the Ag/TiO2 thin films. From the in-situ synchrotron radiation imaging, it was observed that as the annealing time increased, the growth of Ag/TiO2 also increased in terms of area and the number of junctions. The growth rate of Ag/TiO2 at 600 s was 47.26 µm2/s, and after 1200 s it decreased to 11.50 µm2/s and 11.55 µm2/s at 1800 s. Prolonged annealing will further decrease the growth rate to 5.94 µm2/s, 4.12 µm2/s and 4.86 µm2/s at 2400 s, 3000 s and 3600 s, respectively.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lian Wang ◽  
Juncheng Zhou ◽  
Yuhao Chen ◽  
Liu Xiao ◽  
Guojia Huang ◽  
...  

Abstract An intensity modulated fiber-optic carbon monoxide (CO) sensor by integrating in-situ solvothermal-growth Ag/Co-MOF sensing film is fabricated and evaluated. The Michelson interference sensing structure is composed of single-mode fiber (SMF), enlarged taper, thin-core fiber (TCF), and Ag film as the reflector. Ag/Co-MOF was coated on the cladding of the TCF as the sensing material, and the enlarged taper is located between TCF and SMF as the coupler. The structure, morphology, compositions and thermal stability of the Ag/Co-MOF sensing film were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), etc. The sensitivity of the sensor is 0.04515 dB/ppm, and the fitting parameter of the CO concentration is 0.99876. In addition, the sensor has the advantages of good selectivity, good signal and temperature stability, and it has potential application in trace CO detection.


2011 ◽  
Vol 38 (3) ◽  
pp. 1374-1377 ◽  
Author(s):  
David M. Klein ◽  
Francois Therriault-Proulx ◽  
Louis Archambault ◽  
Tina M. Briere ◽  
Luc Beaulieu ◽  
...  

1998 ◽  
Vol 5 (3) ◽  
pp. 642-644 ◽  
Author(s):  
J. Y. Huang ◽  
I. S. Ko

A diagnostic beamline is being constructed in the PLS storage ring for measurement of electron- and photon-beam properties. It consists of two 1:1 imaging systems: a visible-light imaging system and a soft X-ray imaging system. In the visible-light imaging system, the transverse beam size and beam position are measured with various detectors: a CCD camera, two photodiode arrays and a photon-beam position monitor. Longitudinal bunch structure is also investigated with a fast photodiode detector and a picosecond streak camera. On the other hand, the soft X-ray imaging system is under construction to measure beam sizes with negligible diffraction-limited error. The X-ray image optics consist of a flat cooled mirror and two spherical focusing mirrors.


Sign in / Sign up

Export Citation Format

Share Document