Development of Large Crystal Size Nuclear Emulsion for Cosmic-ray Radiography

Moissanite, SiC, is an uncommon accessory mineral that forms under low oxygen fugacity. Here, we analyze natural SiC from a Miocene tuff-sandstone using synchrotron Laue microdiffraction and Raman spectroscopy, in order to better understand the SiC phases and formation physics. The studied crystals of SiC consist of 4H- and 6H-SiC domains, formed from either, continuous growth or, in one case, intergrown, together with native Si. The native Si is polycrystalline, with a large crystal size relative to the analytical beam dimensions (>1–2 μm). We find that the intergrown region shows low distortion or dislocation density in SiC, but these features are comparatively high in Si. The distortion/deformation observed in Si may have been caused by a mismatch in the coefficients of thermal expansion of the two materials. Raman spectroscopic measurements are discussed in combination with our Laue microdiffraction results. Our results suggest that these SiC grains likely grew from an igneous melt.

Download Full-text

Isotopes of Cosmic Ray Elements from Neon to Nickel

Symposium - International Astronomical Union ◽

10.1017/s0074180900074349 ◽

1981 ◽

Vol 94 ◽

pp. 33-34

Author(s):

C. J. Waddington ◽

P. S. Freier ◽

R. K. Fickle ◽

N. R. Brewster

Keyword(s):

Total Energy ◽

Nuclear Emulsion ◽

Cosmic Ray ◽

Mass Resolution ◽

Residual Range ◽

Charge Resolution

We are reporting here on the results obtained from a balloon exposure of a cosmic ray detector flown in 1977. This detector, described elsewhere, Gilman and Waddington (1975), Young (1979), measures elemental charge from scintillation and Cherenkov signals and mass from Cherenkov and total energy determined from a measure of residual range in nuclear emulsion. The charge resolution obtained ranged from 0.19 to 0.21 charge units between neon and nickel. This resolution was sufficient to ensure that all but a few percent of the nuclei were correctly identified, even for those elements of low abundance that have neighbors with high abundances, such as Cl or Al. The mass resolution obtained for those nuclei that stopped in the emulsions ranged from 0.40 to 0.70 amu for A between 20 and 60 amu. This was not adequate to uniquely resolve neighboring mass peaks in many cases, but was adequate to draw a number of conclusions regarding many of the more abundant elements.

Download Full-text

COSMIC RAY PHENOMENA AT MINIMUM IONIZATION IN A NEW NUCLEAR EMULSION HAVING A FINE GRAIN, MADE IN THE LABORATORY

Canadian Journal of Physics ◽

10.1139/p54-057 ◽

1954 ◽

Vol 32 (8) ◽

pp. 538-554 ◽

Cited By ~ 12

Author(s):

Pierre Demers

Keyword(s):

Grain Size ◽

Nuclear Emulsion ◽

Electron Pair ◽

Cosmic Ray ◽

Silver Bromide ◽

Positive Identification ◽

Fine Grain ◽

Scattering Measurements ◽

Made In ◽

Grain Diameter

The preparation of a silver bromide emulsion in the form of baseless sheets and their use in thick homogeneous stacks are described. In these sheets, a suitable development brings out minimum ionization tracks with a grain diameter 0.1 to 0.2 μ, and a linear grain density of 15 per 100 μ. The sequence of observations which led to the positive identification of minimum tracks is discussed. Short recoils and delta rays are visible, and excellent discrimination is available at all ionizing powers. The influence of grain size on fog is analyzed.Several cosmic ray phenomena containing minimum tracks are presented: single tracks, hard showers, πμe events, and an electron pair. Distortion is very small, and it is shown that the small grain size renders feasible better scattering measurements on higher energy particles. With this emulsion, nearly every possible measurement should become feasible with greater accuracy.

Download Full-text

Metamorphic and Metasomatic Kyanite-Bearing Mineral Assemblages of Thassos Island (Rhodope, Greece)

Minerals ◽

10.3390/min9040252 ◽

2019 ◽

Vol 9 (4) ◽

pp. 252 ◽

Cited By ~ 2

Author(s):

Tarantola ◽

Voudouris ◽

Eglinger ◽

Scheffer ◽

Trebus ◽

...

Keyword(s):

Crystal Size ◽

Near Infrared ◽

Coarse Grained ◽

Fluid Circulation ◽

Large Crystal ◽

Northern Greece ◽

Quartz Veins ◽

Mineral Assemblages ◽

Mineral Compositions ◽

Host Rocks

The Trikorfo area (Thassos Island, Rhodope massif, Northern Greece) represents a unique mineralogical locality with Mn-rich minerals including kyanite, andalusite, garnet and epidote. Their vivid colors and large crystal size make them good indicators of gem-quality materials, although crystals found up to now are too fractured to be considered as marketable gems. The dominant lithology is represented by a garnet–kyanite–biotite–hematite–plagioclase ± staurolite ± sillimanite paragneiss. Thermodynamic Perple_X modeling indicates conditions of ca. 630–710 °C and 7.8–10.4 kbars. Post-metamorphic metasomatic silicate and calc-silicate (Mn-rich)-minerals are found within (i) green-red horizons with a mineralogical zonation from diopside, hornblende, epidote and grossular, (ii) mica schists containing spessartine, kyanite, andalusite and piemontite, and (iii) weakly deformed quartz-feldspar coarse-grained veins with kyanite at the interface with the metamorphic gneiss. The transition towards brittle conditions is shown by Alpine-type tension gashes, including spessartine–epidote–clinochlore–hornblende-quartz veins, cross-cutting the metamorphic foliation. Kyanite is of particular interest because it is present in the metamorphic paragenesis and locally in metasomatic assemblages with a large variety of colors (zoned blue to green/yellow-transparent and orange). Element analyses and UV-near infrared spectroscopy analyses indicate that the variation in color is due to a combination of Ti4+–Fe2+, Fe3+ and Mn3+ substitutions with Al3+. Structural and mineralogical observations point to a two-stage evolution of the Trikorfo area, where post-metamorphic hydrothermal fluid circulation lead locally to metasomatic reactions from ductile to brittle conditions during Miocene exhumation of the high-grade host-rocks. The large variety of mineral compositions and assemblages points to a local control of the mineralogy and fO2 conditions during metasomatic reactions and interactions between hydrothermal active fluids with surrounding rocks.

Download Full-text

Nuclear emulsion with excellent long-term stability developed for cosmic-ray imaging

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2020.163850 ◽

2020 ◽

Vol 966 ◽

pp. 163850 ◽

Cited By ~ 1

Author(s):

Akira Nishio ◽

Kunihiro Morishima ◽

Ken-ichi Kuwabara ◽

Tetsuo Yoshida ◽

Takeshi Funakubo ◽

...

Keyword(s):

Nuclear Emulsion ◽

Cosmic Ray ◽

Term Stability ◽

Long Term Stability

Download Full-text

Digital Archives for Nuclear Emulsion Data

EPJ Web of Conferences ◽

10.1051/epjconf/201920813003 ◽

2019 ◽

Vol 208 ◽

pp. 13003

Author(s):

Koichi Kodama ◽

Takehiro Kamiya ◽

Masakatsu Ichimura ◽

Mitsuhiro Nakamura

Keyword(s):

Preliminary Data ◽

Nuclear Emulsion ◽

Cosmic Ray ◽

Current Status ◽

Accelerator Physics ◽

Digital Archives ◽

Significant Progress

Digital archives for nuclear emulsion data of past experiments, such as in cosmic-ray and accelerator physics, is being studied and prepared. Significant progress of HTS, which is an automatic read-out system for tracks recorded in emulsion, is achieving a read-out speed of about 1m2/hour and opens a possibility to read all tracks recorded in emulsion of past experiments. Current status of our first trial with RUNJOB emulsion plates is reported. Till now, the top-most 10 plates had been scanned by HTS and preliminary data is presented.

Download Full-text

Lead-free/rare earth-free Green-light-emitting crystal based on organic-inorganic hybrid [(C10H16N)2][MnBr4] with high emissive quantum yields and large crystal size

Journal of Molecular Structure ◽

10.1016/j.molstruc.2018.01.093 ◽

2018 ◽

Vol 1161 ◽

pp. 262-266 ◽

Cited By ~ 18

Author(s):

Xing-Wei Cai ◽

Yu-Yuan Zhao ◽

Hong Li ◽

Cui-Ping Huang ◽

Zhen Zhou

Keyword(s):

Rare Earth ◽

Crystal Size ◽

Green Light ◽

Lead Free ◽

Quantum Yields ◽

Large Crystal ◽

Inorganic Hybrid ◽

Light Emitting

Download Full-text

Gigantism in unique biogenic magnetite at the Paleocene–Eocene Thermal Maximum

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0803634105 ◽

2008 ◽

Vol 105 (46) ◽

pp. 17648-17653 ◽

Cited By ~ 49

Author(s):

Dirk Schumann ◽

Timothy D. Raub ◽

Robert E. Kopp ◽

Jean-Luc Guerquin-Kern ◽

Ting-Di Wu ◽

...

Keyword(s):

Electron Microscopy ◽

Global Warming ◽

Crystal Size ◽

Magnetotactic Bacteria ◽

Iron Bioavailability ◽

Electron Holography ◽

Large Crystal ◽

Biogenic Magnetite ◽

Thermal Maximum ◽

Suboxic Zone

We report the discovery of exceptionally large biogenic magnetite crystals in clay-rich sediments spanning the Paleocene–Eocene Thermal Maximum (PETM) in a borehole at Ancora, NJ. Aside from previously described abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite up to 4 μm long and hexaoctahedral prisms up to 1.4 μm long. Similar to magnetite produced by magnetotactic bacteria, these single-crystal particles exhibit chemical composition, lattice perfection, and oxygen isotopes consistent with an aquatic origin. Electron holography indicates single-domain magnetization despite their large crystal size. We suggest that the development of a thick suboxic zone with high iron bioavailability—a product of dramatic changes in weathering and sedimentation patterns driven by severe global warming—drove diversification of magnetite-forming organisms, likely including eukaryotes.

Download Full-text