NEW DESIGN OF ELECTRON GUN FOR FIELD EMISSION LIGHT SOURCES WITH CARBON FIBERS CATHODE

2007 ◽  
pp. 255-258 ◽  
Author(s):  
M. YU. LESHUKOV ◽  
E.P. SHESHIN
Keyword(s):  
Field Emission ◽  
Carbon Fibers ◽  
Electron Gun ◽  
Light Sources ◽  
Emission Light

Field-emission light sources for lab-on-a-chip microdevices

2012 ◽  
Vol 60 (1) ◽  
Author(s):  
A. Górecka-Drzazga ◽  
B. Cichy ◽  
P. Szczepańska ◽  
R. Walczak ◽  
J. Dziuban
Keyword(s):  
Field Emission ◽  
Lab On A Chip ◽  
Light Sources ◽  
Emission Light

Miniature field emission light sources associated with silicon-glass microcytometer for measurements of quality of oocytes

2009 ◽  
Author(s):  
Bartlomiej Cichy ◽  
Anna Gorecka-Drzazga ◽  
Patrycja Szczepanska ◽  
Rafal Walczak ◽  
Witold Posadowski ◽  
...  
Keyword(s):  
Field Emission ◽  
Light Sources ◽  
Emission Light

scholarly journals Miniature field emission light sources for bio-chips

2009 ◽  
Vol 146 ◽  
pp. 012021
Author(s):  
Bartłomiej Cichy ◽  
Anna Górecka-Drzazga ◽  
Jan A Dziuban
Keyword(s):  
Field Emission ◽  
Light Sources ◽  
Emission Light

High-resolution scanning electron microscopy of carbon fiber

1989 ◽  
Vol 47 ◽  
pp. 704-705
Author(s):  
Deborah L. Vezie
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Carbon Fiber ◽  
Field Emission ◽  
Carbon Fibers ◽  
Low Voltage ◽  
Electron Gun ◽  
Scanning Electron

As part of an extensive study of polyacrylonitrile (PAN) and mesophase pitch-based carbon fibers, high resolution scanning electron microscopy (HRSEM) is shown to provide additional insight into understanding and modelling microstructural origins of mechanical properties of carbon fiber. Although carbon fiber has been studied extensively, no sufficiently clear relationship between structure and mechanical properties such as elastic modulus and compressive strength has yet been developed from quantitative TEM and WAXS investigations.In this study, HRSEM data of selected carbon fibers is used to illustrate the power of HRSEM to elucidate structural differences likely accounting for changes in mechanical properties not sensitively probed either by TEM or WAXS. The three-dimensional nature of SEM imaging with accompanying high resolution permits a clearer visualization and more detailed examination of regional structures within carbon fiber over two-dimensional TEM and globally averaged WAXS data.The design of the high resolution, field emission SEM permits low voltage imaging of poorly conducting samples with resolution an order of magnitude greater than a conventional tungsten hairpin filament SEM under the same operating voltage and sample preparation conditions. Although carbon fiber is a relatively conductive material, charging effects can be seen in uncoated PAN fibers above 3.0 keV in a conventional SEM. Lower accelerating voltages are necessary for uncoated imaging of these fibers, but become impractical due to degradation of conventional SEM performance at these voltages. Uncoated sample imaging is preferred to prevent conventional evaporation or sputter coating techniques from obscuring or altering the sample surface, although charging effects may then be a problem. The high resolution, field emission SEM solves these competing voltage/ charging/ resolution issues for poorly conducting materials with the very nature of its design; the high brightness of the electron gun at low voltage coupled with the “in lens” sample placement and above the objective lens detector dramatically improve the resolution of these instruments, especially at low voltage.

Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

1974 ◽  
Vol 32 ◽  
pp. 390-391
Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya
Keyword(s):  
Field Emission ◽  
Phase Contrast ◽  
Image Formation ◽  
Fresnel Diffraction ◽  
Experimental Results ◽  
Electron Gun ◽  
Scanning Microscopy ◽  
Emission Electron ◽  
Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

Optical characteristics of the hitachi HF-2000 cold field-emission TEM

1993 ◽  
Vol 51 ◽  
pp. 1076-1077
Author(s):  
L. F. Allard ◽  
E. Völkl ◽  
T. A. Nolan
Keyword(s):  
Field Emission ◽  
Recent Literature ◽  
Electron Gun ◽  
High Brightness ◽  
Condenser Lens ◽  
Illumination System ◽  
High Resolution Images ◽  
Imaging Mode ◽  
Better Than ◽  
Illuminating System

The illumination system of the cold field emission (CFE) Hitachi HF-2000 TEM operates with a single condenser lens in normal imaging mode, and with a second condenser lens excited to give the ultra-fine 1 nm probe for microanalysis. The electron gun provides a guaranteed high brightness of better than 7×l08 A/cm2/sr, more than twice the guaranteed brightness of Schottky emission guns. There have been several articles in the recent literature (e.g. refs.) which claim that the geometry of this illumination system yields a total current which is so low that when the beam is spread at low magnifications (say 10 kX), the operator must “keep his eyes glued to the binoculars” in order to see the image. It is also claimed that this illuminating system produces an isoplanatic patch (the area over which image character does not vary significantly) at high magnification which is so small that the instrument is ineffective for recording high resolution images.

Efficient Carbon Nanotube Field Emitter using Electrospun Carbon Nanofibers as a Flexible Electrode

2009 ◽  
Vol 1173 ◽  
Author(s):  
Hidetoshi Matsumoto ◽  
Kenichi Suzuki ◽  
Kazuma Tsuboi ◽  
Mie Minagawa ◽  
Akihiko Tanioka ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Carbon Fibers ◽  
Current Density ◽  
Chemical Vapor ◽  
Light Sources ◽  
Flexible Electrode ◽  
Field Emitter ◽  
Field Emitter Arrays ◽  
Thin Carbon ◽  
Cnt Field Emitter

AbstractThermal-stable, conductive, and flexible carbon fabric (CF), which is composed of thin carbon fibers prepared by electrospinning, was used for the substrate of carbon nanotube (CNT) field emitter arrays. The field emitter arrays were prepared by chemical vapor deposition (CVD). The current density-electric field characteristics revealed that the CNT field emitter arrays on CF produced a higher current density at a lower turn-on voltage compared to ones on a Si substrate. This emitter integrated with a gate electrode based on hierarchy-structured carbon materials, CNTs on CF, can be used for light sources, displays, and other electronic devices.

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