Development of ultra high resolution analytical electron microscope ISI-EM-002A

1983 ◽  
Vol 41 ◽  
pp. 312-313 ◽  
Author(s):  
T. Yanaka ◽  
A. Yonezawa ◽  
K. Oosawa ◽  
T. Iwaki ◽  
S. Suzuki ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Voltage ◽  
Electron Gun ◽  
Objective Lens ◽  
Magnetic Circuits ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Mode 3 ◽  
High Voltage Generator

Total design concept of EM-002A is to realize the following essential performance, that is, 1) attainment to ultimate high resolution as the conventional electron microscope, 2) complete compatibility of the high resolution mode and the analytical mode, 3) identification of the analyzed region and the observed image with atomic-level resolution, 4) observation of ultra fine structure of the biological specimen with maximum high contrast and so on.[Electron source] Accelerating voltage ranges from 20kV to 120kV in 6 steps Double Cockroft-Walton circuit is used as the high voltage generator and the high frequency ripple voltage is reduced to 0.1V. Electron gun assembly is composed of high voltage alumina insulator, whose shape is so well designed as to suppress micro-discharge to the negligible order.[Objective lens and specimen chamber] The objective lens is a strong symmetrical lens where the specimen chamber is located between the symmetrical upper and lower objective lens magnetic circuits. The objective lens has two powerful pole pieces, one being used for the ultra high resolution mode and the other for the standard mode.

High Resolution Side-Entry Goniometer

1980 ◽  
Vol 38 ◽  
pp. 56-57
Author(s):  
T. Honda ◽  
H. Watanabe ◽  
K. Ohi ◽  
E. Watanabe ◽  
Y. Kokubo
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
High Resolution ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Resolution Limit ◽  
Tilting Angle ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
High Resolution Images

An analytical electron microscope equipped with a side-entry goniometer (SEG) has recently become more widespread than a conventional electron microscope by the following reasons: (1) a variety of specimen holders, (2) large tilting angle with eucentricity. However, the resolution of SEG-system is about 0.4 nm, whereas the resolution of 0.25 nm or less can be obtained by an electron microscope equipped with a top-entry goniometer (TEG)1). Factors determining the resolution of an electron microscope are (1) the aberration coefficients of the objective lens, (2) stability of exciting currents, (3) illumination angle of the electron beam on the specimen, (4) energy spread of the electron beam, and ( 5) vibration and specimen drift. It has been usually difficult to observe high resolution images during use of the SEG system, because of the aberration coefficients of the objective lens, vibration and specimen drift. In order to obtain a resolution of less than 0.3 nm with SEG system at 200 kV, both of spherical and chromatic aberration coefficients should be reduced less than 2 mm. Moreover, relative amplitude of vibration between the specimen and pole pieces should be less than a half value of resolution limit. The image drift should be less than 0.02 nm/sec, because the exposure time usually required for photographing a high resolution image is about 5 second.

Development of 200kV ultrahigh-resolution analytical electron microscope

1989 ◽  
Vol 47 ◽  
pp. 108-109
Author(s):  
T. Kaneyama ◽  
M. Naruse ◽  
Y. Ishida ◽  
M. Kersker
Keyword(s):  
Electron Microscope ◽  
Optical Constants ◽  
Materials Science ◽  
Objective Lens ◽  
The Finite Element Method ◽  
Ultrahigh Resolution ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Characteristic Features ◽  
Better Than

In the field of materials science, the importance of the ultrahigh resolution analytical electron microscope (UHRAEM) is increasing. A new UHRAEM which provides a resolution of better than 0.2 nm and allows analysis of a few nm areas has been developed. [Fig. 1 shows the external view] The followings are some characteristic features of the UHRAEM.Objective lens (OL)Two types of OL polepieces (URP for ±10' specimen tilt and ARP for ±30' tilt) have been developed. The optical constants shown in the table on the next page are figures calculated by the finite element method. However, Cs was experimentally confirmed by two methods (namely, Beam Tilt method and Krivanek method) as 0.45 ∼ 0.50 mm for URP and as 0.9 ∼ 1.0 mm for ARP, respectively. Fig. 2 shows an optical diffractogram obtained from a micrograph of amorphous carbon with URP under the Scherzer defocus condition. It demonstrates a resolution of 0.19 nm and a Cs smaller than 0.5 mm.

Development of high-performance objective lens polepiece for ultrahigh resolution Analytical Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 254-255
Author(s):  
K. Fukushima ◽  
T. Kaneyama ◽  
F. Hosokawa ◽  
H. Tsuno ◽  
T. Honda ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Performance ◽  
Open Space ◽  
Materials Science ◽  
Objective Lens ◽  
Ultrahigh Resolution ◽  
Science Field ◽  
Specimen Holder ◽  
Analytical Electron ◽  
Analytical Electron Microscope

Recently, in the materials science field, the ultrahigh resolution analytical electron microscope (UHRAEM) has become a very important instrument to study extremely fine areas of the specimen. The requirements related to the performance of the UHRAEM are becoming gradually severer. Some basic characteristic features required of an objective lens are as follows, and the practical performance of the UHRAEM should be judged by totally evaluating them.1) Ultrahigh resolution to resolve ultrafine structure by atomic-level observation.2) Nanometer probe analysis to analyse the constituent elements in nm-areas of the specimen.3) Better performance of x-ray detection for EDS analysis, that is, higher take-off angle and larger detection solid angle.4) Higher specimen tilting angle to adjust the specimen orientation.To attain these requirements simultaneously, the objective lens polepiece must have smaller spherical and chromatic aberration coefficients and must keep enough open space around the specimen holder in it.

Combined Use of Structure Imaging and Microanalysis in Structure-Composition Analysis By A 400-KV High-Resolution Analytical Electron Microscope

1985 ◽  
Vol 43 ◽  
pp. 228-229
Author(s):  
Yoshio Bando ◽  
Yoshizo Kitami ◽  
Mamoru Mitcmo
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Image Resolution ◽  
Composition Analysis ◽  
Transmission Electron ◽  
Resolution Observation ◽  
Composition Determination ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Normal Transmission

One of the limitations in the use of the conventional analytical electron microscope (AEM) with lower voltages of 100 to 200 kV is based on its poor image resolution compared to normal transmission electron microscope. Because of this, it is difficult to carry out structure determination by directly observing individual atom arrangements in crystals. However, a new AEM with an intermediate voltage of 400 kV (JEM-4000EX, TEMSCAN) is fully capable of high resolution observation under equipment of an energy dispersive x-ray spectrometer (EDS) and an electron energy loss spectrometer (EELS). The present paper shows crystal structure images of sialon polytypes and corresponding EDS and EELS spectra, and describes the usefullness of combined techniques of structure imaging and microanalysis in structure-composition determination.

X-ray detection performance of a 300KV field-emission Analytical Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 250-251
Author(s):  
C. E. Lyman ◽  
J. I. Goldstein ◽  
D.B. Williams ◽  
D.W. Ackland ◽  
S. von Harrach ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Detection Performance ◽  
Electron Gun ◽  
X Rays ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope

A major goal of analytical electron micrsocopy (AEM) is to detect small amounts of an element in a given matrix at high spatial resolution. While there is a tradeoff between low detection limit and high spatial resolution, a field emission electron gun allows detection of small amounts of an element at sub-lOnm spatial resolution. The minimum mass fraction of one element measured in another is proportional to [(P/B)·P]-1/2 where the peak-to-background ratio P/B and the peak intensity P both must be high to detect the smallest amount of an element. Thus, the x-ray detection performance of an analytical electron microscope may be characterized in terms of standardized measurements of peak-to-background, x-ray intensity, the level of spurious x-rays (hole count), and x-ray detector performance in terms of energy resolution and peak shape.This paper provides measurements of these parameters from Lehigh’s VG Microscopes HB-603 field emission AEM. This AEM was designed to provide the best x-ray detection possible.

Development of a 300 kV field emission TEM

1993 ◽  
Vol 51 ◽  
pp. 1080-1081
Author(s):  
Y. Ishida ◽  
Y. Bando ◽  
Y. Kitami ◽  
T. Tomita ◽  
M. Kersker
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Atomic Layer ◽  
Electron Gun ◽  
Emission Current ◽  
Long Period ◽  
Current Variation ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Ultrahigh Sensitivity

The 300 kV analytical electron microscope, as compared with the 100 to 200 kV instruments, have excellent features such as the high resolution of TEM images, high P/B ratio of EDS and PEELS, and high spacial resolution in analysis.We hereby report the principal specifications of an ultrahigh sensitivity and ultrahigh resolution field emission type electron microscope, which, capable of giving full play to the above-mentioned features of the 300 kV analytical instrument, allows elemental analysis at the single atomic layer level (nm regions).Its electron gun, simply operated by CPU control, allows emission current to be obtained at the touch of a single button. As the emitter, a W (100)-TF emitter, which can be used simply, stably, and for a long period of time, is employed. After build-up, this emitter can obtain about 10 times the angular current density of the W (310) emitter. Around the emitter are provided three electrodes to make emission current variation and electrostatic lens function independent of each other.

scholarly journals Development of a 300kV ultrahigh resolution analytical electron microscope

1991 ◽  
Vol 49 ◽  
pp. 350-351
Author(s):  
Kurio Fukushima ◽  
Yoshihiro Arai ◽  
Masahiro Kawasaki ◽  
Yasushi Kokubo
Keyword(s):  
Electron Microscope ◽  
Electron Gun ◽  
External View ◽  
Ultrahigh Resolution ◽  
Science Field ◽  
Heating And Cooling ◽  
Resolution Observation ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Characteristic Features

Intended for atomic-level observation and analysis in the material science field, a 300 kV ultrahigh resolution analytical electron microscope (UHRAEM) has been newly developed on the basis of the JEM-2010, a 200 kV UHRAEM. There are two versions: the UHR version, intended for ultrahigh resolution observation with a point resolution of 0.17 nm and the multi-purpose HT version, featuring specimen tilt angles as large as± 40° , and heating and cooling holders. The external view of the instrument is shown in Fig.1. Some characteristic features of the 300 kV UHRAEM are shown as follows.Electron Gun: An extremely stable and compact 300 kV election gun is constructed with 10-stage accelerating tube. SF6 gas is used for electric insulation.

Trace Element Quantitation in Biological X-Ray Microanalysis

1998 ◽  
Vol 4 (S2) ◽  
pp. 212-213
Author(s):  
R.D. Leapman ◽  
C.R. Swyt-Thomas ◽  
D. v. Agoston ◽  
N. Pivovarova ◽  
S.B. Andrews
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Dry Weight ◽  
Limiting Factor ◽  
X Ray ◽  
Elemental Concentrations ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Counting Statistics ◽  
Edx Microanalysis

In high-resolution biological energy-dispersive x-ray (EDX) microanalysis it is often necessary to measure very low elemental concentrations. As an example, calcium, a physiologically important element, typically occurs in subcellular compartments at concentrations of 10-100 atomic parts per million (corresponding to 1-10 millimole/kg dry weight of sample) and it is ultimately desirable to measure the concentration of this element with a standard error of ±1 atomic ppm (or ± 0.1 millimole/kg). Detection of calcium in biological specimens is further complicated by the presence of relatively high levels of potassium (around 0.5 atomic % or 500 millimole/kg), which gives rise to overlap of the K Kβ and Ca Kα peaks in the EDX spectrum. Counting statistics are frequently the limiting factor for detectability, but this is not necessarily the case because in the analytical electron microscope it is possible to collect spectra for long periods using a high probe current.

Development of 100 kV Field Emission Scanning Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 408-409
Author(s):  
H. Koike ◽  
Y. Harada ◽  
T. Goto ◽  
Y.Kokubo ◽  
K. Yamada ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Chemical Elements ◽  
Signal To Noise Ratio ◽  
Electron Gun ◽  
The Past ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Scanning Electron

During the past ten years, the resolution of the CTEM has been improved to a theoretical value determined by spherical and diffraction aberrations. In the scanning electron microscope, however, the resolution is restricted by the signal-to-noise ratio. Crewe et al were the first to increase the resolution by applying a field emission source to a 35 kV scanning electron microscope, resulting in a 5 Å resolution. Owing to its prominent brightness, the feild emission electron gun promises to increase not only the resolution of STEM images, but also to realize an analytical electron microscope which identifies chemical elements, crystalline structures and chemical bonding in specimen microareas in the order of less than 100 Å.

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