Understanding the limits to sensitivity in EBSD detectors and implications for direct electron detection

Cells interact with their extracellular environments by means of a variety of cellular adhesion molecules (CAM) and surface ligands. In many instances, CAMs interact in a sequential temporal fashion which suggests that these adhesion molecules may occupy or be polarized to various membrane microdomains on the cell surface. Detection of CAMs can be accomplished by a variety of methods including immunofluorescent microscopy and flow cytometry, and by the use of immunocytochemical markers (i.e. colloidal gold) in electron microscopy. The development of high resolution field emission SEM in the mid 1980's and the Autrata modification of the YAG detector for backscatter electron detection at low voltage has greatly facilitated the recognition of colloidal gold probes for detection of surface CAMs. Low voltage FESEM with Bse imaging provides increased resolution of cell surface topography (~3nm at 3-4 keV) which can be observed in 3-dimensions, and simultaneously permits detection/high spatial resolution of immunogold label by atomic number contrast.

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Yag Single Crystals for Scintillators of Stem

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100179580 ◽

1990 ◽

Vol 48 (1) ◽

pp. 166-167

Author(s):

M. Hibino ◽

K. Irie ◽

R. Autrata ◽

P. schauer

Keyword(s):

Single Crystals ◽

Yttrium Aluminum Garnet ◽

Light Guide ◽

Detection System ◽

Polished Surface ◽

Detective Quantum Efficiency ◽

Backscattered Electrons ◽

Electron Detection ◽

Yttrium Aluminum ◽

Phosphor Screens

Although powdered phosphor screens are usually used for scintillators of STEM, it has been found that the phosphor screen of appropriate thickness should be used depending on the accelerating voltage, in order to keep high detective quantum efficiency. 1 It has been also found that the variation in sensitivity, due to granularity of phosphor screens, makes the measurement of fine electron probe difficult and that the sensitivity reduces with electron irradiation specially at high voltages.In order to find out a preferable scintillator for STEM, single crystals of YAG (yttrium aluminum garnet), which are used for detecting secondary and backscattered electrons in SEM were investigated and compared with powdered phosphor screens, at the accelerating voltages of 100kV and 1 MV. A conventional electron detection system, consisting of scintillator, light guide and PMT (Hamamatsu Photonics R268) was used for measurements. Scintillators used are YAG single crystals of 1.0 to 3.2mm thicknesses (with surfaces matted for good interface to the light guide) and of 0.8mm thickness (with polished surface), and powdered P-46 phosphor screens of 0.07mm and 1.0mm thicknesses for 100kV and 1MV, respectively. Surfaces on electron-incidence side of all scintillators are coated with reflecting layers.

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Single-electron detection utilizing coupled nonlinear microresonators

Microsystems & Nanoengineering ◽

10.1038/s41378-020-00192-4 ◽

2020 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Xuefeng Wang ◽

Xueyong Wei ◽

Dong Pu ◽

Ronghua Huan

Keyword(s):

Scientific Community ◽

Room Temperature ◽

Detection Method ◽

Single Electron ◽

Nonlinear Coupling ◽

Electron Charge ◽

Micromechanical Resonators ◽

Charge Detection ◽

Simple Strategy ◽

Electron Detection

Abstract Since the discovery of the electron, the accurate detection of electrical charges has been a dream of the scientific community. Owing to some remarkable advantages, micro/nanoelectromechanical system-based resonators have been used to design electrometers with excellent sensitivity and resolution. Here, we demonstrate a novel ultrasensitive charge detection method utilizing nonlinear coupling in two micromechanical resonators. We achieve single-electron charge detection with a high resolution up to 0.197 ± 0.056 $${\mathrm{e}}/\sqrt {{\mathrm{Hz}}}$$ e / Hz at room temperature. Our findings provide a simple strategy for measuring electron charges with extreme accuracy.

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