scholarly journals Operating Characteristics of a Commercial Resistance‐Strip Magnetic Electron Multiplier

1965 ◽  
Vol 36 (1) ◽  
pp. 110-111 ◽  
Author(s):  
W. W. Hunt ◽  
K. E. McGee ◽  
M. J. Kennedy
Keyword(s):  
Operating Characteristics ◽  
Electron Multiplier ◽  
Magnetic Electron ◽  
Commercial Resistance

Resistance Strip Magnetic Electron Multiplier

1961 ◽  
Vol 32 (7) ◽  
pp. 846-849 ◽  
Author(s):  
G. W. Goodrich ◽  
W. C. Wiley
Keyword(s):  
Electron Multiplier ◽  
Magnetic Electron

Fast and Slow Afterpulsing in a Magnetic Electron Multiplier

1973 ◽  
Vol 44 (9) ◽  
pp. 1399-1400 ◽  
Author(s):  
M. E. Erskine ◽  
C. F. G. Delaney
Keyword(s):  
Electron Multiplier ◽  
Magnetic Electron

Source and Multiplier Modifications of a Time-of-Flight Mass Spectrometer to Increase Sensitivity

1964 ◽  
Vol 18 (5) ◽  
pp. 134-136 ◽  
Author(s):  
W. K. Rohwedder ◽  
E. Selke ◽  
E. D. Bitner
Keyword(s):  
Mass Spectrometer ◽  
Time Of Flight ◽  
Gas Chromatograph ◽  
Electron Multiplier ◽  
Carrier Gas ◽  
Flight Mass Spectrometer ◽  
Front End ◽  
Ionization Mode ◽  
Magnetic Electron ◽  
Instrument Sensitivity

The usefulness of a gas chromatograph and a mass spectrometer in tandem to analyze odor constituents is limited by the sensitivity of the mass spectrometer and by the large amount of helium carrier gas compared with the amount of sample A time-of-flight mass spectrometer was fitted with a tightly enclosed source and operated in a continuous ionization mode to increase instrument sensitivity A gate pulse was applied to the front end of the magnetic electron multiplier to eliminate the electrons due to the helium pulse before they reached the multiplier dynode strips This procedure prevented saturation of the multiplier by the helium carrier gas.

SEM and Auger microanalysis studies of Cu-Be dynode surfaces at each activation condition

1978 ◽  
Vol 36 (1) ◽  
pp. 524-525
Author(s):  
T. Koshikawa ◽  
Y. Fujii ◽  
E. Sugata ◽  
F. Kanematsu
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Life Time ◽  
Activation Process ◽  
Beam Diameter ◽  
Activation Temperature ◽  
Electron Multiplier ◽  
Activation Condition ◽  
Activation Conditions

The Cu-Be alloys are widely used as the electron multiplier dynodes after the adequate activation process. But the structures and compositions of the elements on the activated surfaces were not studied clearly. The Cu-Be alloys are heated in the oxygen atmosphere in the usual activation techniques. The activation conditions, e.g. temperature and O2 pressure, affect strongly the secondary electron yield and life time of dynodes.In the present paper, the activated Cu-Be dynode surfaces at each condition are investigated with Scanning Auger Microanalyzer (SAM) (primary beam diameter: 3μmϕ) and SEM. The commercial Cu-Be(2%) alloys were polished with Cr2O3 powder, rinsed in the distilled water and set in the vacuum furnance.Two typical activation condition, i.e. activation temperature 730°C and 810°C in 5x10-3 Torr O2 pressure were chosen since the formation mechanism of the BeO film on the Cu-Be alloys was guessed to be very different at each temperature from the results of the secondary electron emission measurements.

First H+ Charge-Exchange Images in the Stim.

1976 ◽  
Vol 34 ◽  
pp. 504-505
Author(s):  
Wm. H. Escovitz ◽  
T. R. Fox ◽  
R. Levi-Setti
Keyword(s):  
Charge Exchange ◽  
Neutral Component ◽  
Channel Electron Multiplier ◽  
Electron Multiplier ◽  
Neutral Particles ◽  
Charged Beam ◽  
Scanning Transmission ◽  
Contrast Mechanism ◽  
Ion Microscopy ◽  
Beam Component

Charge exchange, the neutralization of ions by electron capture as the ions traverse matter, is a well-known phenomenon of atomic physics which is relevant to ion microscopy. In conventional transmission ion microscopes, the neutral component of the beam after it emerges from the specimen cannot be focused. The scanning transmission ion microscope (STIM) enables the detection of this signal to make images. Experiments with a low-resolution 55 kV STIM indicate that the charge-exchange signal provides a new contrast mechanism to detect extremely small amounts of matter. In an early version of charge-exchange detection (fig. 1), a permanent magnet installed between the specimen and the detector (a channel electron multiplier) sweeps the charged beam component away from the detector and allows only the neutrals to reach it. When the magnet is removed, both charged and neutral particles reach the detector.

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