Characteristics of an Electron Multiplier in the Detection of Positive Ions

1954 ◽  
Vol 25 (11) ◽  
pp. 1112-1115 ◽  
Author(s):  
C. F. Barnett ◽  
G. E. Evans ◽  
P. M. Stier
Keyword(s):  
Electron Multiplier ◽  
Positive Ions

Spiral Electron Multiplier Operation Characteristics Using Positive Ions

1972 ◽  
Vol 43 (9) ◽  
pp. 1327-1330 ◽  
Author(s):  
Wentworth E. Potter ◽  
Konrad Mauersberger
Keyword(s):  
Electron Multiplier ◽  
Positive Ions ◽  
Operation Characteristics

scholarly journals In situ absolute calibration of a channel electron multiplier for detection of positive ions

1995 ◽  
Vol 66 (1) ◽  
pp. 67-71 ◽  
Author(s):  
D. W. Savin ◽  
L. D. Gardner ◽  
D. B. Reisenfeld ◽  
A. R. Young ◽  
J. L. Kohl
Keyword(s):  
Absolute Calibration ◽  
Channel Electron Multiplier ◽  
Electron Multiplier ◽  
Positive Ions

Detection Efficiency of a Continuous Channel Electron Multiplier for Positive Ions

1967 ◽  
Vol 38 (10) ◽  
pp. 1477-1481 ◽  
Author(s):  
Clifford N. Burrous ◽  
Albert J. Lieber ◽  
Vladimir T. Zaviantseff
Keyword(s):  
Detection Efficiency ◽  
Channel Electron Multiplier ◽  
Electron Multiplier ◽  
Positive Ions

Channel electron multiplier and channelplate efficiencies for detecting positive ions

2005 ◽  
Vol 76 (9) ◽  
pp. 093305 ◽  
Author(s):  
M. Krems ◽  
J. Zirbel ◽  
M. Thomason ◽  
R. D. DuBois
Keyword(s):  
Channel Electron Multiplier ◽  
Electron Multiplier ◽  
Positive Ions

Design of a high-resolution mass spectrometer for studying the photodissociation of organic ions in the gas phase

1981 ◽  
Vol 374 (1759) ◽  
pp. 461-473 ◽  
Keyword(s):  
Mass Spectrometer ◽  
Ion Source ◽  
Operating Conditions ◽  
Electron Multiplier ◽  
Electric Sector ◽  
Positive Ions ◽  
Free Region ◽  
Field Free Region ◽  
Ion Laser ◽  
Double Focusing

The design and operating conditions of an apparatus to study photodissociation of ions is described. Ions in a large, double-focusing, mass spectrometer are irradiated with photons from an argon-ion laser. A path length of 706 mm for interaction between the ion and laser beams is obtained by passing the radiation through the ion source and then along the same path as that followed by the ions in the first field-free region of the mass spectrometer. By scanning the voltage of the electric sector, different fragment ions resulting from photodissociation are transmitted in turn to an electron multiplier. They are distinguished from ions resulting from unimolecular dissociation by mechanically chopping the laser beam and using the technique of phase-sensitive detection. The photodissociations of the molecular, positive ions of the three isomers of nitrotoluene have been investigated. It is found that, after excitation of the ions with 2.541 eV photons, the resulting fragmentation pathways are different from those for the corresponding unimolecular dissociations.

A New AID for Interpolating and Assessing Collision Strengths and Rate Coefficients

1988 ◽  
Vol 102 ◽  
pp. 107-110
Author(s):  
A. Burgess ◽  
H.E. Mason ◽  
J.A. Tully
Keyword(s):  
Significant Loss ◽  
Impact Excitation ◽  
Rate Coefficients ◽  
Electron Impact Excitation ◽  
Graphical Display ◽  
Practical Procedure ◽  
Positive Ions ◽  
Allowed Transition ◽  
Computational Errors ◽  
Existing Data

AbstractA new way of critically assessing and compacting data for electron impact excitation of positive ions is proposed. This method allows one (i) to detect possible printing and computational errors in the published tables, (ii) to interpolate and extrapolate the existing data as a function of energy or temperature, and (iii) to simplify considerably the storage and transfer of data without significant loss of information. Theoretical or experimental collision strengths Ω(E) are scaled and then plotted as functions of the colliding electron energy, the entire range of which is conveniently mapped onto the interval (0,1). For a given transition the scaled Ω can be accurately represented - usually to within a fraction of a percent - by a 5 point least squares spline. Further details are given in (2). Similar techniques enable thermally averaged collision strengths upsilon (T) to be obtained at arbitrary temperatures in the interval 0 < T < ∞. Application of the method is possible by means of an interactive program with graphical display (2). To illustrate this practical procedure we use the program to treat Ω for the optically allowed transition 2s → 2p in ArXVI.

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.

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