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

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.

The spacecraft wake as a tool to detect cold ions: Turning a problem into a feature

2021 ◽  
Author(s):  
Mats André ◽  
Anders I. Eriksson ◽  
Yuri V. Khotyaintsev ◽  
Sergio Toledo-Redondo
Keyword(s):  
Electric Field ◽  
Plasma Parameters ◽  
Double Probe ◽  
Positive Ions ◽  
Collisionless Plasmas ◽  
Mass Outflow ◽  
Wake Effects ◽  
In Situ Observations ◽  
Positively Charged

<p>Wakes behind scientific spacecraft caused by supersonic drifting ions is common in collisionless plasmas. Such wakes change the local plasma conditions and disturb in situ observations of the geophysical plasma parameters. We concentrate on observations of the electric field with double-probe instruments. Sometimes the wake effects are caused by the spacecraft body, are minor and easy to detect, and can be compensated for in a reasonable way. We show an example from the Cluster spacecraft in the solar wind. Sometimes the effects are caused by an electrostatic structure around a positively charged spacecraft causing an enhanced wake and major effects on the local plasma. Here observations of the geophysical electric field with the double-probe technique becomes impossible. Rather, the wake can be used to detect the presence of cold positive ions. Together with other instruments, also the cold ion flux can be estimated. We discuss such examples from the Cluster spacecraft in the magnetospheric lobes. For an intermediate range of parameters, when the drift energy of the ions is comparable to the equivalent charge of the spacecraft, also the charged wire booms of a double-probe instrument must be taken into account to extract useful information from the observations. We show an example from the MMS spacecraft near the magnetopause. With understanding of the physics causing wakes behind spacecraft, the local effects can sometimes be compensated for. When this is not possible, sometimes entirely new geophysical parameters can be estimated. An example is the flux of cold positive ions, constituting a major part of the mass outflow from planet Earth, using electric and magnetic field instruments on a spacecraft charged due to photoionization</p><p> </p>

The Channel Electron Multiplier as an Alpha Detector

1968 ◽  
Vol 15 (1) ◽  
pp. 498-502 ◽  
Author(s):  
W. C. Kaiser ◽  
W. W. Managan ◽  
T. A. Mayer
Keyword(s):  
Channel Electron Multiplier ◽  
Electron Multiplier

scholarly journals Performance of a triple-GEM demonstrator in pp collisions at the CMS detector

2021 ◽  
Vol 16 (11) ◽  
pp. P11014
Author(s):  
M. Abbas ◽  
M. Abbrescia ◽  
H. Abdalla ◽  
A. Abdelalim ◽  
S. AbuZeid ◽  
...  
Keyword(s):  
Hadron Collider ◽  
Preliminary Investigation ◽  
Operational Experience ◽  
Detector Performance ◽  
Proton Proton ◽  
Background Rate ◽  
Electron Multiplier ◽  
Gem Detector ◽  
Gem Detectors

Abstract After the Phase-2 high-luminosity upgrade to the Large Hadron Collider (LHC), the collision rate and therefore the background rate will significantly increase, particularly in the high η region. To improve both the tracking and triggering of muons, the Compact Muon Solenoid (CMS) Collaboration plans to install triple-layer Gas Electron Multiplier (GEM) detectors in the CMS muon endcaps. Demonstrator GEM detectors were installed in CMS during 2017 to gain operational experience and perform a preliminary investigation of detector performance. We present the results of triple-GEM detector performance studies performed in situ during normal CMS and LHC operations in 2018. The distribution of cluster size and the efficiency to reconstruct high pT muons in proton-proton collisions are presented as well as the measurement of the environmental background rate to produce hits in the GEM detector.

A test apparatus for secondary ion mass spectrometry

1983 ◽  
Vol 61 (4) ◽  
pp. 535-542 ◽  
Author(s):  
N. Klaus ◽  
J. D. Brown
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Low Cost ◽  
Ion Source ◽  
Channel Electron Multiplier ◽  
Electron Multiplier ◽  
Spherical Source ◽  
Ion Mass Spectrometry ◽  
Cylindrical Source ◽  
Secondary Ion

A low cost test device for secondary ion mass spectrometry (SIMS) components is described. It consists of a turbomolecular pumped vessel containing an insulated sample stage on an x−y manipulator, extraction optics, quadrupole mass filter, and channel electron multiplier. The construction and characteristics of a cylindrical and a spherical saddlefield ion source are described. The output of the cylindrical source is 10−4 A cm−2 whereas that of the spherical source is in the order of 10−3 A cm−2 at voltages up to 9 kV and at a beam divergence of 4°.

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