Channel electron multiplier and channelplate efficiencies for detecting positive ions

Abstract

Absolute detection efficiencies for singly and multiply charged positive ions have been measured for a channelplate and for two different channel electron multipliers (CEM). The efficiencies were measured for impact energies between approximately 0.25 and 25 keV and for ion masses ranging from 14 to 132. The maximum efficiencies were found to be the same for all ions investigated and were approximately 58% for a channelplate and 89% for the CEMs. For a channelplate it is shown that the detection efficiencies for heavier ions scale to a single curve if plotted versus the impact energy divided by the square root of the ion mass. Data taken from the literature imply that lighter ions scale differently. Polynomial fitting parameters to the present efficiency curves are provided.

Characterization of ion emission of an extreme ultraviolet generating discharge produced Sn plasma

“…When the ion impact energy is sufficiently high ͑Ͼ3 keV͒ heavy ions and low mass ions are detected with equal detection efficiency. [18][19][20] From this it follows that the signal intensity of ions of different species can be compared. However, because the detection efficiency may differ for particles with different kinetic energies, only the signal of ions with equal energy and E kin Ͼ 3 keV can be analyzed.…”

Hydrogen and fluorine migration in photo-double-ionization of 1,1-difluoroethylene (1,1-C2H2F2Gaire1, Bocharova2, Sturm3 et al. 2014Phys. Rev. A41130View full textAdd to dashboardCite

“…The branching ratios are corrected for the overall detection efficiency of different channels by using the estimated detection efficiency of individual ions as mentioned in Ref. [23]. Photo-double-ionization yield as a function of threshold energy (defined as E sum subtracted from the photon energy E γ ) of the different channels of 1,1-C 2 H 2 F 2 using 40-(open symbols) and 60-eV (solid symbols) photons.…”

A simple Bragg detector design for AMS and IBA applications

“…Initially, different electron multiplier tubes (two multi-stage dynode counters: Hamamatsu EMT R5150-10, ETP AF150/14150 and one channeltron: Sjuts KBL505) were applied to detect single radiocarbon ions. Drawbacks of these detectors are a distinct dark count rate [33] and limited detection efficiencies for ions (<90%) [34], which both depend on the applied bias voltage. Dark count rates of one per minute were determined and for radiocarbon standard samples only about 60-75% of the expected 14 C count rate was measured at the lCADAS system.…”