Parallel detection electron spectrometer using quadrupole lenses

摘要: Abstract The design and performance of a parallel detection electron energy loss spectrometer utilizing several new elements are described. system uses three electromagnetic quadrupole lenses to transform the spectrum produced by single magnetic sector into magnified suitable for detection, detects with single-crystal YAG scintillator, which is fiber-optically coupled either 512-channel or 1024-channel photodiode detector. interfaced computer via direct memory access, it possible read out entire spectra in 6.1 ms. cooled -30°C, noise due dark current only begins limit detector integration times longer than 100 s. capable achieving detective quantum efficiencies higher 0.25 over eight decades intensities interest EELS carried transmission microscope. optimum operation described theoretical limits discussed. Examples results from standard test specimens given, most probable future briefly