Bremsstrahlung Secondary Electron

Radiation, Secondary—A particle or ray that is produced when the primary radiation interacts with a material, and which has sufficient energy to produce its own ionization, such as bremsstrahlung or electrons knocked from atomic orbitals with enough energy to then produce ionization (see Delta Rays). 

QTLC Quantitative thin-layer SEB Secondary electron Bremsstrahlung... 

A disadvantage of PIXE is the limitation of sensitivity due to bremsstrahlung of secondary electrons produced by the proton beam. The most serious handicap for the wide use of the method however is the necessity to perform the analysis in laboratories where accelerators or cyclotrones are available. 

The major problem encountered in APS is the signal-to-noise ratio. In the SXAPS, broad-band noise is present due to Bremsstrahlung photons, and this increases steadily with the primary electron energy [45]. In AEAPS, the yield of low energy secondary electrons k not a simple... 

Secondary Electron Bremsstrahlung (SEB) - cause of low energy background and is produced by the secondary electrons ejected from the target atoms during irradiations. 

A consequence of absorption of X rays is the inner shell ionization of the absorbing atoms and the subsequent generation of characteristic X rays from the absorbing atoms, called secondary fluorescence, which raises the generated intensity over that produced by the direct action of the beam electrons. Secondary fluorescence can be induced by both characteristic and bremsstrahlung X rays. Both effects are compo-sitionally dependent. 

In bulk samples, X-ray yields need to be adjusted by the so-called "ZAF" correction. Z stands for the element number (heavier elements reduce the electron beam intensity more than lighter elements, because they are more efficient back-scatterers), A for absorption (different elements have different cross sections for X-ray absorption), and F for secondary fluorescence (the effect described above). Corrections are much less important when the sample is a film with a thickness of 1 pm or less, because secondary effects are largely reduced. The detection limit is set by the accuracy with which a signal can be distinguished from the bremsstrahlung background. In practice, this corresponds to about 100 ppm for elements heavier than Mg. 

Several different types of source have been employed for the excitation of characteristic X-ra-diation, including those based on electrons, X rays, ) rays, protons, and synchrotron radiation. Sometimes a bremsstrahlung X-ray source is used to generate specific X-radiation from an intermediate pure element sample, called a secondary flu-... 

From isotopes decaying in P -mode, high-energy electrons ranging from several keV to MeV are emitted from the nucleus. The electrons interact with the matter and bremsstrahlung is produced. Most P -sources are used for secondary target excitation. 

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