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Auger effect in medicine

Auger effect in medicine. The Auger effect refers to the ejection of electrons from an atom following ionization of inner-shell electrons It is usually initiated by X-ray photoionization of K-shell or L-shell electrons.

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Auger effect in medicine

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  1. Auger effect in medicine • The Auger effect refers to the ejection of electrons from an atom following ionization of inner-shell electrons • It is usually initiated by X-ray photoionization of K-shell or L-shell electrons. • In heavy high-Z atoms up to 20 Auger electrons may be ejected (see Table 5.3 of Atomic Astrophysics and Spectroscopy (AAS) Pradhan and Nahar, Cambridge University Press, 2011) • Special cases of Auger transitions are known as Coster-Kronig and Super-Coster-Kronig transitions(see Fig. 5.11 of AAS , as animated in the second slide) • It may be highly effective in cancer treatment using high-Z material or nanoparticles delivered to the tumor and irradiated by X-rays (animated in the third slide) • Auger electrons from high-Z atoms can kill malignant cells

  2. Auger Radiation and Electron cascades (“Atomic Astrophysics and Spectroscopy”, Anil Pradhan & Sultana Nahar, Cambridge U. Press 2011) This leaves us with four vacancies in the M-shell that will continue this increasing cascade of electron ejection throughout the atom We now have 2 vacancies in the L-shell that will be filled with M-shell electrons The two M-shell electrons can emit two photons, which can then knock out two more M-shell electrons Incident photon hits the K-shell The L-shell electron then emits a Kα photon, which can leave as fluorescence, or knock out another L-shell electron The vacancy in the K shell is filled with an L-shell electron, creating a new vacancy The electron gets ejected, leaving a vacancy Electron absorbs the photon

  3. Monoenergetic X-Ray Irradiation of High-Z Nanoparticles for Imaging and Therapy: “Resonant Nano-Plasma Theranostics (RNPT)”(Pradhan et. al., Proc. XVth Int. Conf. Comp. Rad., V.2, p89, 2007) Particles return to the ground state and emit light Burst of monochromatic x-rays Particles absorb X-rays and excite/ionize X-rays that are transmitted are detected

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