XRF (X-ray fluorescence) is a non-destructive analytical technique used to determine the elemental composition of materials. XRF analyzers determine the chemistry of a sample by measuring the fluorescent (or secondary) X-ray emitted from a sample when it is excited by a primary X-ray source. Each of the elements present in a sample produces a set of characteristic fluorescent X-rays (“a fingerprint”) that is unique for that specific element, which is why XRF spectroscopy is an excellent technology for qualitative and quantitative analysis of material composition.
The X-ray fluorescence process
A solid or a liquid sample is irradiated with high energy X-rays from a controlled X-ray tube.
When an atom in the sample is struck with an X-ray of sufficient energy (greater than the atom’s K or L shell binding energy), an electron from one of the atom’s inner orbital shells is dislodged.
The atom regains stability, filling the vacancy left in the inner orbital shell with an electron from one of the atom’s higher energy orbital shells.
The electron drops to the lower energy state by releasing a fluorescent X-ray. The energy of this X-ray is equal to the specific difference in energy between two quantum states of the electron. The measurement of this energy is the basis of XRF analysis
PCGS CoinFacts is an in-depth online encyclopedia of United States coins. As the most comprehensive database for U.S. coins on the internet, CoinFacts is a collector’s leading educational resource for buying, selling, and collecting coins.
CoinFacts includes historical narratives to help you learn about the coins you love accompanied by relevant and up-to-date collectible coin value information. Each section provides numismatists of all levels with a host of information about each coin. Details include PCGS Coin Price Guide values, coin population data by grade, known coin varieties, public coin auction results, and high-resolution PCGS TrueView coin photographs.
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