Alpha Particles
Some of the alpha particles of a defined energy are backscattered to the detector if they collide with an atomic nucleus. The physical laws for Rutherford backscattering in an angle close to 180° are conservation of energy and conservation of linear momentum. This makes it possible to calculate the mass of the nucleus hit by the alpha particle. Light elements absorb more energy of the alpha particle, while alpha particles are reflected by heavy nuclei nearly with the same energy. The energy spectrum of the scattered alpha particle shows peaks from 25% up to nearly 100% of the initial alpha particles. This spectrum makes it possible to determine the composition of the sample, especially for the lighter elements. The low backscattering rate makes it necessary for elongated irradiation, approx 10 hours.
Read more about this topic: Alpha Particle X-ray Spectrometer
Famous quotes containing the words alpha and/or particles:
“Imagination is a valuable asset in business and she has a sister, Understanding, who also serves. Together they make a splendid team and business problems dissolve and the impossible is accomplished by their ministrations.... Imagination concerning the world’s wants and the individual’s needs should be the Alpha and Omega of self-education.”
—Alice Foote MacDougall (1867–1945)
“When was it that the particles became
The whole man, that tempers and beliefs became
Temper and belief and that differences lost
Difference and were one? It had to be
In the presence of a solitude of the self....”
—Wallace Stevens (1879–1955)