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The smallest nuclei that have to date been found to be capable of alpha emission are beryllium-8 and tellurium-104, not counting beta-delayed alpha emission of some lighter elements. The alpha decay sometimes leaves the parent nucleus in an excited state; the emission of a gamma ray then removes the excess energy.
The following are among the principal radioactive materials known to emit alpha particles. 209 Bi , 211 Bi , 212 Bi , 213 Bi 210 Po , 211 Po , 212 Po , 214 Po , 215 Po , 216 Po , 218 Po
Similarly to Lyman-alpha, the K-alpha emission is composed of two spectral lines, K-alpha 1 (Kα 1) and K-alpha 2 (Kα 2). [6] The K-alpha 1 emission is slightly higher in energy (and, thus, has a lower wavelength) than the K-alpha 2 emission. For all elements, the ratio of the intensities of K-alpha 1 and K-alpha 2 is very close to 2:1. [7]
The transitions are named sequentially by Greek letters: from n = 2 to n = 1 is called Lyman-alpha, 3 to 1 is Lyman-beta, 4 to 1 is Lyman-gamma, and so on. The series is named after its discoverer, Theodore Lyman. The greater the difference in the principal quantum numbers, the higher the energy of the electromagnetic emission.
Alpha spectrometry (also known as alpha(-particle) spectroscopy) is the quantitative study of the energy of alpha particles emitted by a radioactive nuclide that is an alpha emitter. As emitted alpha particles are mono-energetic (i.e. not emitted with a spectrum of energies, such as beta decay ) with energies often distinct to the decay they ...
The decay scheme of a radioactive substance is a graphical presentation of all the transitions occurring in a decay, and of their relationships. Examples are shown below. It is useful to think of the decay scheme as placed in a coordinate system, where the vertical axis is energy, increasing from bottom to top, and the horizontal axis is the proton number, increasing from left to right.
Lyman-alpha, typically denoted by Ly-α, is a spectral line of hydrogen (or, more generally, of any one-electron atom) in the Lyman series. It is emitted when the atomic electron transitions from an n = 2 orbital to the ground state ( n = 1), where n is the principal quantum number .
In atomic, molecular, and optical physics, the Einstein coefficients are quantities describing the probability of absorption or emission of a photon by an atom or molecule. [1] The Einstein A coefficients are related to the rate of spontaneous emission of light, and the Einstein B coefficients are related to the absorption and stimulated ...