Alpha constant

In pilitron physics, the alpha constant (denoted ) is a constant that when multiplied by the diameter of an orbit, gives the fraction of the speed of light that an electron would travel at around that orbit. It is defined as:


 * $$\alpha = \frac{X\pi}{c}$$

where:
 * X = rotation speed of an electron
 *  = 3.14...
 * c = the speed of light

The alpha constant may be used to calculate the speed of an electron in an orbit of radius r:


 * $$v = 2rc\alpha \,\!$$