One form of this phenomenon occurs when electrons absorb and reemit X-rays with an energy close to that of their  nuclear binding energy. The parameter associated with another form of this phenomenon is equal to the second derivative  of the phase constant with respect to angular frequency. That parameter takes the opposite sign as the derivative of the  group velocity wit
One form of this phenomenon occurs when electrons absorb and reemit X-rays with an energy close to that of their  nuclear binding energy. The parameter associated with another form of this phenomenon is equal to the second derivative  of the phase constant with respect to angular frequency. That parameter takes the opposite sign as the derivative of the  group velocity with respect to angular frequency. This phenomenon broadens pulses in space and time. It can be modeled  empirically using the (*) Sellmeier equation. One measure of this phenomenon puts glasses into categories of crowns, at high numbers, and flints, at low numbers, and is the V, or Abbe, number. This phenomenon is the source of chromatic aberrations. For 10 points, name this phenomenon in which a material's index of refraction is dependent on the wavelength of incident light,  which allows prisms to separate the constituents of white light.
One form of this phenomenon occurs when electrons absorb and reemit X-rays with an energy close to that of their  nuclear binding energy.