The classical free electron photon emission and absorption.

1. Jan 7, 2014

goodphy

The definition of the Gaunt factor.

Hello.

I'm wondering about the Gaunt factor.

I'm currently interesting in the spectroscopy in which the Gaunt factor is the correction factor to the classical cross section associated to the photon with electron thus the corrected formula is the identical to the formula derived in quantum-mechanical way.

For photon-free electron interaction, the several papers define the Gaunt factor as σ$_{q,a}$/σ$_{c,a}$ where q and c stand for 'quantum' and 'classical' while a means absorption of the photon by electron (inverse bremsstrahlung).

It seems that this definition is exact for photon absorption by electron.

My question is whether the Gaunt factor defined in this way is also applicable to the photon emission from free electron (bremsstrahlung) or not.