Analytical Thomson backscattering spectra and new scaling laws in laser and magnetic fields

The analytical asymptotic expression of Thomson backscattering spectra in arbitrarily polarized laser and uniform magnetic fields is given. It is used to theoretically analyze the spectra structures and properties. The results of asymptotic expression and numerical calculations show good agreement in the large harmonic-order region. The scaling laws about laser intensity and electron initial axial momentum are obtained. Furthermore, the optimal harmonic order corresponding to the maximum radiation intensity can be found, then new scaling laws about this optimal harmonic order with laser intensity and resonance parameter are revealed. Copyright (C) EPLA, 2019.