Findings concerning oscillatory behavior in the synchrotron spectrum of relativistic electrons

Calculations, based on exact relativistic Dirac matrix elements, of the transition rates from arbitrary upper states to each of the five lowest states of an electron in a uniform magnetic field are investigated in detail. In particular, local maxima, whose positions are extremely sensitive to the magnetic field strength, are found in the spectral tail of ultrarelativistic electrons. In addition, local minima are found in the plot of transition rate from initial state $n=5$ to final states nf<5 versus nf for fields H0.70H₀, where H₀=4.414×10¹³ G=quantum-mechanical critical field.