Drift rates calculated in FAST range for electrons with energy 5 keV (a), 30 keV (b), and 200 keV (c). On each panel, drift rates for each L value (same values as in Fig. 5) are plotted in a given color (L=2: black, L=5: violet, L=10: blue, L=20: green, L=40: pink). For each L-shell, drift rates are computed for 3 values of the equatorial pitch angle [ϕ_e1/2, ϕ_e1, 1.3 × ϕ_e1], and the curve corresponding to ϕ_e = ϕ_e1 is thicker than the other two. The corresponding value of ϕ_e is indicated next to each curve in the corresponding color. The red and orange lines represent the drift rates measured by FAST (see text). The increased electron energy corresponds to increased drift rates proportional to the electron velocity across the source regions.