“…For sustained electron injections lasting up to t ≈ 12−72 hr (Agapitov et al., 2018; Hua, Bortnik, & Ma, 2022; Mourenas, Artemyev, et al., 2022; Turner et al., 2015), Equation gives E max ≈ 0.8–2 MeV. The weak variation of E max with parameters in Equation , and the much smaller electron flux above ∼1.5 MeV during intense injections (Hua, Bortnik, & Ma, 2022; Mourenas, Artemyev, et al., 2022; Olifer et al., 2022), lend credence to this first‐order estimate.…”