The relativistic problem of motion of a classical electrical point charge that has been placed between the plates of a charged capacitor and then released from rest is well-posed in Bopp-Land\'e-Thomas-Podolsky (BLTP) electrodynamics. That theory introduces a single new parameter, Bopp's $\varkappa$, a reciprocal length. The present article concerns the small-$\varkappa$ regime. Radiation-reaction effects on the motion are shown to appear at order $\varkappa^3$. It is found that in the initial phase the motion is accurately accounted for by test particle theory, with the inertia determined by the bare mass of the particle. Subsequently, radiation-reaction effects cause substantial deviations from the test particle motion.
Categories: physics.class-ph gr-qc math-ph math.MP