A new high‐voltage pulse‐forming line, the radial isolated Blumlein (RIB), is described. The new configuration produces an output voltage pulse into a matched load equal to the charge voltage on the line (as in a conventional Blumlein circuit); however, the prepulse level is negligible and both sides of the load remain at electrostatic ground potential. The RIB is rapidly charged to allow 24 oil dielectric spark channels to close within ∼2 ns. With this number of channels, 94% of the theoretical peak voltage is achieved even though the pulse duration is only 15 ns. Using a foilless diode load, the device has been used to generate 4‐MeV, 100‐kA electron beam pulses.