Pulse Forming Network(PFN) is suitable to produce long duration pulse as well as current up to a few KA. Recent work concerned on numerical simulations and a device designed according to the simulation. The simulation includes how to realize the Blumlein structure PFN and the deviations of components which can be neglected. A PFN device based on Blumlein structure is built which can generate a long pulse with 3 μs top flat. Using Blumlein structure and with 12 Ω load, the PFN can produce a pulse with the ou...