Mechanical Design of a Delay Line for the Astron Linear Accelerator Beam Transport

The Astron concept for Thermonuclear research requires a layer of circulating electrons of sufficient density to confine and heat a plasma. This layer, called the E-layer, is formed by an accelerator injecting 6 Mev electrons at a 4° angle from perpendicular. The accelerator produces a 600 amp pulsed beam of 300 ns duration. A delay line has been built for the purpose of increasing the peak injection current. The 300 ns pulsed beam is split in half by a kicker and the first half is delayed so it can be injected on the opposite side of the trapping solenoid simultaneously with the second half of the beam. Thus two short pulses of 150 ns each are injected into Astron with one pulse traveling through a transport system of five bends and straight sections. (Figure I).