Prototype IVA module (PIM)

Summary form only given. As a result of the AWE Pulsed Power Group´s programme to gain expertise in IVA (Inductive Voltage Adder) technology a design has been produced of a prospective module of a large (13 to 15 MV) radiographic IVA machine. The PIM machine has been built at AWE to test a single such module before fixing the design of the full size machine. PIM also provides the basis for the PPG´s continued research programme in this area and hence possible other machines for the future. The PIM machine consists of a single inductive cavity pulsed by a 10 ohm cylindrical water dielectric Blumlein pulse forming line. The Marx generator which charges the Blumlein is based on the Sandia hanging Marx design and uses 32 1.35uF 100kV DC capacitors. The Blumlein switch initially installed has two stages - a Rimfire section and a Trigatron spark gap. A laser triggering configuration utilising two radial switches, designed by Titan PSI, is also to be tested. The inductive cavity incorporates ferromagnetic cores formed from Metglas alloy tape and the fast pulse appears across a perspex (lucite) insulated accelerating gap. The pulse travels along a short vacuum transmission line to a ball/plane e-beam diode test load. Work has been carried out to test the module design. Initially the Marx was characterised into a resistive load to establish its operating regime. The Blumlein PFL and its Rimfire/Trigatron switch were then tested, also using a copper sulphate resistive load. A peak output voltage of 1.7MV was achieved from the PFL. The inductive cavity has been added and is in the process of being tested. A pulse of 1.4MV peak voltage has been successfully applied to it. The latest details of the system´s characterisation will be presented.