Options for pulse tailoring on Z for isentropic compression experiments

Summary form only given, as follows. An important option for the ZR upgrade of the Z accelerator is the ability to tailor the load-current pulse shape for optimizing pressure pulses for material compression experiments. Although considerable flexibility is needed, the general shape of the pulse is one that rises quickly to several megamperes, then slowly rises over 100 to 200 ns to 5 to 10 MA, and then quickly rises to nearly 30 MA, with the resulting pulse length being as long as 300 ns. The approach to tailoring is to independently trigger each of the thirty-six lines of the accelerator at different times to stagger pulse arrival times, and to thereby add currents to achieve the desired pulse shape. Further flexibility is offered by operating individual lines in either a long-pulse or short-pulse mode, and by independently varying charge voltages. In order to minimize magnetic nulls in the vacuum transmission lines and to provide a symmetrical current flow, solutions are sought that fit the nine-fold symmetry of each of the four levels of the machine. This problem is being addressed with multi-line circuit-code simulations, and with a spreadsheet model using superposition of the two drive waveforms. In this paper we discuss the results of these simulations and show pulse shapes that can be achieved.