Probing dense plasmas for HEDS and ICF*

This paper is a retrospective of almost four decades of conceptualization and development of active x-ray probing of dense plasmas, involving multiple teams. In hindsight it was a surprisingly nonlinear and nonsystematic progression, with cycles of key epiphanies followed by multi-step technique optimization, spanning years. Each new idea or endeavor, whether or not realized / successful, spawned the next, and not necessarily in order of difficulty. The journey can be summarized by adapting/paraphrasing what Edward Teller said about NIF, that we develop new capabilities precisely because we don't know what those capabilities will enable.