Xcimer Energy leverages decades of research on Inertial Fusion Energy (IFE) combined with groundbreaking new laser architecture. Our mission is to deploy fusion power plants to meet global decarbonization goals as fast as possible. Xcimer has assembled a team of leaders in tough tech, fusion science, and manufacturing with a track record of rapid execution. Supported by leading investors, Xcimer is uniquely positioned to deliver limitless, clean, fusion power to combat climate change. Join us in powering a better world with inertial fusion! This is a full-time, onsite role based at our headquarters in Denver, CO. The Head of Diagnostics Physics (Imaging and Spectroscopy) department provides strategic, technical, and organizational leadership for all diagnostic systems supporting practical laser fusion power plants. This role oversees scientific and experimental efforts in optical, X‑ray, and neutron imaging and spectroscopy, including laser beam diagnostics, diagnostics of plasmas, imaging of highly turbulent gas media, backlighting of fusion targets, and advanced fusion‑relevant measurement technologies. This leader will own the execution and continuous improvement of diagnostic capabilities, ensuring that imaging and spectroscopy systems reliably support program objectives. Responsibilities include developing next generation imaging and spectroscopy concepts, validating technologies through experimental work, maturing promising approaches from academia and national laboratories, and ensuring that cutting edge diagnostics translate into accurate models, reliable measurements, and actionable design guidance for future fusion systems. The successful candidate will recruit, mentor, and develop multidisciplinary scientific teams; establish department wide best practices; and drive the maturation of diagnostics from concept to industrializable systems. This role partners closely with laser architects and scientists, target design teams, pulsed power and nuclear groups, manufacturing, operations, and other stakeholders. A key objective is to deeply understand program-defined diagnostic requirements across all subsystems of a fusion power plant: constraints, schedules, tradeoffs, alternative solutions, and derisking experiments, and to build and lead a world-class experimental science organization capable of meeting these needs while continuously evaluating emerging technologies for rapid integration.