X-ray pulses that are manipulated in highly synchronized combination with IR pulses enable pulse-probe studies -- one input pulses a target system, yielding a fleeting, subpicosecond moment of quite special physical conditions for the other input to probe. In solid state physics and materials science, potential pulse-probe application areas could possibly include temporal dynamics of condensed-matter phase transitions, the ultrafast time-resolved monitoring of structural changes in materials, and heat propagation at submicron dimensions. In biology and chemistry, the capability could be applied to studies of short-range order changes in chemical reactions. In accelerator physics it could be applied to the development of beam diagnostics for next-generation light sources.
Based on the September experiment, Jefferson Lab is responding to a call for proposals aimed at development and application of short-pulse X-ray light sources. The lab's development of high-average-power FELs is an application of the superconducting radio-frequency accelerating technology at the heart of the 6 GeV continuous-wave accelerator that serves nuclear physics. In July, a kilowatt FEL, built mainly with Navy funds, delivered 3.1-micron-wavelength light at 1.72 kilowatts average power. Money has recently been appropriated to start an upgrade intended to deliver 10 kW infrared light and 1 kW ultraviolet light.