Single shot terahertz field driven X ray streak camera

A few femtosecond X ray streak camera has been realized using a pump probe scheme that samples the transient response of matter to ionizing soft X ray radiation in the presence of an intense synchronized terahertz field. Borrowing its concept from attosecond metrology, the femtosecond X ray streak camera fills the gap between conventional streak cameras with typical resolutions of hundreds of femtoseconds and streaking techniques operating in the sub femtosecond regime. Its single shot capability permits the duration and time structure of individual X ray pulses to be determined. For several classes of experiments in time resolved spectroscopy, diffraction or imaging envisaged with novel accelerator and laser based short pulse X ray sources this knowledge is essential, but represents a major challenge to X ray metrology. Here we report on the single shot characterization of soft X ray pulses from the free electron laser facility FLAS