Generation of femtosecond pulses of synchrotron radiation

Femtosecond synchrotron pulses were generated directly from an electron sto rage ring. An ultrashort Laser pulse was used to modulate the energy of ele ctrons within a 100-femtosecond slice of the stored 30-picosecond electron bunch. The energy-modulated electrons were spatially separated from the lon g bunch and used to generate similar to 300-femtosecond synchrotron pulses at a bend-magnet beamline, with a spectral range from infrared to x-ray wav elengths. The same technique can be used to generate similar to 100-femtose cond x-ray pulses of substantially higher flux and brightness with an undul ator, Such synchrotron-based femtosecond x-ray sources offer the possibilit y of applying x-ray techniques on an ultrafast time scale to investigate st ructural dynamics in condensed matter.