Pulse radiolysis of liquid water using picosecond electron pulses producedby a table-top terawatt laser system

A laser based electron generator is shown, for the first time, to produce s ufficient charge to conduct time resolved investigations of radiation induc ed chemical events. Electron pulses generated by focussing terawatt laser p ulses into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced by the ionizing electron pulses i s monitored with 0.3 mu s time resolution. Hydrated electron concentrations as high as 22 mu M were generated. The results show that terawatt lasers o ffer both an alternative to linear accelerators and a means to achieve subp icosecond time resolution for pulse radiolysis studies. (C) 2000 American I nstitute of Physics. [S0034-6748(00)01306-X].