A Light Pulse Source of a Few Tens of a Picosecond to Nanosecond Width with Cherenkov Radiation

It was experimentally proven that Cherenkov radiation arising from intense electron pulses passing through a dielectric material could be utilized for a light source of short pulse width. A linear accelerator at ISIR, Osaka University, which can produce intense single-bunch electron pulses, was used for a Cherenkov radiation exciter. The spectral distribution and pulse shape of the Cherenkov radiation from an air radiator with these electron pulses were investigated with a fast detection system for this purpose. The spectrum showed a peak at 200 nm and a continuous band of which intensity decreased towards the longer wavelength. The minimum pulse width of the Cherenkov radiation with the single-bunch electrons was about 40 ps, and the light peak power was about 10 kW in the spectral region of 200 to 600 nm.