Terawatt Laser System Research Articles

Generation of x rays for medical imaging by high-power lasers: preliminary results.

To evaluate the use of x-ray imaging performed with a high-power laser system in biologic and medical studies. A compact terawatt laser system based on chirped pulse amplification in titanium-doped sapphire was used. X rays were generated by irradiating a high-atomic-number target (tantalum). When photons with an energy below 10 keV were removed with use of 3 mm of aluminum, the half-value layer in aluminum for the remaining x rays was approximately 10 mm. The x-ray source allowed performance of biologic magnification radiography. Star-pattern tests indicated an equivalent focal spot size of less than 60 microns. Exposures of a single pulse could be obtained. The duration of a single x-ray pulse was estimated to be of the order of picoseconds. With use of subpicosecond laser pulses, x-ray generation can occur with a smaller equivalent focal spot size than with conventional x-ray sources.

Development of an Electron Beam Pumped High Power Kr F Laser

A low impedance electron beam system has been developed to pump a 70 ns, 200 J-class Kr F laser in a face to face configuration. The laser was designed as a power amplifier of a tera-watt picosecond excimer laser system. Two modules of 2 ohm impedance electron beam gun were driven by double parallel plate Blumlein circuits with 500 k V rail-gaps as main switches to pump gain medium uniformly from both sides with the guide magnetic field of 1 k Gauss. The energy deposited in the 42 litter laser gain region was measured by several diagnostics to determine the energy transfer efficiency and the spatial uniformity of energy deposition. The 500 k V rail-gap was triggered by a compact Kr F laser with reduced switching time and jitter of 20 ns and 1.9 ns, respectively. The laser triggering of the rail-gap enabled the exact synchronization of amplifier chain as well as improved operation of this system.

A reliable neodymium glass terawatt laser system

A reliable neodymium glass terawatt laser system