Ultrahigh-brightness KrF laser system for fast ignition studies

The main requirements for a fast igniter laser beam are reviewed and shown to favour short wavelength and ultrahigh brightness. These requirements are met by the new KrF laser system at Rutherford Appleton Laboratory called T ITANIA. TITANIA uses two schemes to enhance the laser beam brightness. The first is chirped pulse amplification which is used to enhance brightness by compressing the pulse into the femtosecond region. In this mode TITANIA pr oduces in the region of 250 mJ on target in 700 fs. The second mode of oper ation uses a Raman technique for beam combining and beam clean-up which is designed to give a single beam of 80 joules on target in a pulselength of 6 0 ps. In this scheme the KrF wavelength is Raman shifted to 268 nm. The Ram an amplifiers will use gaseous rather than solid windows and experiments wh ich demonstrate their feasibility will be described. A concept for a reacto r scale fast igniter beam using the Raman technique will be discussed. (C) 1999 Elsevier Science S.A. All rights reserved.