S. Witkowski

Status of the Asterix IV iodine laser

After a description of the design and layout of the 2 kJ/5 TW single beam Asterix IV iodine laser the steps necessary for obtaining a laser beam intensity profile as homogeneous as possible are reported. These steps are: providing a homogeneous inversion density profile in the amplifiers by an appropriate flashlamp-reflector geometry and by compensating the edge enhancement caused by the image relaying system by suitable soft apertures. The paper concludes with a description of the results obtained by the laser system with the end-amplifier not in operation. The full system will become operational at the end of 1990.

Layout and performance of the Asterix IV iodine laser at Max-Planck-institut fuer Quantenoptik, Garching

The single beam Asterix IV high power iodine laser ((lambda) equals 1.32 micrometers ) provides at present a maximum output energy of 2.1 kJ at a pulse length of 5 ns and an output power of 4 TW at 0.3 ns pulses. This laser is designed to deliver pulses with lengths ranging from 0.2 to 5 ns with a maximum power of 5 TW and an energy of up to 2 kJ. Asterix IV has been developed on the 10 years experience with the 1 TW Asterix III laser and with the support of a 1D and a 3D pulse propagation code. Special emphasis has been put on achieving a high overall system efficiency and laser beam intensity profile as homogeneous as possible. In this paper the measures for optimizing the laser performance and the results obtained will be described.

Asterix IV iodine laser at MPQ Garching

The Asterix IV high power iodine laser is designed to deliver in a single beam output pulses with lengths ranges from 0.1 to 4 ns with a maximum power of 5 TW and an energy of up to 2 kJ. This laser has now achieved its projected output energy of 2.0 kJ and an output power of 4 TW. The Asterix laser has been developed on the basis of 10 years of experience with the 1 TW Asterix III laser and with the support of a 1D and a 3D pulse propagation code. Special emphasis has been put on obtaining an optimal overall efficiency of the laser system and a laser beam intensity profile as homogeneous as possible.

X rays from laser-produced plasma

Examples of experiments using x rays from laser produced plasmas are given.

Laser−plasma research at MPQ

The ASTERIX iodine laser delivers after frequency tripling to λ = 0.44-μm laser pulses with energies up to 500 J at a pulse duration of 300 ps for target experiments. Experimental investigations of radiative transfer in low- and high-Z materials are reported.

Status report of the Asterix IV high-power iodine laser

The Asterix IV high power iodine laser was projected to deliver output pulse energies of up to 2 kJ at pulse lengths tp >= 1 ns in one beam. Using a mode-locked or a long-pulse oscillator the pulse duration can be adjusted in the range between 0.1 and 3 ns. In addition, in the fundamental wavelength at 1315 nm the laser can be operated at either the second or third harmonic at (lambda) equals 658 nm and (lambda) equals 438 nm, respectively. Up to now a maximum output energy of 1.3 kJ could be extracted which was -- at tp equals 0.4 ns -- limited only by the damage threshold of optical components. Emphasis has been put on improving the laser performance; e.g., the energy density of the top hat beam profile shows a modulation as small as +/- 6% and the output pulse energy can be kept stable within +/- 4% during a period of several months. Since 1988 the laser has been used for 3000 target shots and it has proved a reliable tool.