Gas lasers with /spl gamma/-radiation pumping as the source of laser energy for research of plasma physics and inertial thermonuclear fusion (ITF)

Abstract

The interaction processes of heavy ions and ionized matter have been investigated extensivly during the last years. The plasmaphysics-group at GSI-Dmstadt has contributed to this research in several fields. At low ion energies (E = 45 keV/u) it was possible to create a heavy-ion heated plasmas with a high current radio-frequency-quadrupol (RFQ) accelerator. The interaction of this low energy beam with extemal generated hydrogen plasmas (ne = 1017 cmm3) showed an increased stopping by a factor of 35 in the plasma compared to a cold gas.In the medium energy range ( 1.5 MeVh < E < 10 Mevh) it was possible to see the effects of the enhanced stopping power of plasma ( 1017 cm-3 < ne < 1019 cm-3) due to the presence of free electrons. Furthermore the effect of the plasma to the ionisation-recombination balance of the heavy ions traversing the plasma was investigated. In the high energy range ( E > 100 MeV/u) the first hydrodynamic motion of heavy ion heated rare gas crystals has been observed recently. The aquisition of a high power Nd:Glass laser (E -100 J, t = 20 ns) makes it now possible to extend the density range of the extemally generated plasmas far beyound ne = 1019 cm-3. An overview of the recent experiments will be given and the impact of laser-produced plasmas in the framework of the progam investigating the interaction of heavy ions with ionized matter will be discussed. 3FP06Experiments on a laser-produced plasma cross-field motion f o r simulation of i n t e r a c t i o n between CRRES releases and geoplasma. Y u . P. Lakharov, J.Wolowski* I n s t . Laser Phys., Russ. Acad. Sci. Novosib., Russia * I n s t . Plasma Phys.Laser Microfusion ,Warsaw, Poland A new c l a s s of simulation experiments with l a s e rproduced plasmas i s discussed with reference t o recent r e s u l t s of CRRES-mission investigations. For b e t t e r understanding of a 1ow-M~ i n t e r a c t i o n processes of ionospheric (VC 36.064 CE o r G-9) and inagnetospheric (G-10) Barium r e l e a s e s [l] with a surrounding magnetized geoplasma, simulation experiments a r e proposed a t high-intensity magnetic f i e l d s (BO 2 10-20 kGs) and with t h e presence of a low-density p a r t i a l l y ionized background. Such experiments have become possible owing t o successful simulations [2] of t h e AMPTE-release and preliminary s t u d i e s of c r o s s -f i e l d plasma motion a t BoSlO kGs, performed a t t h e "KI-1" f a c i l i t y [3] i n Novosibirsk, a s well a s due t o extension of t h e p o s s i b i l i t i e s of high-intensity magnetic f i e l d laser-produced plasma i n t e r a c t i o n experiments i n Warsaw [4]. In p a r t i c u l a r , Hi e hope t o achieve t h e value of t h e main 4 i m i l a r i t y c r i t e r i o n [3] of t h e problem of t h e ion magnetization parameter, C B = RH/RB S 0.3, i n common simulation experiments, which corresponds t o t h e parameters of t h e G-10 r e l e a s e with Ba-ion directed Larmor r a d i u s , RH -10km, and Bacloud stopping radius, R E = (~E O / B~) ' '~* 30 km, a t magnetic f ...