The development of hydrodynamic instability (HDI) in laser targets is
studied by means of 2D numerical code ''ATLANT.'' The scaling of HDI d
evelopment for the condition of ''DELFIN-1'' laser setup experiments i
s derived. It is shown that there is the possibility to improve the sh
ell compression condition for the case of long-wave perturbation of la
ser flux (determined by particular target irradiation geometry) by usi
ng the shell with ''relief.''