OPTICAL MANIPULATION OF COLD COLLISIONS AND POSSIBLE IMPLICATION IN THE THERMODYNAMIC OF THE GAS SAMPLE

In this paper we present the subject covered in the talk given at the 1996 Laser Physics Conference (Moscow). We use photoassociative ioniza tion in a sample of cold atoms as a prototype to demonstrate the possi bility of manipulating cold collision channels through the access of r epulsive states. In the presence of a blue tuned photon, cold atoms ar e prevented to approach each other creating the equivalent of a hard s phere of controlled size. This effect could have profound influence as the values of the heat capacity of a Bose gas in the vicinity of the critical temperature. This idea deserves to be investigated in the con text of the new achievement in this field.