The Study On Thermodynamic Property And Disorder-induced Heating In Ultracold Plasmas

The development of the technique of laser cooling and trapping which ionizes laser-cooled atoms near the ionization threshold makes the ultracold neutral (UCN) plasmaspossible. Since the Coulomb interaction between charged particles can’t be neglected, UCNplasmas become the strong coupled system and the classical physical characteristics can’t beused to UCN plasmas, such as phase transitions and spatial correlations between particles.With theemergence ofUCN plasmas,therehasbeena rapidlygrowinginterestin both theoryand experiment in UCN plasmas which provides a well platform for studying the behavior ofplasmas in the strong coupled region and leads plasmas physics to another new field.The degree of spatial correlations between charged particles is quantified by theCoulomb coupling parameters (CCPs) q2a BT, it represents the Coulomb energy of apair of particulates measured in units BT. However, CCPs of ions is i1which shows thestrong coupling of the UCN plasmas, the behavior of these systems is still different from thedense strongly coupled plasmas that main reasons of which can owe to the nonequilibriumstate and short life time of UCN plasmas itself. The stages and time scales in the dynamicsof an UCN plasmas that the evolution can be divided into three phases has been presented bythe Killian et al. The equilibrium state should be understood as quasi-equilibrium state dueto the expansion of plasmas.Although the kinetic theory has been used to study and simulateUCN plasmas previously, a quantityof complicated physical problems of UCN plasmas can’tbe explained by the theory and the method of Monte-Carlo and molecular-dynamics areneeded including molecular dynamics simulations, particle-in-cell approaches and hybridmolecular dynamics model.Actually, we can understand the new physical field by another method. The thesispresents the various thermodynamic properties of UCN plasmas by the method of statisticalthermodynamics including the changing curve of thermal mass as the coupling parameter,the phase transition of ions system and disorder-induced heating. The main contents are asfollows:In the first chapter, some basic concepts and the properties of UCN plasmas will beintroduced, andthedevelopment process andstatus ofUCNplasmas are reportedin summary. In the second chapter, some thermodynamic properties of UCN plasmas will beresearched. We present the changing curve of thermal mass as the coupling parameter andanalyze the reasons of changing. Shukla and Avinash gave a description of phase transitionin UCN plasmas using the theory of equilibrium thermodynamics. To the contrary, we pointout that the phase transition of the UCN plasmas can’t be derived from this method.In the third chapter, we study the disorder-induced heating of UCN plasmas. Thechanging curves of particle density of UCN plasmas as some parameters are presented in thedisorder-induced heating process.In the last chapter, we give out the conclusion and outlook.