Condensed state helium

Path integral ground state with a fourth-order propagator: application to condensed helium.

Ground state properties of condensed helium are calculated using the path integral ground state (PIGS) method. A fourth-order approximation is used as short (imaginary) time propagator. We compare our results with those obtained with other quantum Monte Carlo (QMC) techniques and different propagators. For this particular application, we find that the fourth-order propagator performs comparably...

Bose-Einstein Condensation Measurements and Superflow in Condensed Helium

We review the formulation and measurement of Bose-Einstein condensation (BEC) in liquid and solid helium. BEC is defined for a Bose gas and subsequently for interacting systems via the one-body density matrix (OBDM) valid for both uniform and non-uniform systems. The connection between the phase coherence created by BEC and superflow is made. Recent measurements show that the condensate fractio...

Determination of BKW Equation of State Parameters via Measurement of the Detonation Velocity in Condensed Explosives

An optical system has been redesigned and used to measure detonation velocity as a function of condensed explosive density for RDX, HMX, PETN. These measurements are then used to determine and fine tune parameters appearing in the BKW (Beker-Kistiakowsky-Wilson) equation of state for gases at extremely high pressures. Steady state form of conservation equations along with the BKW state equation...

Equation of state of dense helium.

Determination of BKW Equation of State Parameters via Measurement of the Detonation Velocity in Condensed Explosives

An optical system has been redesigned and used to measure detonation velocity as a function of condensed explosive density for RDX, HMX, PETN. These measurements are then used to determine and fine tune parameters appearing in the BKW (Beker-Kistiakowsky-Wilson) equation of state for gases at extremely high pressures. Steady state form of conservation equations along with the BKW state equation...