Related papers: Charge, density and electron temperature in a mole…
We have measured the asymptotic expansion velocities of ultra-cold plasmas (UNPs) which evolve from cold, dense, samples of Rydberg rubidium atoms using ion time-of-flight spectroscopy. From this, we have obtained values for the initial…
Double-resonant photoexcitation of nitric oxide in a molecular beam creates a dense ensemble of $50f(2)$ Rydberg states, which evolves to form a plasma of free electrons trapped in the potential well of an NO$^+$ spacecharge. The plasma…
We report the spontaneous formation of a plasma from a gas of cold Rydberg molecules. Double-resonant laser excitation promotes nitric oxide, cooled to 1 K in a seeded supersonic molecular beam, to single Rydberg states extending as deep as…
We study the evolution of ultracold plasmas by measuring the electron temperature. Shortly after plasma formation, competition between heating and cooling mechanisms drives the electron temperature to a value within a narrow range…
We have studied the behavior of cold Rydberg atoms embedded in an ultracold plasma. We demonstrate that even deeply bound Rydberg atoms are completely ionized in such an environment, due to electron collisions. Using a fast pulse extraction…
The double-resonant laser excitation of nitric oxide, cooled to 1 K in a seeded supersonic molecular beam, yields a gas of $\approx10^{12}$ molecules cm$^{-3}$ in a single selected Ryberg state. This population evolves to produce prompt…
Electron evaporation plays an important role in the electron temperature evolution and thus expansion rate in low-density ultracold plasmas. In addition, evaporation is useful as a potential tool for obtaining colder electron temperatures…
We have experimentally demonstrated both heating and cooling of electrons in an ultracold neutral plasma (UNP) by embedding Rydberg atoms into the plasma soon after its creation. We have determined the relationship between the initial…
Ultracold neutral plasmas, formed by photoionizing laser-cooled atoms near the ionization threshold, have electron temperatures in the 1-1000 kelvin range and ion temperatures from tens of millikelvin to a few kelvin. They represent a new…
Recent experiments have demonstrated the spontaneous evolution of a gas of ultracold Rydberg atoms into an expanding ultracold plasma, as well as the reverse process of plasma recombination into highly excited atomic states. Treating the…
Plasma dynamics critically depends on density and temperature, thus well-controlled experimental realizations are essential benchmarks for theoretical models. The formation of an ultracold plasma can be triggered by ionizing a tunable…
The results of a theoretical investigation of an ultracold, neutral plasma composed of equal mass positive and negative charges are reported. In our simulations, the plasma is created by the fast dissociation of a neutral particle. The…
We have used the free expansion of ultracold neutral plasmas as a time-resolved probe of electron temperature. A combination of experimental measurements of the ion expansion velocity and numerical simulations characterize the crossover…
We report the observation of plasma oscillations in an ultracold neutral plasma. With this collective mode we probe the electron density distribution and study the expansion of the plasma as a function of time. For classical plasma…
Penning ionization releases electrons in a state-selected Rydberg gas of nitric oxide entrained in a supersonic molecular beam. Subsequent processes of electron impact avalanche, bifurcation, and quench form a strongly coupled, spatially…
We present the results of direct simulation of the expansionof a two-component ultracold plasmafor various numbers of particles, densities, and electron temperatures. A description of the expansionprocess common to all plasma parameters is…
Ultracold neutral plasmas are formed by photoionizing laser-cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral…
We report the creation of an ultracold neutral plasma by photoionization of laser-cooled xenon atoms. The charge carrier density is as high as 2 x 10^9 cm^-3, and the temperatures of electrons and ions are as low as 100 mK and 10 uK,…
Ultracold plasmas are a promising candidate for the creation of strongly-coupled Coulomb systems. Unfortunately, the values of the coupling parameter Gamma_e actually achieved after photoionization of the neutral atoms remain relatively…
Ultracold neutral plasmas provide a useful system for studying extreme parameter regimes plasma physics in an accessible laboratory setting. The parameter space of plasma physics can be characterized in part by coupling strength and degree…