Highly efficient acceleration and collimation of high-density plasma using laser-induced cavity pressure

A novel efficient scheme of acceleration and collimation of dense plasma is proposed and examined. In the proposed scheme, a target placed in a cavity at the entrance of a guiding channel is irradiated by a laser beam introduced into the cavity through a hole and accelerated along the channel by the pressure created and accumulated in the cavity by the hot plasma expanding from the target and the cavity walls. Using 1.315-um, 0.3-ns laser pulse of energy up to 200J and a thin CH target, it was shown that the forward accelerated dense plasma projectile produced from the target can be effectively guided and collimated in the 2-mm cylindrical guiding channel and the energetic efficiency of acceleration in this scheme is an order of magnitude higher than in the case of conventional ablative acceleration.Comment: 4 pages, 6 figure

Increase of the Density, Temperature and Velocity of Plasma Jets driven by a Ring of High Energy Laser Beams

Supersonic plasma outflows driven by multi-beam, high-energy lasers, such as Omega and NIF, have been and will be used as platforms for a variety of laboratory astrophysics experiments. Here we propose a new way of launching high density and high velocity, plasma jets using multiple intense laser beams in a hollow ring formation. We show that such jets provide a more flexible and versatile platform for future laboratory astrophysics experiments. Using high resolution hydrodynamic simulations, we demonstrate that the collimated jets can achieve much higher density, temperature and velocity when multiple laser beams are focused to form a hollow ring pattern at the target, instead of focused onto a single spot. We carried out simulations with different ring radii and studied their effects on the jet properties. Implications for laboratory collisionless shock experiments are discussed.Comment: 5 pages, 4 figures, Accepted to HED

Music and Its Effects on Stress

While stress is a common occurrence within society, some individuals face extreme stressors that can negatively impact their physical and psychological health. College students are a subsect of society that face extreme stress on a daily basis. One of the most common forms of coping among college students is listening to music. The current research examines the effects of music listening on college student’s stress levels. Participants (N= 27) were instructed to complete an impossible mental arithmetic task while under a time limit. Afterwards, participants were given a questionnaire to rate their anxiety levels. During a five-minute recovery period, participants either sat in silence or listened to a piece of music. Then, they were given the same questionnaire to rate their anxiety levels again. A 2x2 mixed ANOVA test concluded that music had no effect on the college student’s stress levels. While these findings do not coincide with current literature, this study can be the starting point in examining how music or music therapy could be used among college students