Electrostatic shock acceleration of ions in near-critical-density plasma driven by a femtosecond petawatt laser.

With the recent advances in ultrahigh intensity lasers, exotic astrophysical phenomena can be investigated in laboratory environments. Collisionless shock in a plasma, prevalent in astrophysical events, is produced when a strong electric or electromagnetic force induces a shock structure in a time scale shorter than the collision time of charged particles. A near-critical-density (NCD) plasma, generated with an intense femtosecond laser, can be utilized to excite a collisionless shock due to its efficient and rapid energy absorption.

Ground state in E ⊗ e Jahn-Teller and Renner-Teller systems: Account of nonadiabaticity.

The ground and lower excited states of an E⊗e Jahn-Teller system with linear and quadratic vibronic coupling are considered, taking nonadiabaticity into account. Our calculations confirm a common opinion that in the case of a weak quadratic coupling, the ground state is doubly degenerate and the first excited state is nondegenerate for any linear coupling. However, with increasing quadratic coupling for weak linear coupling, the nondegenerate state becomes the ground state.

Time-dependent Jahn-Teller problem: phonon-induced relaxation through conical intersection.

A theoretical study of time-dependent dynamical Jahn-Teller effect in an impurity center in a solid is presented. We are considering the relaxation of excited states in the E⊗e-problem through the conical intersection of the potential energy. A strict quantum-mechanical treatment of vibronic interactions with both the main Jahn-Teller active vibration and the nontotally symmetric phonons causing the energy loss is given.

Effective generation of the spread-out-Bragg peak from the laser accelerated proton beams using a carbon-proton mixed target.

Conventional laser accelerated proton beam has broad energy spectra. It is not suitable for clinical use directly, so it is necessary for employing energy selection system. However, in the conventional laser accelerated proton system, the intensity of the proton beams in the low energy regime is higher than that in the high energy regime.

Transition of proton energy scaling using an ultrathin target irradiated by linearly polarized femtosecond laser pulses.

Particle acceleration using ultraintense, ultrashort laser pulses is one of the most attractive topics in relativistic laser-plasma research. We report proton and/or ion acceleration in the intensity range of 5×10(19) to 3.3×10(20) W/cm2 by irradiating linearly polarized, 30-fs laser pulses on 10-to 100-nm-thick polymer targets.