Laser particle acceleration technologies : probe laser beam diagnostics of extended plasmas

As plasma-based particle acceleration techniques are becoming intensely developed, the diagnostic tools for the study of the generation and properties of plasmas are increasingly important. We present results on the investigation of probe laser beam diagnostics for the measurement of the plasma density in extended spatial regions. Such extended plasmas are used in particle driven plasma wakefield acceleration experiments for the acceleration of electron/positron bunches to as high as TeV energies in the foreseeable future

Creation of Coherent Superposition States in Inhomogeneously Broadened Media with Relaxation

We propose and analyze a scheme for "on demand" creation of coherent superposition of meta-stable states in a tripod-structured atom using frequency-chirped laser pulses. Negligible excitation of the atoms during the creation of the superposition states is a priority in our consideration. The underlying physics of the scheme is explained using the formalism of adiabatic states. By numerically solving master equation for the density matrix operator, we analyze the influence of the spontaneous decay and transverse relaxation on the efficiency of the creation of superposition states. We show that the proposed scheme is robust against small-to-medium variations of the parameters of the laser pulses. We provide a detailed analysis of the effect of the inhomogeneous (Doppler-) broadening on the efficiency of the coherence creation and show that the proposed scheme may be equally efficient in both homogeneously and Doppler-broadened media

Pre-excitation studies for rubidium-plasma generation

a b s t r a c t The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (PWFA) project is the generation of highly uniform plasma from Rubidium vapor. A scientifically straightforward, yet highly challenging way to achieve full ionization is to use high power laser which can assure the barrier suppression ionization (BSI) along the 10 m long active region. The Wigner-team in Budapest is investigating an alternative way of uniform plasma generation. The proposed Resonance Enhanced Multi-Photon Ionization (REMPI) scheme can be probably realized by much less laser power. In the following we plan to investigate the resonant pre-excitations of the Rb atoms, both theoretically and experimentally. In the following our theoretical framework is presented together with the status report about the preparatory work of the planned experiment