Introduction and Overview. The current project concerns fundamental investigations of laser-matter nonlinear interaction at the intensities from moderate to ultrarelativistic values towards the production of antimatter from the ultrastrong laser fields and vice versa: creation of hard ?-ray lasers due to induced annihilation of matter-antimatter, as well as experimental investigations with nanoparticles towards the applications in nano-bio-medicine and “Green Energy” production. The subjects of theoretical investigations in induced processes under laser radiation involve high energy charged particle beams, relativistic solid-plasma-targets, graphene/nanostructures as a matter state with unique electromagnetic nonlinearity. As an intermediate process, to reach generally the high energy region of photons for creation of coherent radiation sources is High Harmonic Generation (HHG) on the atoms-ions-molecules with the large dipole moments, and on the graphene/nanostructures. This process is of importance from the point of view of generation of attosecond pulses too. The proposed investigations will also give us additional information about the high energy radiation-matter state in cosmic objects, specifically in the Galactic Centre and new aspects of macroscopic instability of such systems as powerful sources of particles and ?-ray, as well as more information about the dark matter/energy.
Concerning the problem of implementation of superintense x-ray/?-ray lasers, as a forward mechanism still remains the scheme of Free Electron Lasers (FEL), successfully developed in the past few years in a long wiggler with the lengths in the order of several ten-to hundred meters –LCLS, SPRING 8, and TESLA. In this project we plan to investigate nonlinear and quantum schemes of small setup x-ray/?-ray FELs on relativistic solid-plasma-targets with electron beams of solid densities. In quantum regimes, in contrast to classical one, we can expect significant narrowing of the output radiation spectrum, and in nonlinear schemes - essentially higher gain of FEL at incomparable short lengths, and proposed in this project mechanisms practically may appear more reasonable for x-ray/?-ray FELs due to the smaller set up requirements.
As an efficient mechanism for high energy ?-ray lasers, in this project will also be investigated the other nonlinear mechanism of stimulated annihilation of particle-antiparticle pairs, in particular, at the collective decay of unstable atoms such as positronium ones, Such two-photon beams of ?-ray, produced in the result of collective annihilation from BEC state, are entangled ensemble of photons. Hence, it is planned to investigate thoroughly the problem of ?-ray photons entanglement in two laser beams, which is itself of importance for contemporary quantum physics, interaction between the positronium atoms in the BEC state and ?-ray generation in this condition, as well as generation of ?-ray starting from the initial state-positron captured by atoms, electron-positron annihilation in various positron-binding systems, and in the result of collective annihilation of electron-positron plasma. The last case is especially important for cosmic objects.
One of the alternative ways to reach shortwave region for generation of intense coherent radiation, in the current project it is proposed to use HHG process on the atoms/ions/molecules irradiated by intense pump laser pulses. Concerning this scheme over the past years the significant experimental progress has been achieved on atomic-molecular systems. In particular, to reach the far x-ray region one needs the atoms or ions with a large nuclear charge at which the problem becomes relativistic. To increase the tunneling HHG efficiency we plan to investigate this process and shortwave radiation lasing from the coherent superposition states established in the strong laser field, and the above barrier HHG from a hydrogenlike atom’s superposition states formed by the ground and high excited Rydberg states.
Concerning the nonlinear interaction of coherent radiation with graphene/nanostructures. it is planned to study nonlinear dispersion properties of the particle-hole plasma produced at the multiphoton excitation of Fermi-Dirac-sea in a graphene on h-BN substrate -as a low energy counterpart of ultrarelativistic electron-positron QED plasma, impact of Coulomb forces on the dispersion properties; production and annihilation of particle-hole pairs in the strong magnetic and radiation fields in a graphene on h-BN substrate, in a monolayer/bilayer graphene and spatially separated double-layer graphene formed of two parallel graphene monolayers, Cyclotron Resonance Maser scheme in the mono/bilayer graphene systems in the strong magnetic field when the integer quantum Hall effect takes place, as well as collective annihilation of excitons and magnetoexcitons into photons in graphene bilayers -as a source of intense coherent THz radiation.
The experimental investigation of proposed applications in laser-nanotechnologies concerns the laser synthesis of colloidal nanoparticles of diverse elements and complex materials/nanostructures with the wide spectrum of physicochemical properties -metals, semiconductors, carbon and group III nitrides nanoparticles- and their application in laser-bio-nano-medicine, nanoelectronics, as well as for “Green Energy” production. The main applications of lasers in medicine we propose, specifically relate to laser nanosurgery during the laser photoheating, ablation, soldering and welding procedures; drug delivery by nanocontainers; photothermal and photodynamic influence of laser radiation on normal and cancerous cells; laser fluorescence diagnostics, as well as elaboration of real-time diagnostic techniques, in particular, on the base of the second harmonic generation and multiphoton luminescence in biotissue; development of the clinical laser diagnostics tools; and preparation of medical products with the certain type of nanoparticles.
Expected results and their application. It is expected that the results of the proposed investigations will be important at the construction of small setup devices of coherent radiation in far x-ray/?-ray region with high energy/brightness particle beams. The short wavelength coherent radiation of x-ray/?-ray lasers may offer significant advantages in applications like holograms of microscopic biological structures and in many fields where coherent, short wavelength radiation is required like holography and interferometry on a submicrometer scale etc. The next generation of particle accelerators will likely depend upon novel schemes of reaching the high energies necessary for exploring the future frontiers of physics. Laser acceleration is the main candidate for the solution of this challenging problem, besides it will have significant applications in medicine and Hi-Tech industry. Apart from the scientific significance, if the considering schemes of x-ray/?-ray lasers, or laser accelerators were operational, these devices would reduce greatly the sizes and costs of novel accelerators and projected x-ray FELs, the present size of which is several kilometers and cost is multi-hundred-million-dollar.
Scope of activities. The project involves basic theoretical investigations of nonlinear interaction of moderately strong and superstrong laser radiation with the QED vacuum, high energy charged particle beams and relativistic solid-plasma-films, nanostructures/graphene, for production of matter-antimatter from the ultrastrong laser fields and creation of ?-ray lasers due to the induced annihilation of matter-antimatter and, in general, implementation of high energy sources of new generation; experimental exploration of laser synthesis of colloidal nanoparticles-complex materials-nanostructures – metals, semiconductors, carbon and group III nitrides nanoparticles towards the application in laser-nanomedicine, nanoelectronics, and “Green Energy” production. The Project can be divided into 5 major Tasks: (1) Positronium Atoms and Electron-Positron Plasma for Generation of Intense Coherent ?-ray and Astrophysical Applications; (2) Nonlinear Interaction of High Energy Particle Beams and Relativistic Solid-Plasma-Films with Superintense Laser Radiation for Implementation of x-ray/?-ray FELs; (3) Nonlinear Interaction of Coherent Radiation with Graphene/Nanostructures –THz-nanolasers; (4) Laser Synthesis of Nanoparticles for Nano-biomedicine, Nanooptoelectronics and “Green Energy” Production; (5) Group III Nitrides Nanostructures for Nanooptoelectronics and “Green Energy” Production.
