Jean Galy

Fission of actinides with tabletop lasers

We report the first laser induced fission of actinide nuclei with high intensity tabletop lasers. The results are discussed in the context of laser plasma diagnostics and nuclear waste handling.

Bremsstrahlung production with high-intensity laser matter interactions and applications

In the last decade an evolution of experimental relativistic laser-plasma physics has led to highly sophisticated lasers, which are now able to generate ultra short pulses and can be focused to intensities in excess of 1021 W cm−2, with more than 500 J on target. In the intense electric field of the laser focus, plasma with temperatures greater than 10 billion degrees can be generated. The laser interactions with solid or gas targets can generate collimated beams of highly energetic electrons and ions. Experiments utilizing high-intensity laser systems turn out to be an interesting and versatile source for radiation, high-energy particles and nuclear reactions, without recourse to large-scale facilities such as nuclear reactors or particle accelerators. The possibility of accelerating electrons to energies over 200 MeV in such early experiments led to the utilization of high-energy bremsstrahlung radiation in order to investigate laser-induced gamma reactions. Many experiments of this type have been reported in several laboratories worldwide. However, to our knowledge, no dedicated investigations have been reported with respect to the characterization of the generated bremsstrahlung in such experiments. As it is not experimentally feasible to measure directly a bremsstrahlung spectrum, we report in the present paper on a dedicated series of calculations on the generated bremsstrahlung distributions from two experimental electron spectra measured using the giant pulse VULCAN laser and a gas jet target. Potential applications are also investigated.

Laser-generated nanosecond pulsed neutron sources: scaling from VULCAN to table-top

Neutron production capabilities of table-top laser accelerated protons based on data from a high-energy single-shot large laser are addressed. Recently, McKenna et al (2005 Phys. Rev. Lett. 94 084801) have analysed the energy spectrum for a beam of protons accelerated on the VULCAN laser. In this paper, we present a new analysis of the same experiment which demonstrates, for the first time, production levels in excess of 109 neutrons per laser shot within a nanosecond pulse through (p,xn) reactions on lead targets. We have used this natPb(p,xn) conversion analysis approach to make predictions on the neutron production capabilities of table-top laser systems. Neutron spectra for current state-of-the-art table-top lasers have been calculated, and we have estimated that current systems are capable of producing 106 neutrons per second in nanosecond pulses. Furthermore, we have found that nanosecond neutron pulses at a rate of 5 ? 109 neutrons per second are possible with the next generation of table-top lasers currently under construction.

Electron and Proton Acceleration from Solid Targets by High-intensity Table-top Lasers

Electron and proton beams were investigated using a compact laser with intensities up to 2times1019 W/cm2 irradiating thin targets. For the direction of the electron beam theory and experiment disagree