LMU, München
Particle acceleration with high power lasers has been demonstrated by various mechanisms, accelerating electrons to GeV energies. So far, ion energies were stuck in the MeV range unless one could reach intensities ≥ 1024 W/cm2. These parameters are discouraging for advanced accelerator concepts and unacceptable for applications like Ion-driven Fast Ignition (IFI) or hadron therapy. The realization of ultrahigh contrast lasers and free standing nm-thin laser targets however marks a paradigm shift. The combination of these two techniques enables a number of new ion acceleration mechanisms that have been observed in simulations and promise GeV ion energies. Examples are the Break-Out Afterburner (BOA) acceleration and the Phase-Stable Acceleration (PSA) regime, also reported as Radiation Pressure Acceleration (RPA). Here we present the first experimental realization of the BOA acceleration mechanism, achieving 0.5 GeV carbon ions out of a single laser acceleration stage at the Los Alamos Trident laser. Full 3D-PIC simulations at full solid density confirm earlier 1- and 2D results, and are in good agreement with the experimental data. Moreover, having been performed before the experiment, they exhibit extraordinary predictive power. We will discuss the requirements this poses on the drive lasers especially concerning the pulse contrast and report first experimental results in realizing those conditions and how to scale to future lasers.
GSI, Darmstadt
TU Darmstadt, Darmstadt
Funding: Work supported by EURATOM (IFE KiT Program).
The recent development in laser acceleration of protons and ions has stimulated ideas for using this concept as innovative and compact therapy accelerator. While currently achieved parameters do not allow a realistic conceptual study yet we find that our simulation studies on ion collimation and transport, based on output data from the PHELIX experiment, already give a useful guidance. Of particular importance are the chromatic and geometric aberrations of the first collimator as interface between the production target and a conventional accelerator structure. We show that the resulting 6D phase space matches well with the requirements for synchrotron injection.
CEA-IRFU, Gif-sur-Yvette
Funding: This work has been performed in collaboration with FRMII (Munich, Germany) at the MLL tandem accelerator.
For developing new generations of nuclear fuels, in-pile experiments are required. However considering their price and the delay (a few years) between their design and their analysis, each technological solution can not be tested in nuclear fuel reactors. For that purpose, alternative strategies have to be defined, with the view to identify the best candidate to test in-pile. This talk will be focused on the interest of heavy ion irradiation for the selection of low enriched 235U nuclear fuels. To fulfill the requirements of international non-proliferation treaty, high density UMo alloys appear as the only appropriated fuel material especially for the most powerful research reactors cores (material testing reactors, neutron sources). UMo fuel elements usually consist of fissile particles dispersed in an Al matrix. However their in-pile behavior is currently not satisfactory because of the growth of a large interaction layer at UMo/Al interfaces under irradiation. Heavy ion irradiations with 80 MeV 127I ions have been successfully used to simulate the damages caused by the fission products at the UMo/Al interface. The growth of an interaction layer has been reproduced thanks to this out-of-pile methodology. This allows to select remedies (silicon addition to the aluminum matrix, UMo particle coating,…) for the growth of this interaction layer.
IUAC, New Delhi
Conference Closing Remarks.