Energy Increase in Multi-MeV Ion Acceleration in the Interaction of a Short Pulse Laser with a Cluster-Gas Target

Abstract

An approach for accelerating ions, with the use of a cluster-gas target and an ultrashort pulse laser of 150-mJ energy and 40-fs duration, is presented. Ions with energy 10-20 MeV per nucleon having a small divergence (full angle) of 3.4 degrees are generated in the forward direction, corresponding to approximately tenfold increase in the ion energies compared to previous experiments using solid targets. It is inferred from a particle-in-cell simulation that the high energy ions are generated at the rear side of the target due to the formation of a strong dipole vortex structure in subcritical density plasmas.

Protons Acceleration by CO2 Laser Pulses and Perspectives for Medical Applications

“…As a consequence, the protons are efficiently accelerated and nicely collimated ; Nakamura, Bulanov, Esirkepov & Kando (2010); Naumova & Bulanov (2002); Yogo (2008)]. Experimental results with near critical targets confirmed the theoretical and simulation results on the enhancement of maximum energy and reduction of angular spread with respect to the TNSA acceleration mechanism [Fukuda & Bulanov (2009)]. …”

Ultra-Intense, High Spatio-Temporal Quality Petawatt-Class Laser System and Applications

“…Solid state nuclear track detectors such as CR-39 detectors have been so far extensively used to detect laser-accelerated ions [18]. It is, however, impossible to detect ions with energies higher than the detection threshold limit of the CR-39, where the detection threshold limit is defined as the particle energy where the stopping power in the detector becomes smaller than the sensitivity of the detector.…”

“…Currently, the development of high power femtosecond laser system having a 200 PW level is being pursued through European Extreme Light Infrastructure (ELI) project [13]. This progress in high-field science gives rise to the birth of new applications and breakthroughs which include relativistic particle acceleration [14][15][16][17][18][19][20], bright X-ray source generation [21][22][23][24][25][26][27], and nuclear activation [28,29].…”

Laser-Driven Proton Acceleration Research and Development

“…In particular, in the TNSA regime higher ion energy is expected from thinner target in the ideal case, but in real experiments the rear surface of very thin targets is perturbed due to the preplasma formation, so there is an optimum target thickness (Kaluza et al 2004). The ASE can even turn the originally soliddensity target into a near-critical density plasma cloud (Matsukado et al 2003;Yogo et al 2008), so the acceleration mechanism changes, and the ions are accelerated by a long-living charge separation electric field, sustained by a quasistatic magnetic field of dipole vortex (Bulanov et al 2005;Fukuda et al 2009). In order to understand the influence of the laser contrast in the described experiments, we performed the laser contrast diagnostics based on the target reflectivity measurement.…”