Characterization of High-Intensity Laser Propagation in the Relativistic Transparent Regime through Measurements of Energetic Proton Beams
- Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)
- Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon, OX11 0QX (United Kingdom)
- GoLP, Instituto Superior Tecnico, Lisbon (Portugal)
- University of St. Andrews, Fife, KY16 9ST (United Kingdom)
Experiments were performed to investigate the propagation of a high intensity (I{approx}10{sup 21} W cm{sup -2}) laser in foam targets with densities ranging from 0.9n{sub c} to 30n{sub c}. Proton acceleration was used to diagnose the interaction. An improvement in proton beam energy and efficiency is observed for the lowest density foam (n{sub e}=0.9n{sub c}), compared to higher density foams. Simulations show that the laser beam penetrates deeper into the target due to its relativistic propagation and results in greater collimation of the ensuing hot electrons. This results in the rear surface accelerating electric field being larger, increasing the efficiency of the acceleration. Enhanced collimation of the ions is seen to be due to the self-generated azimuthal magnetic and electric fields at the rear of the target.
- OSTI ID:
- 21180322
- Journal Information:
- Physical Review Letters, Vol. 102, Issue 12; Other Information: DOI: 10.1103/PhysRevLett.102.125002; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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