L. Willingale,
S. Nagel,
A. Thomas,
C. Bellei,
R. Clarke,
A. Dangor,
R. Heathcote,
M. Kaluza,
C. Kamperidis,
S. Kneip,
K. Krushelnick,
N. Lopes,
S. P. D. Mangles,
W. Nazarov,
P. M. Nilson,
and Z. Najmudin
Characterization of laser-driven proton beams from near-critical density targets using copper activation
J. Plasma Phys., 81 :365810102 (January 2015)
Characterization of laser-driven proton beams from near-critical density targets using copper activation
J. Plasma Phys., 81 :365810102 (January 2015)
Abstract:
Copper activation was used to characterize high-energy proton beam acceleration from near-critical density plasma targets. An enhancement was observed when decreasing the target density, which is indicative for an increased laser-accelerated hot electron density at the rear target-vacuum boundary. This is due to channel formation and collimation of the hot electrons inside the target. Particle-in-cell simulations support the experimental observations and show the correlation between channel depth and longitudinal electric field strength is directly correlated with the proton acceleration.