Ultrafast Electron Beam Radiography of Self-Generated Magnetic Fields from High Intensity Laser-Solid Interactions
Abstract
Using ~ 30 fs electron bunches generated with laser wakefield acceleration (LWFA) as a probe, the femtosecond temporal evolution of a ~ 4 ×1019 W / cm2 short laser pulse with solid targets has been studied experimentally. Magnetic fields of ~ 100 megagauss were observed travelling outward from the interaction point of the laser with a 10 μm aluminum foil at nearly the speed of light under ideal laser conditions. With degraded contrast, a pre-plasma forms on the front surface, containing the front surface magnetic field to the hole-boring region. This proof-of-principle experiment demonstrates the utility of LWFA electrons as a diagnostic technique for magnetic fields with femtosecond timescale and/or in sufficiently dense plasma. These results are supported by OSIRIS particle-in-cell simulations.
This research was funded by NSF-PHY 0810979.- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- October 2011
- Bibcode:
- 2011APS..DPPGO8002S