, "Quasi-monoenergetic and tunable X-rays from a laser-driven Compton light source" (2013). Donald Umstadter Publications. 92.

Ghebregziabher, I.; Maharjan, C.; Liu, Cheng; Golovin, Grigory V.; Banerjee, Sudeep; Zhang, J.; Cunningham, N.; Moorti, A.; Clarke, S.; and Pozzi, Sara, "MeV-Energy X Rays from Inverse Compton Scattering with Laser-Wakefield Accelerated Electrons" (2013). Donald Umstadter Publications. 87.

Based on single particle tracking in the framework of classical Thomson scattering with incoherent superposition, we developed a fully relativistic, three dimensional numerical code that calculates and quantifies the characteristics of emitted radiation when a relativistic electron beam collides head-on with a focused counter-propagating intense laser field. The developed code has been benchmarked against analytical expressions, based on the plane wave approximation to the laser field, derived in (1). For sufficiently long duration laser pulses, we find that the scattered radiation spectrum is broadened due to interferences arising from the pulsed nature of the laser.We show that by appropriately chirping the scattering laser pulse, the spectral broadening could be minimized.

ORION laser target diagnostics Rev. Sci. Instrum. 83, 10D732 (2012) Target normal sheath acceleration sheath fields for arbitrary electron energy distribution Phys. Plasmas 19, 083115 (2012) Saturation gain-length product during short-wavelength plasma lasing Appl. Phys. Lett. 101, 081105 (2012) Laser induced avalanche ionization in gases or gas mixtures with resonantly enhanced multiphoton ionization or femtosecond laser pulse pre-ionization Phys. Plasmas 19, 083508 (2012) Additional information on Phys. PlasmasIn this paper, we present results on a scalable high-energy electron source based on laser wakefield acceleration. The electron accelerator using 30-80 TW, 30 fs laser pulses, operates in the blowout regime, and produces high-quality, quasi-monoenergetic electron beams in the range 100-800 MeV. These beams have angular divergence of 1-4 mrad, and 5%-25% energy spread, with a resulting brightness 10 11 electrons mm À2 MeV À1 mrad À2 . The beam parameters can be tuned by varying the laser and plasma conditions. The use of a high-quality laser pulse and appropriate target conditions enables optimization of beam quality, concentrating a significant fraction of the accelerated charge into the quasi-monoenergetic component. V C 2012 American Institute of Physics.

The photoionization of methane is reported for intensities up to 10(19) W/cm2 with linear and circular polarized light. While fragmental ions (e.g., CH3+, CH+, C+, C2+) created from 10(14) W/cm2 to 10(15) W/cm2 are formed by Coulomb explosion, ionization to form C3+ and C4+ involves Coulomb explosion and tunneling ionization. In ultrastrong fields, removal of a carbon K-shell electron from methane proceeds via tunneling and rescattering ionization, without the influence of molecular channels. Photoelectrons from methane at 10(19) W/cm2 extend up to kinetic energies of 0.6 MeV.