Ultrahigh intensity Compton scattering focused X-ray source

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:330582

Hartemann, F V ^[1]; Troha, A L; LeSage, G P; Bennett, C V; Kolner, B H; Luhmann, Jr, N C ^[1]

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1. Univ. of California, Davis, CA (United States)

At ultrahigh intensities, where the normalized vector potential associated with the laser wave exceeds unity, the electron axial velocity modulation due to radiation pressure yields nonlinear Compton backscattered spectra. For applications requiring a narrow Doppler upshifted linewidth, such as the future {gamma}-{gamma} collider or focused X-ray generation, this can pose a serious problem. It is shown that temporal laser pulse shaping using spectral filtering at the Fourier plane of a chirped pulse laser amplifier, or similar approaches, can alleviate this problem, and that this technique can be scaled to the required multi-TW range. Compton backscattered spectra are derived in three cases: hyperbolic secant, hybrid pulses (hyperbolic secant transient and flat-top), and square optical pulses similar to those experimentally obtained by Weiner et al. It is found that the optimum laser pulse shapes correspond to square pulses, yielding a high contrast ratio between the main spectral line and the transient lines. The corresponding spectral filter function is also determined, and its practical implementation in a CPA laser is addressed.

• Sponsoring Organization: Department of Defense, Washington, DC (United States); Lawrence Livermore National Lab., CA (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 330582
• Report Number(s): CONF-970559--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
BACKSCATTERING
BEAM SHAPING
COMPTON EFFECT
ELECTROMAGNETIC PULSES
LASER RADIATION
X-RAY LASERS