title: Electron density characterization by use of a broadband x-ray-compatible wave-front sensor.
abstract: The use of a Hartmann wave-front sensor to accurately measure the line-integrated electron density gradients formed in laser-produced and z-pinch plasma experiments is examined. This wave-front sensor may be used with a soft-x-ray laser as well as with incoherent line emission at multikilovolt x-ray energies. This diagnostic is significantly easier to use than interferometery and moiré deflectometry, both of which have been demonstrated with soft-x-ray lasers. This scheme is experimentally demonstrated in the visible region by use of a Shack-Hartmann wave-front sensor and a liquid-crystal spatial light modulator to simulate a phase profile that could occur when an x-ray probe passes through a plasma. The merits of using a Hartmann sensor include a wide dynamic range, broadband or low-coherence-length light capability, high x-ray efficiency, two-dimensional gradient determination, multiplexing capability, and experimental simplicity. Hartmann sensors could also be utilized for wavelength testing of extreme-ultraviolet lithography components and x-ray phase imaging of biological specimens.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA. baker7@llnl.gov
authors.forename: K L
authors.initials: KL
authors.lastname: Baker
authors.forename: J
authors.initials: J
authors.lastname: Brase
authors.forename: M
authors.initials: M
authors.lastname: Kartz
authors.forename: S S
authors.initials: SS
authors.lastname: Olivier
authors.forename: B
authors.initials: B
authors.lastname: Sawvel
authors.forename: J
authors.initials: J
authors.lastname: Tucker