Electron density characterization by use of a broadband x-ray-compatible wave-front sensor

• Published in: Optics letters 2003-02, Vol.28 (3), p.149-151
• Main Authors: Baker, K L, Brase, J, Kartz, M, Olivier, S S, Sawvel, B, Tucker, J
• Format: Article
• Language: English
• ISSN: 0146-9592; 1539-4794
• DOI: 10.1364/OL.28.000149

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.