https://doi.org/10.1051/epjap:2002092
Wavefront measurements in the soft X-ray range
1
Laboratoire de Spectroscopie Atomique et Ionique, Bât. 350, Université Paris-Sud, 91405
Orsay, France
2
Department of Electrical and Computer Engineering, Colorado State University, Fort Collins,
CO 80523-1373, USA
3
Institut d'Électronique et de Microélectronique du Nord, Université des Sciences et
Technologie de Lille, avenue Poincaré, BP 69, 59652 Villeneuve d'Ascq, France
Corresponding author: zeitoun@ensta.fr
Received:
10
December
2001
Revised:
28
May
2002
Accepted:
7
June
2002
Published online:
15
November
2002
In this article we report a new wavefront sensor, developed at the Laboratoire de
Spectroscopie Atomique et Ionique, for a full characterization of soft X-ray beams. The
Shack-Hartmann sensor has a theoretical accuracy in the order of 
at a wavelength
around 13 nm. A cartography of the wave-vectors pointing of laser-pumped soft X-ray laser
has been achieved. It has shown the presence of many ripples probably coming from plasma
instabilities. Capillary discharge soft X-ray laser has been also investigated. For all the
pumping configurations, the wavefront is spherical, divergent with a radius of about 6.5 m at
2.5 m from the plasma end. The best wavefront exhibits an error to a perfect wave of 3λ rms.
Assuming to focus the beam with a f = 50 mm diffraction-limited mirror, a theoretical focal
spot size of 0.5 μm in diameter have been estimated containing 70% of the incident energy. In
that case an intensity of 4 × 1013 W cm−2 should be achieved.
PACS: 42.55.Vc – X- and γ-ray lasers / 41.50.+h – X-ray beams and X-ray optics / 52.58.Lq – Z-pinches, plasma focus and other pinch devices
© EDP Sciences, 2002
