Charge-coupled-device detection of soft x rays for grazing-incidence spectrometers.

We describe calculations of the sensitivity of CCD's to soft x rays incident at grazing angles. Soft-x-ray spectrometers based on a Rowland-circle geometry have a focal plane and hence detector surface at grazing incidence to the soft × rays. We model the penetration of the grazing-incidence soft × rays to the sensitive region of the CCD and predict the charge-collection efficiency as a function of wavelength. The results show significant advantages over microchannel plate intensified detection.

Plasma dynamics in capillary discharge soft x-ray lasers.

The dynamics and stability of collapsing gas columns, generated by a fast capillary discharge setup, are studied for obtaining soft x-ray amplification in highly ionized ions. Electron temperature and density measurements at the peak of the compression stage are used for tuning the discharge parameters. Once the needed conditions were achieved, strong amplification of the 3s-3p transition in Ne-like Ar ions at 469 A is observed. A gain coefficient of >0.75 cm(-1) and a beam divergence of <5 mrad are measured along plasma columns of <150 microm diameter and up to 165 mm length.