Extreme ultraviolet

Alternatively, the free electrons and ions may be generated temporarily and instantaneously by the intense electric field of a very-high-harmonic laser beam.

The electrons accelerate as they return to the parent ion, releasing higher energy photons at diminished intensities, which may be in the EUV range.

Continuously tunable narrowband EUV light can be generated by four wave mixing in gas cells of krypton and hydrogen to wavelengths as low as 110 nm.

[4] As the name implies, an exciton is an excited state; only when it disappears as the electron and hole recombine, can stable chemical reaction products form.

[5] Certain wavelengths of EUV vary by as much as a factor of 50 between solar minima and maxima, [6] which may contribute to stratospheric warming and ozone production.

EUV damage has already been documented in the CCD radiation aging of the Extreme UV Imaging Telescope (EIT).

A recent study at the University of Wisconsin Synchrotron indicated that wavelengths below 200 nm are capable of measurable surface charging.

Studies using EUV femtosecond pulses at the Free Electron Laser in Hamburg (FLASH) indicated thermal melting-induced damage thresholds below 100 mJ/cm2.

[12] An earlier study[13] showed that electrons produced by the 'soft' ionizing radiation could still penetrate ~100 nm below the surface, resulting in heating.