M. Brewczyk et K. Rzazewski, Interaction of a multi-electron atom with intense radiation in the VUV range: beyond the conventional model for high harmonic generation, J PHYS B, 34(9), 2001, pp. L289-L296
Citations number
27
Categorie Soggetti
Physics
Journal title
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
We investigate the response of a multi-electron atom to an intense radiatio
n at photon energies up to 40 eV. Such sources of radiation are just being
tested, based on VUV free-electron laser systems. We observe the generation
of high harmonics well beyond the cut-off predicted by the conventional th
ree-step model (known also as a simple man's model), successfully applied a
t optical wavelengths. The high harmonics (photon energies in keV range) ar
e produced in the vicinity of the nucleus, i.e., by the core electrons whic
h start to vibrate at higher laser frequencies. We predict the appearance o
f even multiples of the driving frequency in the harmonic spectrum just bef
ore the electrons in the consecutive, more tightly bound shell become activ
e.