Partial cross sections of helium satellites at medium photon energies

Technical Report · Tue Apr 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/603578· OSTI ID:603578

Wehlitz, R.; Sellin, I. A. ^[1]; Hemmers, O. ^[2]

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1. Univ. of Tennessee, Knoxville, TN (United States)
2. Univ. of Nevada, Las Vegas, NV (United States); and others

Still of current interest is the important role of single ionization with excitation compared to single ionization alone. The coupling between the electrons and the incoming photon is a single-particle operator. Thus, an excitation in addition to an ionization, leading to a so-called satellite line in a photoelectron spectrum, is entirely due to electron-electron interaction and probes the electron correlation in the ground and final state. Therefore the authors have undertaken the study of the intensity of helium satellites He{sup +}nl (n = 2 - 6) relative to the main photoline (n = 1) as a function of photon energy at photon energies well above threshold up to 900 eV. From these results they could calculate the partial cross-sections of the helium satellites. In order to test the consistency of their satellite-to-1s ratios with published double-to-single photoionization ratios, the authors calculated the double-to-single photoionization ratio from their measured ratios using the theoretical energy-distribution curves of Chang and Poe and Le Rouzo and Dal Cappello which proved to be valid for photon energies below 120 eV. These calculated double-to-single ionization ratios agree fairly well with recent ion measurements. In the lower photon energy range the authors ratios agree better with the ratios of Doerner et al. while for higher photon energies the agreement is better with the values of Levin et al.

• Research Organization: Lawrence Berkeley Lab., CA (United States)
• OSTI ID: 603578
• Report Number(s): LBNL--39981; ON: DE97007345
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CROSS SECTIONS
ELECTRON CORRELATION
EXCITATION
HELIUM
PHOTOIONIZATION
X RADIATION