ISSN:0094-243X    

DOI:10.1063/1.39806

出版商:AIP    

年代:1990

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.39812

出版商:AIP    

年代:1990

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.39817

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A review is presented of a number of correlational effects in inner shell processes. Those examples are discussed, where correlations play a considerable or even a decisive role. The photoionization process with its intra‐ and intershell interaction, single and multiple vacancy formation is discussed. The role of correlational effects is described in the probability of creation, energy shift from the corresponding one‐electron value and decay width of single and double vacancy states. Near threshold phenomena with all different kinds of interelectron interaction in the final state are studied. The prominent role of correlations in the process of photon emission in electron‐atom scattering is also demonstrated. The perspectives of the development of this domain of physics are also outlined.

ISSN:0094-243X    

DOI:10.1063/1.39852

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Recent technical advances in relativistic atomic structure calculation will be discussed with particular reference to the GRASP and SWIRLES codes of the speaker and his collaborators. The capabilities of GRASP—2, the modernized version of the Oxford MCDF code, based on finite difference numerical techniques, will be illustrated by applications which could not have been studied with earlier codes. The SWIRLES code, which is based on a novel technique for expressing wave functions as a sum of S—spinor basis functions, is ideally suited to vector—processing computers, and is intended to study relativistic correlation and radiative corrections.Some results obtained with a new relativistic Dirac R‐matrix code will also be presented.

ISSN:0094-243X    

DOI:10.1063/1.39829

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Close coupling expansions are used to describe the initial bound and free final systems Be++e−or B++e−. This approach takes into account interchannel coupling and configuration interaction effects for both the initial and final states. In the beryllium case we consider ejected electron energies with respect to 1s2s2, ranging from 17 eV (corresponding to the upper 1s2s3sthreshold) up to 120 eV. The total photoionization cross section decreases according to the &ngr;−8/3behaviour. The partial photoionization cross sections to the 1s2s2, 1s2s2p, 1s2p2, and 1s2s3sBe+terms are given and compared to the recent experimental data of Krause and Caldwell. At a photon energy of 190 eV, these authors find that the 1s2s2pexcitations amount to about 10.5% of single 1sionization, we also found 10%; their 1s2s3sexcitations is about 19%, we found 20%. This disagreement is due to overestimated C.I. effects in the initial state description. We note that the theoretical ratio I(1s2p2 2S)/I(1s2s2 2S) is close to 0.06 as expected from configuration mixing coefficients. For the Boron case, we note the weak 2p → 3s, 2s → 2pshake up processes compared to the notable 2p → 3peffect. The shake up processes to the B+even parity states due to the inelastic excitation induced by the ejected electron, are correctly estimated. For the B+odd parity states our results appear too high due to overstimated C.I. effects for the B ground state.

ISSN:0094-243X    

DOI:10.1063/1.39847

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The anisotropy of electrons ejected from inner shells by fast electrons is computed in the small momentum transfer limit using the Coulomb‐Born approximation. It is shown that the electron distribution follows that of photoelectrons excited by elliptically polarized radiation. The angular distribution and anisotropy parameter are computed for K‐shells.

ISSN:0094-243X    

DOI:10.1063/1.39820

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

New developments in x‐ray scattering are resulting from the use of synchrotron radiation sources, allowing study of anomalous scattering regimes with high energy resolution and polarized light.Smatrix calculations of elastic scattering are in good agreement away from edges, while dispersion relations can be used to predict edge region scattering if a sufficiently broad and precise photoabsorption data base is available. A new S matrix calculation of inelastic scattering indicates there are substantial regimes in which the p&drarr;⋅A&drarr; as well as the usual’A2’term will have to be taken into account, and many circumstances in which the p&drarr;⋅A&drarr; term will dominate.

ISSN:0094-243X    

DOI:10.1063/1.39853

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A high brilliance synchrotron light source called MAC II is currently being built at MAX‐lab. The ring is optimized for undulator and multipole wiggler radiation in the VUV‐region. It will also act as a complement to the Nordic activity at ESRF. The ring lattice and the planned research activity are discussed.

ISSN:0094-243X    

DOI:10.1063/1.39809

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Japan Atomic Energy Research Institute (JAERI) and the Institute of Physical and Chemical Research (RIKEN) are going to build an 8 GeV synchrotron radiation source in Harima Science Garden City, 100 km west of Osaka. The facility consists of an 8 GeV storage ring of 1436 m circumference with a natural emittance of 6.9 nmrad, an injector linac of 1 GeV and an 8 GeV synchrotron. Construction stars in 1990 and the first beam is foreseen in 1998. At the commissioning time 10 beamlines will be available. The remaining 50 beamlines, 32 on insertion devices and 18 on bending magnets, will be constructed successively.

ISSN:0094-243X    

DOI:10.1063/1.39810

出版商:AIP    

年代:1990

数据来源: AIP