Eigenchannel treatment of R-matrix theory

Li, Jiaming; Ky, L. Vo; Qu, Yi-Zhi; Yan, Jun; Zhang, Peihong; Zhou, H. L.; Faucher, P.

doi:10.1103/physreva.55.3239

Cited by 28 publications

(29 citation statements)

References 25 publications

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“…From the picture of electron-ion collision processes, the N-electron-ion core target states and the excited electron with the appropriate angular momentum couplings form channels for the N+1-electron excited complex with a specific total angular momentum. Based on the R-matrix theory [11][12][13][14]16], the logarithmic derivative boundary matrix R(E) can be obtained by solving the N +1electron problem variationally within the R-matrix box, i.e., the reaction zone. With the R(E) matrix, the reaction matrix K(E) can be calculated with the following standing-wave expressions on the boundary of the reaction zone (i.e., r = r 0 ):…”

Section: A the Calculation Of Short-range Scattering Matricesmentioning

confidence: 99%

“…Our scenario is a combination of indispensable theoretical * xgao@csrc.ac.cn computations and benchmark experimental measurements. More specifically, we have modified both Breit-Pauli [11,12] and Dirac R-matrix codes [13], referred to as R-eigen and R-R-eigen [14], to directly calculate scattering matrices in the whole energy regions of interest, i.e., either discrete energy region or continuum energy region, on equal footing. Using these codes, the scattering matrices in the discrete energy region can be calculated with enough accuracy which can be determined readily by comparisons with precise spectroscopic measurements [15] based on multichannel quantum defect theory (MQDT) [9,10,[16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

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Precision spectroscopy and electron-ion scattering

Gao

2014

Phys. Rev. A

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Scientific research fields for future source of energy such as inertial confinement fusion research and astrophysics studies, especially with satellite observatories, advance into stages of precision physics. The relevant atomic data are not only enormous but also of accuracy according to requirements, especially for both energy levels and the collision data. We propose a scenario to provide such abundant atomic data with enough accuracy based on analytical continuation properties of the scattering matrices, which is a combination of indispensable theoretical computations and benchmark experimental measurements. Using our modified R-matrix method we can directly calculate the scattering matrices in the whole energy regions, from which we can obtain all energy levels and the related scattering cross sections with accuracies comparable with spectroscopic precision. The e+Kr + system is used as an illustrative example; the degrees of accuracies of scattering matrices of each partial wave are calculated within about 6%, which should be much more accurate than state-of-the-art scattering experiments.

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Section: A the Calculation Of Short-range Scattering Matricesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Precision spectroscopy and electron-ion scattering

Gao

2014

Phys. Rev. A

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“…Some improvement of partial cross section has been obtained in the region of the 1s3l final ionic states. They also suggest new assignment of the resonance features using the new eigenchannel treatment of R-matrix theory (Li et al 1997) but this assignment differs greatly from the assignment given by Kiernan et al (1996) and Chung (1997a).…”

Section: Resultsmentioning

confidence: 83%

A 3.5–4.5 GHz Complementary Metal–Oxide–Semiconductor Ultrawideband Receiver Frontend Low-Noise Amplifier with On-Chip Integrated Antenna for Interchip Communication

Azhari

Kimoto

Sasaki

et al. 2010

Jpn. J. Appl. Phys.

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We present a new extended version of the R-matrix method for the calculation of continuum properties in which non-orthogonal orbitals are extensively used for describing both the target states and the R-matrix basis functions. In particular, a B-spline basis is used for the description of continuum states in the inner region and the target states may be obtained from independent calculations. This leads to a generalized eigenvalue problem but has the advantage of requiring much smaller bases for accurate representation of target wavefunctions and to achieve convergence in the close-coupling expansion. The present approach and its code are both applicable to a general atom and their efficiency for low-energy scattering processes is demonstrated by calculating the photoionization of Li. A detailed analysis of the resonance structure is given. Very good agreement with experimental data has been obtained, and considerable improvement in the description of resonances has been achieved in comparison with the standard R-matrix calculations.

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“…(5)- (7). Theoretically, in the present work, by introducing the multipole transition elements into the previous R-matrix code [80,[108][109][110][111][112], the GOSD's in the same energy region were calculated by R-matrix theory, and subsequently the corresponding parameters q i and f ai were deconvolved from the calculated GOSD's. Through a comparison between the experimental and theoretical results, we found that the resonance structures-i.e., q i parameters-agreed well, but differences still existed for the absolute GOSD's, especially for the case with higher momentum transfer.…”

Section: ͑1͒mentioning

confidence: 99%

“…One can refer to previous publications [80,[108][109][110][111][112][113] for a detailed description of R-matrix theory. Here we just give a brief introduction to R-matrix theory and the present implantation of the multipole transition matrix element to the previous codes (also see Ref.…”

Section: R-matrix Theorymentioning

confidence: 99%

Theoretical investigations on the dynamical correlation in double excitations of helium by theR-matrix method

et al. 2004

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The momentum transfer dependence of double excitations of helium were studied theoretically in order to compare with our previous experimental work [Phys. Rev. Lett. 91, 193203 (2003)]. The calculation was carried out by a series of modified R-matrix codes. We elucidate the dynamical correlations in terms of the internal correlation quantum numbers K, T, and A. The generalized oscillator strength densities and Fano profile parameters q, f a , f, and S of doubly excited states n ͑1,0͒ 2 + 1 S e , n ͑1,0͒ 2 + 1 D e , and n ͑0,1͒ 2 + 1 P o were reported as functions of the momentum transfer squared K 2 . The present theoretical work accompanied by our previous experiment leads to a deep understanding of the optically allowed and optically forbidden double excitations of helium.

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Eigenchannel treatment of R-matrix theory

Cited by 28 publications

References 25 publications

Precision spectroscopy and electron-ion scattering

Precision spectroscopy and electron-ion scattering

A 3.5–4.5 GHz Complementary Metal–Oxide–Semiconductor Ultrawideband Receiver Frontend Low-Noise Amplifier with On-Chip Integrated Antenna for Interchip Communication

Theoretical investigations on the dynamical correlation in double excitations of helium by theR-matrix method

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