scholarly journals INFRARED ABSORPTION LINES IN BORON-DOPED SILICON

1963 ◽  
Vol 41 (11) ◽  
pp. 1801-1822 ◽  
Author(s):  
Konrad Colbow
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Ground State ◽  
Half Width ◽  
Stark Broadening ◽  
Boron Doped ◽  
Doped Silicon ◽  
Spectrometer Slit ◽  
Proper Allowance ◽  
Internal Strains

In boron-doped silicon, optical absorption takes place through the excitation of bound holes from the ground state to excited states. This leads to a line spectrum. Because of a lack of sufficient resolution and a failure to make proper allowance for line distortion by the finite spectrometer slit width, previous authors gave a misleading picture of the low-temperature half-width, the temperature dependence of this half-width, and the onset of concentration broadening at low temperatures.New experimental data are presented and explained by introducing the mechanism of statistical Stark broadening due to ionized impurities, and by modifying Baltensperger's (1953) theory for concentration broadening. At low impurity concentration the width is attributed to phonon broadening (Barrie and Nishikawa 1963) and internal strains (Kohn 1957).

TEMPERATURE DEPENDENCE OF ABSORPTION LINE WIDTH IN BORON-DOPED SILICON

1962 ◽  
Vol 40 (10) ◽  
pp. 1436-1442 ◽  
Author(s):  
Konrad Colbow ◽  
J. W. Bichard ◽  
J. C. Giles
Keyword(s):  
Low Temperature ◽  
Optical Absorption ◽  
Temperature Dependence ◽  
Absorption Line ◽  
Excited States ◽  
Half Width ◽  
Boron Doped ◽  
Doped Silicon ◽  
Spectrometer Slit ◽  
Proper Allowance

In boron-doped silicon, optical absorption takes place through the excitation of bound holes from the ground to excited states. This leads to a line spectrum. Due to a lack of sufficient resolution and a failure to make proper allowance for line distortion by the finite spectrometer slit width, previous authors gave incorrect values for both the low temperature half-width and the temperature dependence of this half-width. In re-evaluating these quantities, two of three previously known lines were found to be doublets. It is found that presently available theory does not explain the results adequately.

ABSORPTION-LINE BROADENING IN BORON-DOPED SILICON

1967 ◽  
Vol 45 (8) ◽  
pp. 2797-2804 ◽  
Author(s):  
J. J. White
Keyword(s):  
Absorption Line ◽  
Excited States ◽  
Half Width ◽  
Line Broadening ◽  
Additional Information ◽  
Boron Doped ◽  
Doped Silicon ◽  
Time Part ◽  
Width Measurements ◽  
First Time

In boron-doped silicon, the excitation of bound holes from the acceptor ground state to the excited states leads to an infrared absorption-line spectrum. In a recent half-width study of the boron absorption lines, Colbow (1963) separated the various line-broadening contributions for the first time. Part of Colbow's half-widths is now found to be due to external strains introduced by the sample mounting. New half-width measurements of "strain-free" mounted boron-doped silicon are presented, Colbow's work is corrected, and additional information regarding the various broadening contributions is given.

The Influence of Slit-Width on the Shape and Intensity of Infra-Red Absorption Bands

1951 ◽  
Vol 4 (2) ◽  
pp. 172
Author(s):  
JB Willis
Keyword(s):  
Experimental Data ◽  
Half Width ◽  
Slit Width ◽  
Absorption Bands ◽  
Infra Red ◽  
Spectrometer Slit

Making certain assumptions as to the shape of infra-red absorption bands and the shape of the slit function of the monochromator, expressions are obtained for the dependence on spectrometer slit-width of the intensity and half-width of absorption bands. Experimental data to confirm the accuracy of these deductions are presented.

1s hole excited states of Be: partial autoionization rates compared with recent experimental data

1991 ◽  
Vol 69 (5) ◽  
pp. 603-605
Author(s):  
D. Petrini ◽  
J. A. Tully
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Cross Section ◽  
Ground State ◽  
Photoionization Cross Section ◽  
Recent Experimental Data ◽  
Auger Decay ◽  
Close Coupling ◽  
University College London ◽  
The University

Auger decay following inner-shell photoexcitation of atomic beryllium is studied using the University College London close-coupling codes. We reproduce some of the features observed experimentally by Krause and co-workers. The vastly predominant decay mode of Be 1s2s2np1P° is to Be+ 1s2np rather than the ground state of Be+ and the theoretical np/2s ratio agrees with the experimental value. The peak observed in the partial photoionization cross section for formation of 1s(2s2p3P) 2P° is due to photoexcitation of 1s2s(3s3p3P) 1P° followed by autoionization. Our theoretical result reproduces this feature. Strong configuration interaction effects limit the accuracy we can achieve for the radiationless decay width.

The (K−,π−) and (π+, K+) Reactions and Λ-Hypernuclear Polarization

1994 ◽  
Vol 117 ◽  
pp. 17-53 ◽  
Author(s):  
K. Itonaga ◽  
T. Motoba ◽  
M. Sotona
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Cross Sections ◽  
Ground State ◽  
Weak Decay ◽  
Angular Distributions ◽  
Theoretical Studies ◽  
Excitation Functions ◽  
Unnatural Parity ◽  
Natural Parity

The theoretical studies of (K−, π−) and (π+, K+) reactions on p-shell targets are presented in the DWIA framework with use of the elementary spin-nonflip and spin-flip amplitudes. Calculations can explain the available experimental data of excitation functions and angular distributions of the (K−, π−) reactions at pK−=800 MeV/c and the (π+, K+) reactions at pπ+ = 1.04 GeV/c. Characteristic and distinguished features of the excitation functions and cross sections are exhibited. Especially it is demonstrated that the (K−, π−) reactions at pK−=1.1 GeV/c and 1.5 GeV/c can excite the unnatural parity states with comparable strength to the natural parity ones. Further interesting is that the (π+, K+) and (K−, π−) reactions with ∼1 GeV/c incident beams can be shown to produce very large polarizations of the produced hypernuclear states. Taking the subsequent deexcitation processes of the excited states into account, we have evaluated the hypernuclear polarization and Λ-spin polarization of the ground state and/or the ground-doublet states at the hypernuclear weak-decay stage, which would play a role in the hypernuclear coincidence experiment.

EFFECTS OF EXTERNAL AND INTERNAL ELECTRIC FIELDS ON THE BORON ACCEPTOR STATES IN SILICON

1967 ◽  
Vol 45 (8) ◽  
pp. 2695-2718 ◽  
Author(s):  
J. J. White
Keyword(s):  
Absorption Line ◽  
Excited States ◽  
Electric Fields ◽  
Stark Effect ◽  
Absorption Lines ◽  
Stark Broadening ◽  
Boron Doped ◽  
Stark Effects ◽  
Boron Acceptor ◽  
Neutral Acceptor

Effects of various electrical perturbations on the boron acceptor states in silicon were studied using low-temperature absorption-line measurements.A uniform external electric field was applied to compensated boron-doped silicon and the "Stark effect" on the boron acceptor absorption lines was observed. The Stark shifts of the excited states were quadratic in the applied field. The Stark broadening of the acceptor absorption lines was attributed to an unresolved partial removal of degeneracy of the excited states. The internal Coulomb fields of ionized impurities also perturb neutral acceptor transitions, resulting in (a) "ionized impurity broadening" of the absorption lines by the screened Coulomb fields of thermally ionized impurities in uncompensated Si(B) silicon at T > 50 °K and (b) "compensation effects" on the absorption lines by the unscreened Coulomb fields of compensationally ionized impurities in Si(B, P) silicon at 4 °K. Observations of these two internal Coulomb held effects are related to the external-field Stark effects. The theories of ionized impurity broadening are discussed briefly and the observed properties of a new absorption line due to compensation are reported.

scholarly journals Pairing and (9/2)n configuration in nuclei in the 208Pb region

2018 ◽  
Vol 177 ◽  
pp. 03004
Author(s):  
M. Stepanov ◽  
L. Imasheva ◽  
B. Ishkhanov ◽  
T. Tretyakova
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Ground State ◽  
Exotic Nuclei ◽  
Low Energy ◽  
Energy Spectra ◽  
Pairing Energy ◽  
Multiplet Splitting ◽  
Wide Range ◽  
Nuclear Masses

Excited states in low-energy spectra in nuclei near 208Pb are considered. The pure (j = 9/2)n configuration approximation with delta-force is used for ground state multiplet calculations. The multiplet splitting is determined by the pairing energy, which can be defined from the even-odd straggering of the nuclear masses. For the configurations with more than two valence nucleons, the seniority scheme is used. The results of the calculations agree with the experimental data for both stable and exotic nuclei within 0.06-6.16%. Due to simplicity and absence of the fitted parameters, the model can be easily applied for studies of nature of the excited states in a wide range of nuclei.

Half-width of infrared absorption lines in boron-doped silicon

1963 ◽  
Vol 5 (2) ◽  
pp. 98-99 ◽  
Author(s):  
K. Colbow ◽  
R. Barrie
Keyword(s):  
Infrared Absorption ◽  
Half Width ◽  
Absorption Lines ◽  
Boron Doped ◽  
Doped Silicon

Dirac phenomenological analyses for the proton scatterings from nickel isotopes

2018 ◽  
Vol 96 (12) ◽  
pp. 1304-1308 ◽  
Author(s):  
Sugie Shim
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Rotational Band ◽  
Ground State ◽  
Optical Potential ◽  
Intermediate Energy ◽  
Channel Coupling ◽  
Optical Potentials ◽  
Nickel Isotopes ◽  
Coupled Channel

Relativistic Dirac coupled channel analyses are performed phenomenologically using an optical potential model for the intermediate energy proton inelastic scatterings from nickel isotopes, 58Ni and 60Ni. The first-order rotational collective model is used for the transition optical potentials to describe the low-lying excited collective states of the ground state rotational band. The complicated Dirac coupled channel equations are solved phenomenologically by varying the optical potential and the deformation parameters to reproduce the experimental data, using a computer program that uses a sequential iteration method. The channel-coupling effects of the multistep transition process for the excited states of the ground state rotational band are found to be strong and lead the calculation results to better agreement with the experimental data when the channel coupling between the excited states is added in the calculation. The Dirac equations are reduced to the second-order differential equations to obtain the Schrödinger equivalent effective central and spin–orbit optical potentials, and the obtained effective potentials are analyzed.

DESCRIPTION OF E1 TRANSITION IN DOUBLY EVEN WELL-DEFORMED NUCLEI

1994 ◽  
Vol 03 (04) ◽  
pp. 1227-1250 ◽  
Author(s):  
V.G. SOLOVIEV ◽  
A.V. SUSHKOV ◽  
N. YU. SHIRIKOVA
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Ground State ◽  
Transition Probabilities ◽  
Wave Functions ◽  
Radial Dependence ◽  
Nuclear Model ◽  
Transition Rates ◽  
Deformed Nuclei ◽  
Dipole Interactions

One-phonon states with Kπ=0− and 1− are calculated within the RPA taking the isoscalar and isovector particle-hole and particle-particle octupole and isovector particlehole dipole interactions into account. General equations of the Quasiparticle-Phonon Nuclear Model are modified. The energies and wave functions of the nonrotational states below 2.3 MeV in 160Gd calculated within this model are in good overall agreement with experimental data. The E1 transition rates in several doubly even well-deformed nuclei are calculated. The influence of the radial dependence of the dipole and octupole interactions on E1 and E3 transition probabilities is investigated. It is shown that the fragmentation of one-phonon states below 2.3 MeV weakly affects the E1 transition rates from 1− states to the ground state. The fragmentation of one- and two-phonon states strongly affect B(E1) values of the transitions from 1− states with energy above 2.5 MeV to the ground states and between excited states. The results of calculating the E1 transition rates are compared with the relevant experimental data.

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