scholarly journals Hyperfine Structure and Relaxation Times of 4-Oxo-TEMPO/Methyl Alcohol Solutions in Weak and Strong Fields

1991 ◽  
Vol 46 (11) ◽  
pp. 976-982 ◽  
Author(s):  
M. Sünnetçioğlu ◽  
G. Bingöl ◽  
R. Sungur
Keyword(s):  
Free Radical ◽  
Hyperfine Structure ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Double Resonance ◽  
Relaxation Times ◽  
Electronic Relaxation ◽  
First Order ◽  
Saturation Method ◽  
First Order Perturbation

AbstractThe hyperfine structure of the 4-Oxo-TEMPO (2,2,6,6-tetramethyl-4-oxopiperidin-oxyl-l) free radical was investigated. Theoretical investigation includes four methyl groups protons close to the unpaired electron. Energy levels and transition probabilities were found by using second order and first order perturbation theory, respectively, and from these data theoretical spectra of the free radical were obtained. Diluted solutions in CH3-OH were prepared and the spectra were recorded with a double resonance spectrometer (1.53 mT) and Varian E-9X-band ESR spectrometer (~0.3 T). In order to understand the influence of time dependent phenomena on the linewidths, electronic relaxation times of 4-Oxo-TEMPO and its perdeuterated form (PDT) were measured at two different fields by using cw saturation method.

Energy levels and radiative transitions of the K-shell excited sextet states in boron-like sulfur ion

2016 ◽  
Vol 94 (10) ◽  
pp. 1054-1060 ◽  
Author(s):  
Yan Sun ◽  
CuiCui Sang ◽  
KaiKai Li ◽  
XinYu Qian ◽  
Feng Hu ◽  
...  
Keyword(s):  
Fine Structure ◽  
Relativistic Effect ◽  
Transition Probabilities ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Variation Method ◽  
First Order ◽  
Radiative Transitions ◽  
First Order Perturbation

Theoretical calculations are reported for energy levels and transition probabilities of the K-shell excited sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) for the astrophysically important element sulfur. Energy levels, fine structure splittings, and transition parameters of the high-lying sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) in boron-like sulfur ion are calculated with the multi-configuration Rayleigh–Ritz variation method. To obtain the accurate energy level, the relativistic corrections and mass polarization effect are included by using the first-order perturbation theory. Configuration structures of these sextet series are assigned according to the energies, percentage contributions of basis states to the eigenvector, relativistic effect corrections, and verification of fine structure splittings. The oscillator strengths, transition probabilities, and wavelengths of electric-dipole transitions between 6So,e(m) and 6Pe,o(m) (m = 1–7) states are also systematically calculated and discussed.

scholarly journals Intercombination Transitions between Levels X1Σg+ and A 3Πu in C2

1987 ◽  
Vol 120 ◽  
pp. 103-105
Author(s):  
J. Le Bourlot ◽  
E. Roueff
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Wave Functions ◽  
Spin Orbit Coupling ◽  
Energy Matrix ◽  
First Order ◽  
Emission Transition ◽  
Intercombination Transition ◽  
The One ◽  
Potential Curves

We present a new calculation of intercombination transition probabilities between levels X1Σg+ and a 3Πu of the C2 molecule. Starting from experimental energy levels, we calculate RKR potential curves using Leroy's Near Dissociation Expansion (NDE) method; these curves give us wave functions for all levels of interest. We then compute the energy matrix for the four lowest states of C2, taking into account Spin-Orbit coupling between a 3Πu and A 1Πu on the one hand and X 1Σ+g and b 3Σg− on the other. First order wave functions are then derived by diagonalization. Einstein emission transition probabilities of the Intercombination lines are finally obtained.

RELATIVISTIC ENERGY, OSCILLATOR STRENGTHS AND TRANSITION RATES OF THE 1s2 2 ln l 1S(m)(n =2–6, m1–5) STATES FOR Be-LIKE SYSTEM

2005 ◽  
Vol 16 (06) ◽  
pp. 951-968 ◽  
Author(s):  
MENG ZHANG ◽  
BING-CONG GOU
Keyword(s):  
Experimental Data ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Relativistic Energy ◽  
Transition Rates ◽  
Isoelectronic Sequence ◽  
Polarization Effects ◽  
First Order ◽  
Variational Calculations ◽  
First Order Perturbation

Variational calculations are carried out with a multiconfiguration-interaction wave function to obtain the relativistic energies of the 1s2 2 ln l 1 S (m)(n =2–6, m1–5) states for the beryllium isoelectronic sequence (Z =4–10). Relativistic corrections and the mass polarization effects are evaluated with the first-order perturbation theory. The identifications of the energy levels for 1s2 2 ln l 1 S (m)(n =2–6, m1–5) states in the Be-like ions are reported. The oscillator strengths, transition rates and wavelengths are also calculated. The calculated results are compared with other theoretical and experimental data in the literature.

Investigation of Rotational Relaxation by Double Resonance and Stark Switch Techniques

1980 ◽  
Vol 35 (8) ◽  
pp. 832-840
Author(s):  
W. Schrepp ◽  
H. Dreizler ◽  
A. Guarnieri
Keyword(s):  
Double Resonance ◽  
Relaxation Times ◽  
Experimental Methods ◽  
Rotational Relaxation ◽  
Triple Resonance ◽  
Static Electric Field ◽  
First Order ◽  
Four Levels ◽  
Relative Change

Abstract For the four rotational levels JK₋K₊ = 101, 110,212 and 221 of ethylene oxide all possible four level double resonance experiments for dipole allowed transitions have been performed to investigate collisional effects and to determine the relative change of signal intensity, η = ⊿I/I, due to high power pump radiation. The T1 and T2-relaxation times have been measured for all dipole allowed transitions within these four levels. A combination of the data obtained from both experimental methods allows the determination of rate and bath constants taking into account only first order dipolar transitions. No further restrictions have been used. This approximation is supported by a triple resonance experiment. In addition to the pure gas investigation in the absence of external fields, rotational relaxation has been studied in the presence of a static electric field and in a mixture with hydrogen.

Quantization of coupled orbits in metals

1962 ◽  
Vol 270 (1340) ◽  
pp. 1-13 ◽  
Keyword(s):  
Magnetic Field ◽  
Perturbation Theory ◽  
Fourier Analysis ◽  
Level Density ◽  
Energy Levels ◽  
Interference Effects ◽  
Level System ◽  
First Order ◽  
Simple Network ◽  
First Order Perturbation

The failure of semi-elassical quantization of electron orbits in metals in the presence of a strong enough magnetic field (magnetic breakthrough) is discussed in an elementary fashion by means of first-order perturbation theory. The interference effects, which arise when orbits about different centres are coupled, are reproduced in a simple network analogue. Exact analysis of the network shows how the energy levels are broadened by the coupling and eventually reform into a different set of levels. Fourier analysis of the level density reveals what might be observed in the de Haas—van Alphen effect when magnetic breakthrough is significant, and it is concluded that in principle the whole evolution of the level system should be observable.

Investigation of Self-and Foreign Gas Collision-induced Transitions between M-resolved Rotational Levels of OCS

1982 ◽  
Vol 37 (4) ◽  
pp. 358-370 ◽  
Author(s):  
H. Mäder
Keyword(s):  
Energy Levels ◽  
Double Resonance ◽  
Rotational Energy ◽  
Level System ◽  
First Order

Abstract Four-level MW-MW double resonance experiments on rotational Stark levels j = 0, 1, 2 and 3 of OCS have been performed to investigate transfer of rotational energy by collisions of OCS with OCS, He, Ne, Ar, Kr, H2, N2, O2, and CH3F. Theoretical arguments are given for the interpretation of the experimentally determined η-values by considering Bloch-type equations of an "embedded" four-level system with ±M degeneracy of the energy levels. The results indicate significant deviations from first order dipole collisional interaction.

scholarly journals NONCOMMUTATIVE SPACE CORRECTIONS ON THE KLEIN–GORDON AND DIRAC OSCILLATORS SPECTRA

2011 ◽  
Vol 26 (29) ◽  
pp. 4991-5003 ◽  
Author(s):  
ROBERTO V. MALUF
Keyword(s):  
Perturbation Theory ◽  
Energy Levels ◽  
Zeeman Splitting ◽  
Nonrelativistic Limit ◽  
Order Perturbation ◽  
Noncommutative Space ◽  
First Order ◽  
Commutative Space ◽  
Klein Gordon ◽  
First Order Perturbation

We consider the influence of a noncommutative space on the Klein–Gordon and the Dirac oscillators. The nonrelativistic limit is taken and the θ-modified Hamiltonians are determined. The corrections of these Hamiltonians on the energy levels are evaluated in first-order perturbation theory. It is observed a total lifting of the degeneracy to the considered levels. Such effects are similar to the Zeeman splitting in a commutative space.

scholarly journals Collisional “Selection Rules” for Asymmetric Top Molecules

1977 ◽  
Vol 32 (6) ◽  
pp. 614-619 ◽  
Author(s):  
W. Schrepp ◽  
H. Mäder ◽  
H. Dreizler ◽  
D. Sutter
Keyword(s):  
Double Resonance ◽  
Order Perturbation ◽  
Microwave Range ◽  
Selection Rules ◽  
First Order ◽  
Asymmetric Top ◽  
Rotational Transitions ◽  
Theoretical Results ◽  
First Order Perturbation

Abstract Selection rules for collision-induced rotational transitions of asymmetric top molecules are derived by first order perturbation treatment. The theoretical results are in agreement with the results from four-level double resonance experiments in the microwave range.

Inner-shell excitation energy levels, and radiative and Auger transitions of B-like nitrogen

2016 ◽  
Vol 94 (11) ◽  
pp. 1119-1124
Author(s):  
Chao Chen ◽  
Bingcong Gou ◽  
Chunmei Zhang
Keyword(s):  
Excitation Energy ◽  
Saddle Point ◽  
Energy Levels ◽  
Radiative Transition ◽  
Transition Rates ◽  
First Order ◽  
Complex Rotation ◽  
Background Data ◽  
Rotation Methods ◽  
First Order Perturbation

Inner-shell excitation energy levels, and radiative and Auger transitions of the 1s2s22p2, 1s2s22p3p, 1s2s2p3, 1s2p4, and 1s2p33p 2,4L (L = S, P, D) resonances for B-like nitrogen are calculated using the saddle-point variation and saddle-point complex-rotation methods. The first-order perturbation theory is used to calculate relativistic and mass polarization corrections. Present autoionization energy levels, radiative transition rates and wavelengths, Auger rates, and Auger electron energies for these resonances agree well with theoretical and experimental data available in the literature, and will provide valuable background data for astrophysics and plasma physics in future.

Studies of energy levels, hyperfine structure, and transition probabilities for neutral silicon

2016 ◽  
Vol 94 (4) ◽  
pp. 359-364 ◽  
Author(s):  
Miao Wu ◽  
Guojie Bian ◽  
Xiangfu Li ◽  
Min Xu ◽  
Quanping Fan ◽  
...  
Keyword(s):  
Hyperfine Structure ◽  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Structure Constant ◽  
Hartree Fock ◽  
Hyperfine Structure Constant ◽  
Experimental Values ◽  
Good Agreement

The multi-configuration Dirac–Hartree–Fock method and active space approach are used to investigate the energy levels, hyperfine structure constants, and transition probabilities of a neutral silicon atom. The contributions of Breit interactions and quantum electrodynamics correction are considered. Compared with other theoretical and experimental values of energy levels, our values are in good agreement; the discrepancies of the majority of energy levels calculated are within 1% of experimental values, and the energy levels calculated are very close to other theoretical values. The number of energy levels we considered is larger than that of any other theoretical calculations. The values of the hyperfine structure constant A of the radioactive 29Si atom that we calculated are in good agreement with experimental values. From these results we can predict the hyperfine structure constant A of other states of 29Si where no other theoretical results are available. The transition probabilities of neutral silicon have also been calculated and discussed.

Sign in / Sign up

Export Citation Format

Share Document