A Numerical Calculation for Electron Impact Excitation of Copper

The scattering of electrons by atomic copper has been studied using Born approximation and the concept of the generalized oscillator strength (GOS). Differential and total cross-sections for the excitation of the 3d¹⁰ 4p² P state are calculated at incident energies of 100 eV and are compared with other available experimental and theoretical data. The agreement between our calculation for the differential cross-section and the available experimental results is fairly good at the forward angles, while the agreement at large angles is poor. The calculated total cross-sections are compared with the experimental data and those predicted by several theories. It is found that our calculation for the total cross-sections are in a good agreement with the close coupling calculation of Msezane and Henry (1986a, Physical Review A 33, 1631) for incident energies greater than 20 eV. The integrated cross-section measurements of Ismail and Teubner (1995, Journal of Physics B: Atomic, Molecular and Optical Physics 28, 4164) are in good agreement with the present calculation.     

Lateral electric field effects on quantum size confinement in cylindrical quantum dot under parabolic potential

Within the effective mass approximation, we investigated theoretically the ground-state energy of a single particle and the binding energy of the neutral donor impurity (D⁰) affected by a lateral electric field in a parabolic quantum dot (QD). The results show that the electron and the hole ground-state energy and the band to band transition energies shift to lower values (red shift) by increasing the field intensity. The quantum Stark shift (QSS) for the electron increases rapidly in the quasi spherical QD (QSQD) by increasing the lateral field, whereas for the hole it increases monotony. In the cylindrical QDs (CQDs), we found that the QSS for electron and hole increase monotonically. The quantum size, lateral electric field and impurity position effect on the binding energy of neutral donor (D⁰) is studied. Unexpected behavior of D⁰ in quantum well limit (QW), the binding energy of D⁰ is increasing (blue shift) with increasing QD radius R$R$ at the presence of a lateral electric field. It appears that for a fixed size of the QD, the off-center binding energy decreases when the impurity ion is displaced from the center to the QD borders, while it is shifted to lower energy with increasing the field.     

Laser gain by electron collisional pumping of Ar VII–V XII

Gain coefficients have been calculated for transitions of singlet levels ns–np of orbital n=4 and n=5 in magnesium-like ions with atomic numbers Z=18, 19, 20, 21, 22 and 23. Population inversions for 4p and 5p levels in these ions were also calculated, via electron collisional excitation, for electron temperature range of 93–231 eV and electron density range of 10¹⁶–10¹⁷ cm⁻³. Under these plasma conditions, the maximum gain that occurred for 4s–4p transition was at electron temperature of 231 eV and electron density of 4×10¹⁷ cm⁻³. Scaling of the maximum gain coefficients with atomic number Z and the plasma parameters is also presented.     

Electrocortical and Biochemical Evaluation of Antidepressant Efficacy of Formulated Nanocurcumin

Applied Biochemistry and Biotechnology - The present study aims to evaluate the antidepressant efficacy of curcumin nanoparticles on rat model of depression induced by reserpine. Rats were divided...     

Spectral evolution of nano-second laser interaction with Ti target in nitrogen ambient gas

The present work aimed to study the variation in the plasma parameters (temperature and density) of the Ti plasma generated by 1,064 and 532 nm lasers at different ambient N₂ pressures for different delay times. The characterization of the plasma-assisted pulsed laser ablation of the titanium target is discussed. The emission spectra of the titanium plasma produced in the present study have been carefully investigated over the whole UV–NIR (200–1,000 nm) spectral range. Boltzmann plots of suitable spectral lines have been employed to derive the excitation temperature, and the electron density is derived from the Stark widths of the Ti II spectral line at 350.49 nm.     

Spectral evolution of nano-second laser interaction with Ti target in Air

Time-resolved optical emission spectroscopy has been successfully employed to investigate the evolution of plasma produced by the interaction of IR- and visible-pulsed laser beams with a titanium target in ambient air at atmospheric pressure. The characterization of the plasma-assisted pulsed laser ablation of the titanium target is discussed in this study. The emission spectrum produced by the titanium plasma in the wavelength range 200–1,000 nm has been carefully investigated for different experimental conditions. Boltzmann plots have been used in the calculation of the excitation temperature employing Ti II spectral lines at 286.23, 321.71, 325.29, 348.36, and 351.08 nm; this set of lines was tested and proved to be suitable for the measurement of the plasma temperature. The obtained temperature is in good agreement with the one obtained from Ti II spectral lines previously suggested by Hermann et al. [J. Appl. Phys. 77, 2928–2936, 1995, 22]. Moreover, the Stark broadening method has been employed for electron density measurements. In this study, the Stark width of the Ti II spectral line at 350.49 nm was used.     

Electric Dipole Oscillator Strength and Radiative Lifetimes in the Magnesium Isoelectronic Sequence

Oscillator strengths for the singlet 3sns(¹S)-3smp(¹P); (n, m = 3-7), 3snp(¹P)-3smd(¹D); (n = 4-7, m = 3-6) and the triplet 3sns(³S)-3smp(³P); (n = 4-7, m = 3-7), 3snp(³P)-3smd(³D); (n = 4-7, m = 3-6) transitions in the Mg I sequence are calculated in LS-coupling scheme. The Coulomb approximation is used in calculating the radial part of the wave functions, while the angular part is determined using the Racah technique. Lifetimes of the upper 3sns(³S, ¹S); (n = 4-7) and 3snp(³P, ¹P); (n = 3-7) excited states are obtained and compared with the available experimental data.     

Auto-Ionizing States in MgI

Hartree-Fock calculations have been performed for the auto-ionizing levels of the 3pns, 3pnp, 4snp (n = 4 to 7) and 3pnd (n = 3 to 7) series in MgI. The calculated energies of the auto-ionizing states are compared with the available results from photo-absorption measurements and ejected-electron experiments.     

Energy Levels of Doubly Excited States in Argon

Term energies of doubly excited states in argon and argon ions have been determined using single-configuration Hartree-Fock calculation. The energies calculated for KL3s3p⁶nl and KL3s⁶3p⁴nln1 states of Ar show a fairly good agreement with the experimental results obtained by various techniques. However, for Ar+, Ar²+, Ar²+ and Ar³+ states there are no experimental data available in the literature for comparison.