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JTAP-01.10.2023

Journal of Theoretical and Applied Physics (JTAP)

Editor-in-Chief: Davoud Dorranian, PhD

Online ISSN: 2251-7235

Print ISSN: 2251-7227

Publishes Bimonthly

Study on higher order azimuthally polarized Laguerre–Gaussian mode beams with high NA lens

AbstractThe intensity distributions near the focal point for tight focusing of azimuthally polarized Laguerre–Gaussian beam including higher order modes are calculated based on vector diffraction theory. For higher order as well as the fundamental lower order mode A-TEM01*, a small focal hole at the centre is obtained for the focusing under high NA lens. In […]

The effect of beam and plasma parameters on the four modes of plasma-loaded traveling-wave tube with tape helix

AbstractField theory is applied to analyze the behavior of the electromagnetic wave in the presence of a solid electron beam and magnetized plasma-loaded tape helix traveling-wave tube. The obtained dispersion relation implicitly includes azimuthal variations and all spatial harmonics of the tape helix. Results indicate that the frequency and the phase velocity of (Xbp − Xp) and […]

Evolution of solitons and their reflection and transmission in a plasma having negatively charged dust grains

AbstractTheoretical calculations are carried out for studying soliton’s reflection and transmission in an inhomogeneous plasma comprising ions, two temperature electrons and negatively charged dust grains. Using reductive perturbation technique, relevant modified KdV equations are derived for the incident, reflected and transmitted solitons. Then a coupled equation is obtained based on these mKdV equations, which is […]

Number projected isovector neutron–proton pairing effect in odd-mass nuclei

AbstractA formalism which enables one to strictly conserve the number of particles when taking into account the isovector pairing correlations is presented in the case of odd-mass nuclei. With this aim, we had to first establish the expression of the projector for such systems. Expressions of the ground state and its energy have been exhibited. […]

A study of the validity of the efficiency transfer method to calculate the peak efficiency using γ-ray detectors at extremely large distances

AbstractThe full-energy peak efficiency (FEPE) curves of the (2″ × 2″ and 3″ × 3″) NaI (Tl) detectors were measured at seven different axial positions from their surfaces. The calibration process was done using radioactive point sources, which produce a wide energy range from 59.53 up to 1,408.01 keV. This work has been undertaken to explain the effects of source […]

Low-intensity UV effects on optical constants of PMMA film

AbstractEffects of low-intensity UV treatment on the optical constants of red BS dye-doped polymethyl methacrylate (PMMA) film including refractive index, extinction coefficient, real and imaginary parts of dielectric constant, band gap energy, Urbach energy, and refractive index dispersion parameters are measured and calculated. Changes in optical constants mainly occurred in the UV–VIS range. Red BS […]

Effect of negative oxygen ions on the characteristics of plasma in a cylindrical DC discharge

AbstractLangmuir probe measurements are performed in cylindrical dc glow discharge plasma. Plasma was generated in an evacuated glass tube, with circular plane disk electrodes. Measurements were carried out at different points along the axis of tube for different working pressures of pure argon and mixture of argon–oxygen gasses to obtain the plasma density and temperature […]

Soliton reflection in a magnetized inhomogeneous warm plasma: effect of ionization

AbstractThe reflection of nonlinear solitary waves is studied in a plasma under the effect of an external magnetic field and constant ionization along with finite ion temperature. To investigate the reflection of solitary waves, relevant modified Korteweg–deVries equations for the right and left going waves are derived, and coupled at the point of reflection for […]

Quasi monoenergetic electron bunch generation by frequency variation laser pulse in magnetized plasma

AbstractThe effect of the frequency variation of laser pulse in uniform magnetized plasma is considered in one-dimensional laser wakefield acceleration and carried out particle simulation. It is shown that wakefield amplitude is increased threefold for the negative Gaussian chirped laser pulse in the magnetized plasma. In our simulation, electrons with initial energy about 0.3 MeV with […]

Plasma effect in tape helix traveling-wave tube

AbstractA linearized relativistic field theory of a plasma-loaded helix traveling-wave tube is presented for a configuration where a solid electron beam propagate through a sheath helix enclosed within a loss-free wall in which the gap between the helix and the outer wall is filled with a dielectric. Numerical study of the effect of plasma density […]