Characteristics of Quantum Magnetosonic-Wave Dispersion

Using the quantum magnetohydrodynamics (QMHD) model, linear dispersion of magnetosonic waves are studied in a quasineutral quantum electron-ion plasma in two distinct regimes of nonrelativistic and relativistic degeneracies considering also the plasma composition effect. It is shown that the paramagnetic spin effects of the degenerated electrons plays a key role in dynamics of magnetosonic waves. The linear wave-speed is found to have minimum value at some degeneracy parameter in such plasmas. This is due to delicate interplay between relativistic degeneracy and the Pauli spin-magnetization. It is also revealed that the plasma composition has significant effect on the linear dispersion in the relativistic degeneracy limit contrary to that of nonrelativistic case and Zeeman energy has significant effect in nonrelativistic degeneracy regime unlike that of relativistic one in the linear perturbation-limit. Current findings can have important applications in both inertial plasma confinement and astrophysical degenerate plasmas.Comment: To appear in IEEE Trans. Plasma Sci. arXiv admin note: text overlap with arXiv:1106.022

Spin-induced localized density excitations in quantum plasmas

In this paper the dominant effect of electron inertia on the dynamics of localized density excitations is studied in a quantum plasma in the presence of electron spin effects. Using the quantum magnetohydrodynamics (QMHD) model including electron tunneling and spin polarization phenomena, it is revealed that the quantum effects such as plasma paramagnetism and diamagnetism play inevitable role on soliton existence criteria in quantum plasmas. Furthermore, it is shown that the magnetosonic localized density-excitation stability depends strongly on the quantum system dimensionality. Two distinct region of soliton stability is shown to exist depending on the value of the electron effective mass, where, the soliton amplitude variation with respect to the external magnetic field strength is quite opposite in these regions. Current findings can be important in the study of dynamical nonlinear wave features in dense laboratory or inertial-confined plasmas.Comment: Paper accepted in journal IEEE Trans. Plasma Sc