Papers by Keyword: Zeeman Effect

Abstract: We have investigated positronium‒xenon collisions at energies below 100 meV to find a strong temperature dependences of the annihilation rates. A partial wave analysis based on a modified effective range theory (MERT) is tested to explain the temperature dependences and to find significant contributions of the p-wave scattering component. The fact that MERT works well for analyzing positronium‒xenon collisions indicates that positronium is polarized during the collisions as proposed by other theoretical and experimental researchers.

Abstract: The paper analyzes the two kinds magnetic field sensor measuring principle based nuclear Zeeman effect, the signal characteristics are analyzed according to the formula of the sensor output signal, the curve of the sensor maximum output signal VS the earth magnetic field obtained by using the method of combination numerical and experimental. With constant output signal amplitude as a criterion, the amplifier which satisfies the characteristic of the sensor output was designed. To further improve the SNR, program controllable self-tracking band pass filter (PCSTBF) was designed based on the switch capacitor filter and the FFT. The results showed that: the SNR was increased by using the amplifier which contains the PCSTBF, and the bandwidth of the output signal was not reduced.

Abstract: A set of lines in the photoluminescence spectra of 4H-, 6H-, and 15R-SiC in the near-infrared are attributed to Nb-related defects on the ground of doping experiments conducted with 4H-SiC. A model based on a an exciton bound at the Nb-centre in an asymmetric split vacancy configuration at a hexagonal site is proposed, which explains the structure of the luminescence spectrum and the observed Zeeman splitting of the lines.

Abstract: The photoluminescence (PL) of the UD-4 defect is observed in semi-insulating bulk 4H, 6H and 15R SiC. In 4H and 6H SiC the UD-4 defect consists of two families of no-phonon (NP) lines, Ua and Ub, and in 15R SiC it consists of three families, Ua, Ub and U15R. The Ua family in 4H, 6H and 15R all show similar temperature behavior with higher energy NP lines becomming observable at higher temperatures. In the case of the Ub and U15R families, a luminescence line with lower energy than the prominent luminescence line appears at higher temperatures. The polarization and Zeeman measurements suggest that the defect has C3v symmetry.