Solar-grade multicrystalline silicon ingots as raw material for solar cells were obtained from upgraded metallurgical silicon by directional solidification in an axial magnetic field. The influence of preparation technology on the microstructural characteristics of silicon ingots was investigated. Governing equations were used to simulate the silicon fluid flow and thermal fields during directional solidification. The results show that appropriately increasing melt temperature and/or decreasing pulling-down rate can be conductive to the growth of a coarse columnar grain. Meanwhile, the axial magnetic field promotes the formation of low-energy ∑3 twin boundaries and reduces the dislocations and impurities, where the total concentration of major metal impurities is with a mean of 0.459 ppmw in the range of 1/9 to 8/9 of height along the growth direction. It is shown from the simulation results that suppressing silicon melt flow in both radial and azimuthal directions and reducing the growth rate in the edge regions contribute to the formation of a flat solid–liquid interface, which is more consistent with the experimental results. Moreover, the formation mechanism of the twins and removal mechanism of the impurities were discussed.

Hermite–Gaussian (HG) laser beam with transverse electromagnetic (TEM) mode indices (m, n) of distinct values (0, 1), (0, 2), (0, 3), and (0, 4) has been analyzed theoretically for direct laser acceleration (DLA) of electron under the influence of an externally applied axial magnetic field. The propagation characteristics of a TEM HG beam in vacuum control the dynamics of electron during laser–electron interaction. The applied magnetic field strengthens the $\vec v \times \vec B$ force component of the fields acting on electron for the occurrence of strong betatron resonance. An axially confined enhanced acceleration is observed due to axial magnetic field. The electron energy gain is sensitive not only to mode indices of TEM HG laser beam but also to applied magnetic field. Higher energy gain in GeV range is seen with higher mode indices in the presence of applied magnetic field. The obtained results with distinct TEM modes would be helpful in the development of better table top accelerators of diverse needs.

The presence of an axial magnetic field in a laser beat wave accelerator enhances the oscillatory velocity of electrons due to cyclotron resonance effect leading to higher amplitude of the ponderomotive force driven plasma wave, and higher energy of accelerating electrons. The axial magnetic field inhibits the transverse escape of electrons and thus causes a growth of the interaction length. The surfatron acceleration of electrons also shows a similar enhancement. A surfatron transverse magnetic field deflects the electrons parallel to the phase fronts of the accelerating wave keeping them in phase with it. However, the electron continues to move away radially.

A double shell z-pinch with an axial magnetic field is considered as a K-shell plasma radiation source. One-dimensional radiation-hydrodynamics calculations performed suggest that this scheme holds promise for the production of the K-shell radiation of krypton (hν ≈ 12–17 keV). As a first step in verifying the advantages of this scheme, experiments have been performed to optimize a neon double-shell gas puff with an axial magnetic yield for the K-shell yield and power. The experiments show that the application of an axial magnetic field makes it possible to increase the K-shell radiation power and reduce the shot-to-shot spread in the K-shell yield. Comparisons between the experiments and modeling are made and show good agreement.