Visual inspection technology of Z-pinch wire-array assembly parameters

Numerical simulation of the coupling of ultra-wide band electromagnetic pulse into landmine by aperture

“…[5] Although such shells are made of metal, conductive plastic or other electromagnetic shielding materials that effectively improve the anti-interference capacity against the UWB-EMP, there are often apertures (or slits for manufacturing necessity) on landmine shells as formulated from the annectent devices, and through the aperture coupling operations, the UWB-EMP would easily impose a coupling effect upon the electronic fuse. [6,7] To improve the capability of resisting UWB-EMP interference, the coupling mechanism as well as the weak segment of EMP in mines ought to be analyzed and understood in terms of a technical experiment or numerical simulation, so as to give a reference for the electro-magnetic defense reinforcement. Reference [8] numerically studied the coupling of UWB-EMP in mines made of plastic shells with rectangular coordinates FDTD, and demonstrated some coupling results of electromagnetic distributions as presented for different incident distances and angles from the antenna to the mine.…”

“…Equation (7) shows that the differential equation cannot be used at r = 0. Similarly, H r singularities exist in the axial direction.…”

A 980 nm Yb-doped single-mode fibre laser with 946 nm Nd:YAG laser as pump source

“…Compared with other doped fibre lasers, Ybdoped fibre lasers (YDFL) can obtain high quantum conversion efficiency and suffer neither excited state absorption (ESA) nor concentration quenching effect. [3] Generally, most of the high-power YDFL operate in a four-level system (1030 nm −1200 nm), which have been widely used in laser processing areas. [4,5] However, as the increasing number of channels of dense wavelength division multiplexing demands higher and higher output powers of erbiumdoped fibre laser amplifier, [6] the high-power highquality quasi-three-level YDFL at 980 nm which is an important pump source of erbium-doped fibre amplifier also becomes one of hot research areas in the field of fibre laser.…”

Theoretical investigation of a backward wave oscillator

“…Relativistic backward wave oscillator (RBWO), whose output microwave power relates closely to the guiding magnetic field [1][2][3] , is one of the most promising microwave devices. There are many theoretical results [4][5][6] on the relationship between the output microwave power and the parameters of the electron beam, which are attained on the condition of the infinite guiding magnetic field and can't reveal the relationship between the output microwave power and the guiding magnetic field.…”