Q.J. Wang

Study of the halo nucleus 6He through the direct nuclear reactions

Differential cross sections for quasi-elastic scattering, breakup reaction as well as 1n- and 2n-transfer reactions induced by 6He at 25 MeV/nucleon from a 9Be target are reported. The experimental data were analysed in the context of the coupled-channel calculations. The internal structure of 6He is discussed and further studies are proposed.

A multi-electron-beam Cherenkov oscillator operating at mm wavelengths

Abstract A multi-electron-beam Cherenkov maser has the potential of using an electron beam with large spot and an interaction cavity of large transverse dimensions with respect to its operation wavelength to generate high-power microwave radiation. This paper describes a joint experimental research on such a device in which a multi-dielectric cavity of transverse dimensions of 20 mm × 34 mm and a total current of 1036 A at 374 kV, in four sheet beams, were employed to generate 9.1 MW microwave radiation at 36.05 GHz. The conversion efficiency was 2.3%.

High-power multi-electron-beam Cherenkov free-electron lasers at mm wavelengths

Abstract A multi-electron-beam Cherenkov free-electron laser can use a multi-dielectric waveguide to generate high-power coherent radiation at mm wavelength. Presented is a mode analysis of the device, allowing a detailed description of the dispersion relations and field distributions of the waveguide for the important modes and the start current for each mode. The microwave loss of the waveguide and the mode competition problem are also discussed. The device is shown capable of producing radiation at millimeter wavelengths with power an order higher than that uses a dielectric-lined circular waveguide.