Dramatically Enhanced Mechanical Properties of Nano-TiN-Dispersed n-Type Bismuth Telluride by Multi-Effect Modulation.

Bismuth telluride (BiTe)-based alloys have been extensively employed in energy harvesting and refrigeration applications for decades. However, commercially produced BiTe-based alloys using the zone-melting (ZM) technique often encounter challenges such as insufficient mechanical properties and susceptibility to cracking, particularly in n-type BiTe-based alloys, which severely limit the application scenarios for bismuth telluride devices. In this work, we seek to enhance the mechanical properties of n-type BiTeSe alloys while preserving their thermoelectrical performance by a mixed mechanism of grain refinement and the TiN composite phase-introduced pinning effect.

Re-construction of a HPGe detector precise modeling for efficiency calibration.

High purity germanium (HPGe) detector is a preferred choice for determining the activity of the radioactive samples for nuclear diagnostics of Inertial Confinement Fusion (ICF) experiments. Although the amounts of the radiochemical sample are limited, activity measurement at a close distance between the detector window and the radioactive source is a feasible method. Efficiency calibration of gamma rays at a close distance from the surface of a HPGe detector is crucial.

High-precision half-life measurement of Xe and Xe for fuel areal density diagnosing in inertial confinement fusion.

The half-lives of Xe and Xe are important to diagnose deuterium-tritium (DT) fuel areal density in inertial confinement fusion (ICF). In this work, those two half-lives have been measured with HPGe γ-ray spectrometers using the reference source method. Data have been recorded over seven half-lives with three independent measurements for Xe and two for Xe.

Half-life determination of Rb using the 4πβ and 4πβγ-coincidence methods.

Samples of Rb were produced by the irradiation of UO. A series of procedures were applied to extract pure radioactive solution of Rb. Experimental data was recorded by a 4πβγ-coincidence measurement system.

Half-life determination of Kr using the reference source method.

Samples of Kr were produced by (n, 2n) reaction with a DT accelerator, the decay of Kr has been tracked by the reference source method with three High-Purity Germanium (HPGe) detectors. Experimental data were recorded at regular time intervals during measurements covering more than 600 min. The determined half-life of Kr is 71.

Simulation study of the backward-scattering effect in Compton imager.

In the field of nuclear medicine, nuclear security and astrophysics, Compton imaging is a promising technique for gamma-ray source imaging. We are developing a Compton imager using two layers of CdZnTe pixel array detectors. In this paper, the backward-scattering effect within such imagers is numerically studied using Geant4 Monte Carlo Package.

Oxygen implanted Ni/NiO exchange bias system: fabrication, structure and magnetic property.

Ion implantation is used to build a nanometer scale anti-ferromagnetic (AFM) cluster embedded exchange bias (EB) system. Ni film with a thickness of 100 nm is deposited on the Si (100) substrate using magnetron sputtering, 140 keV O+ is chosen to implant into the Ni film to form NiO AFM clusters, of which the size is estimated by X-ray diffraction based on synchrotron radiation (SR-XRD). By measuring hysteresis loop after field-cooling, significant shifts of loop along the applied field are observed.