Xia Zonghuang

Stopping powers of C, Al, Ti, Cu, Nb and Ag for 16O and 19F ions

Abstract Stopping powers of C, Al, Ti, Cu, Nb and Ag for 0.4–5.7 MeV 16 O and 19 F ions were measured with the technique of transmission. The results were compared with the predictions of the LSS theory, SRIM2000 calculations and previous experimental data. Significant discrepancy was observed in the comparison. Apparent Z 2 -oscillation was exhibited by the present stopping power data.

Stopping power for MeV 12C ions in solids

Abstract The stopping powers for 0.3–6.4 MeV 12 C ions in C, Al, Ti, Cu, Nb and Ag have been measured with the transmission method. The experimental data on stopping power are compared with evaluated values using LSS theory, ZBL semiempirical model predictions and previous experimental data. The results show that there is significant discrepancy between present work and LSS theory; for C in Al, ZBL calculations quite agree with our measurements, yet for C in other stoppers, those cannot reproduce most of present experimental data; our work consists mostly with previous measurements. Moreover, present stopping power data exhibit apparent Z 2 -oscillation.

Stopping power for MeV energy Au ions in silicon

Abstract The range distributions of Au ions with three implanted energies (Ei=1230, 2130, 3030 keV) in silicon were measured using Rutherford backscattering technique (RBS). The projected ranges were obtained and were larger than those of the TRIM-91 calculation. The nuclear stopping power Sn calculated by Biersack general potential and the electronic stopping power Se=A(E/E0)P generated from LSS theory were used to fit the experimental data. Then the values of parameters A and P in the electronic stopping power formula Se=A(E/E0)P were determined. Significant discrepancies of the electronic stopping power between the experimental results and the TRIM-91 calculations were observed.

Stopping powers of A1 for MeV Si ions

Abstract Stopping powers of A1 film for Si ions (0.8–6.4 MeV) have been measured with Rutherford backscattering (RBS) technique. A new method to determine the stopping powers for low-velocity heavy projectiles was used. The experimental results of the stopping powers for low-velocity Si ions are smaller than those of the TRIM code and LSS theory.

Identification and Rutherford Backscattering Measurement of MeV Carbon Cluster Ions

The MeV carbon cluster ions provided by 1.7 MV tandem accelerator were identified and Rutherford backscattering spectra of MeV carbon cluster ions on the gold film were measured with silicon surface barrier detector.

A microscopic mechanism of low temperature helium release

4He ions of various energies and at various doses were implanted into three kinds of samples: TiH2 films, high purity Ti pieces as-received and after hydrogenation. Thermal release of helium was monitored in-situ by proton-enhanced backscattering. Low-temperature helium release was observed at T ≤ 573K. Single jump model was used to calculate the active energies for the release. Based on the observations, a mechanism of helium cluster-vacancy complex (HemVn-Vi) for low-temperature helium release is proposed.

Stopping Powers of Bromine and Carbon in Silver

The stopping powers of Br and C in Ag film have been measured with the method of elastic recoil detection in energy range 0.28-0.42 MeV/amu. The results have been compared with the theoretical calculations of TRIM-90.

OBSERVATION OF PHOTOREFRACTIVE EFFECT OF KNbO 3 CRYSTAL AT μW ILLUMINATION

The photorefractive effects of the as-grown and proton-implanted KNbO3 crystals were studied by two-wave mixing at 62.2µW/cm2 illumination. At this pump power level, the as-grown crystal showed little photorefractive effect, while the proton-implanted crystal showed an obvious effect. Furthermore, there seemed to exist two photorefractive gratings with response times of 22.54 and 1596.30s, at 62.2µW/cm2 pump power level, in the proton-implanted sample. This phenomenon has been attributed to the influence of proton-implantation.

Formation of optical waveguides in KNbO3 by MeV boron ion implantation

Abstract Planar optical wave guides were formed in KNbO 3 by MeV boron ion implantation. The experimental results demonstrated that MeV heavy ion implantation in KNbO 3 produces optical waveguides with high quality.

Energy Loss and Straggling of 4He Ions in Havar

The energy loss and energy straggling of 4He ions in Havar foil were measured with the transmission geometry. The present result of energy loss has good agreements with that of the previous experiment and the semi-empirical predictions, while for the energy straggling data significant deviation was found at lower energies compared with the predictions of Bohr theory.