[en] To operate divertor experiment, an in-vessel cryopump was installed on the EAST tokamak in 2008. It can limit gas impurity recycling from divertor region into core plasma area, and provide plasma density control with toroidally distributed high pumping speed. In this paper, the designing and manufacturing is basically described. Most parts are manufactured in ASIPP, except for some procedures such as laser cutting, plasma-spray coating, and pipe annealing. For this first in-vessel cryopump, liquid helium and nitrogen supplying system is upgraded. Functional tests for this cryopump show a good radiation shield and pumping capability. A campaign utilizing this device for divertor physics research has been successful.

[en] (Mn, N)-codoped ZnO films were grown on fused silica substrates by reactive magnetron cosputtering. X-ray diffraction measurements reveal that the films have the single-phase wurtzite structure with c-axis preferred orientation. X-ray photoelectron spectroscopy studies indicate the incorporation of both divalent Mn²⁺ and trivalent N^3- ions into ZnO lattice. Acceptor doping with nitrogen partly compensates the ''native donors,'' which results in a low electron concentration of 3.16x10¹⁶ cm^-3 though p-type conductivity is not achieved. (Mn, N)-codoped ZnO films show significant ferromagnetism with Curie temperature above 300 K. The mechanism of ferromagnetic coupling in codoped ZnO is discussed based on a bound magnetic polaron model

[en] We have studied the structural and optical properties of ZnO thin films prepared by thermal oxidation of ZnS films deposited by plasma assisted electron-beam evaporation on Si(1 0 0) substrates. The transformation from zinc blende ZnS to hexagonal wurtzite ZnO is confirmed by Raman and X-ray diffraction (XRD) measurement. For the sample thermally oxidized at 600 ^oC for 2 h, a novel UV emission peak I_x located at 3.22 eV (385 nm) has been observed. The temperature-dependent photoluminescence spectra show that the integrated intensity of I_x increases exponentially with increasing temperatures within the measuring temperature range, from 80 to 300 K, but the peak position remains nearly constant. We explain this behavior in terms of electron tunneling into the radiative recombination centers

[en] Mn-passivated nanocrystalline ZnO:S thin films were fabricated by thermally oxidizing Mn-doped ZnS (ZnS:Mn) films prepared by electron beam evaporation. Mn was introduced to passivate the surface defects of ZnO and to improve the optical properties. X-ray diffraction (XRD) and photoluminescence (PL) spectra at 81.9 K indicated the S content in ZnO thin film gradually decreased with increasing annealing temperature. The fitted result of the temperature-dependent PL spectra in the range from 81.9 to 302.2 K showed that S dopant could broaden the optical band gap energy of ZnO. Room temperature PL spectra confirmed that the ultraviolet peak shifted to lower energy with the decrease of S content in the thin film because of the Burstein-Moss effect

[en] ZnO particles embedded in SiO₂ thin films were prepared by a radio-frequency magnetron sputtering technique. X-ray diffraction (XRD) and optical-absorption spectra showed that ZnO particles with hexagonal wurtzite structure had been embedded in the SiO₂ matrix, and the size of ZnO particles increased with increasing annealing temperature from 773 to 973 K. Raman-scattering and Fourier transform infrared (FTIR) spectrum measurements also confirmed the presence of ZnO particles. When the annealing temperature was lower than 973 K, room-temperature photoluminescence (PL) spectra showed dominative deep-level emissions in the visible region and very weak ultraviolet emissions. As the annealing temperature increased to 973 K, an emission band in the ultraviolet region besides the emissions from free and bound excitons recombination was observed in the low-temperature PL spectra. The origin of the ultraviolet emission bands was discussed with the help of temperature-dependent PL spectra. When the annealing temperature was higher than 973 K, Zn₂SiO₄ particles were formed, as shown by XRD and FTIR results