[en] RF stacking process for heavy ions is analyzed in HIRFL cooler storage ring (HIRFL-CSR). A RF cavity for heavy ions stacking is designed according to the requirement of the stacking processes. Its frequency range is 18.0-28.0 MHz and peak RF voltage is 20.0 kV. The other main parameters of the cavity are obtained by using transmission line theory and SUPERFISH code

[en] Cooler Storage Ring (CSR), and upgrading program planned at the Heavy Ion Research Facility in Lanzhou (HIRFL), will supply beams with higher quality and intensity. Space charge effects should be considered due to this magnitude of intensity in CSR. The concept and some phenomena of space charge effects are discussed. Space charge intensity limit and space charge tune shift of normal CSR operation are given. It is of significance for the construction and operation of the future facility

[en] The simulation of accelerating process for HIRFL cooler storage ring (CSR)has been performed by taking into account the ions' synchrotron oscillation. The distribution of particles at different time in longitudinal phase space is shown. The main parameters such as RF frequency, synchronous phase, RF voltage, beam length, momentum spread and beam energy against time are given

[en] Low-temperature magnetic and electric properties in hexagonal multiferroic compound YbMnO_3 were studied. The Mn"3"+ spin moments order at T_N = 85 K and reoriented around 43.5 K, leading to the magnetic phase transition from B_2(P6_3cm) → A_2(P6_3cm). The concomitant ferroelectric polarization is observed and explained microscopically by the destruction of initial symmetric relationship of the polarization between the upper and lower half of the magnetic unit cell. The asymmetry of the polarization vs temperature curves under opposite poling voltage revealed the pinning effect of the defects on the electrical polarization

[en] In this study, Monte Carlo simulation was performed on a Poshwich detector for measuring radioactivity of β particles in radioactive aerosol. The detector model consists of plastic scintillator and BGO crystal, with aluminum foil in the front to stop α particles and considerations to prevent the γ-rays from affecting the β-ray detection. Code Geant4 was used to calculate the energy deposition in the scintillators and their attenuation coefficient, The size and the structure of the detector ware determined based on the simulation. (authors)

[en] We studied the temperature effect on magnetic and electrical properties in bulk SrFe_1_2O_1_9 prepared by conventional ceramic technique. The jumping behavior of magnetization has been observed under the zero-field-cooling mode, but disappeared under the field-cooled cooling mode. The spin moment of iron ions reorients below 50 K leading to the magnetic structure changes. Magnetic parameters, saturation magnetization (Ms) and coercivity field (Hc), show opposite tendency with temperature throughout the measuring range, which is mainly ascribed to the Fe"3"+ ions situated at 4f_2 and 2b sites. The curves of electrical polarization P vs temperature T under different external magnetic field indicate the existence of ferroelectricity and magnetoelectric coupling effect at low temperature, and the transition temperature T_P is about 120 K. (orig.)