Impacts of the embedded windings to the field quality of dipole

Cooler Storage Ring (CSR) of Heavy Ion Research Facility in Lanzhou (HIRFL) consists of a main ring (CSRm) and an experimental ring (CSRe). Two particular C-type dipoles with embedded windings are used in the injection beam line of CSRm. They also act as the prototype dipoles of CSRe. The windings are designed to improve the field quality by their trimming current. The current impacts on field homogeneity and multipole components are investigated by a hall sensor and a long coil, respectively. The experiment shows that a field homogeneity of +/- 1.0 x 10(-3) can be reached by adjusting the trimming currents, though the multipole components change correspondingly. In our case, the quadrupole component is decreased to a low level with the octupole, decapole and 12-pole ones increased slightly when the trimming current is optimized.

Application of altimetry data assimilation on mesoscale eddies simulation

Mesoscale eddy plays an important role in the ocean circulation. In order to improve the simulation accuracy of the mesoscale eddies, a three-dimensional variation (3DVAR) data assimilation system called Ocean Variational Analysis System (OVALS) is coupled with a POM model to simulate the mesoscale eddies in the Northwest Pacific Ocean. In this system, the sea surface height anomaly (SSHA) data by satellite altimeters are assimilated and translated into pseudo temperature and salinity (T-S) profile data. Then, these profile data are taken as observation data to be assimilated again and produce the three-dimensional analysis T-S field. According to the characteristics of mesoscale eddy, the most appropriate assimilation parameters are set up and testified in this system. A ten years mesoscale eddies simulation and comparison experiment is made, which includes two schemes: assimilation and non-assimilation. The results of comparison between two schemes and the observation show that the simulation accuracy of the assimilation scheme is much better than that of non-assimilation, which verified that the altimetry data assimilation method can improve the simulation accuracy of the mesoscale dramatically and indicates that it is possible to use this system on the forecast of mesoscale eddies in the future.