The BEPCⅡis the upgrade project of the Beijing Electron Positron Collider(BEPC).According to the BEPCⅡdouble ring design scheme,a new ring will be added in the existing BEPC tunnel.The machine will provide electron and positron beams with an energy range from 1.0GeV to 2.1GeV for high energy physics research,and an electron beam of 2.SGeV,250mA for synchrotron radiation.So actually there are three storage rings for the BEPCⅡmachine.Due to the limited space of the existing BEPC tunnel and the requirement of high luminosity,the antechamber type vacuum chamber is used,that makes the BEPCⅡmagnets'design and fabrication very difficult.In the paper the general features of the design and fabrication of several kinds of main magnets for the BEPCⅡstorage ring and its interaction region are introduced.And the magnetic field measurement results are presented.
The 1.6GeV synchrotron of China Spallation Neutron Source(CSNS)project is a Rapid Cycling Synchrotron (RCS),which accelerates a high-intensity proton beam from 80MeV to 1.6GeV at a repetition rate of 25Hz.The RCS magnet system consists of 24 dipole magnets(main dipoles),48 quadrupole magnets(main quadrupoles),16 sextupole magnets,some tune shift quadrupoles and corrector magnets.All the magnets are of large aperture for a high beam power of 0.1MW,one design issue is the fringe field at pole end.And the main dipoles and main quadrupoles work at 25Hz repetition rate,the eddy current is an additional issue.In this paper the magnet design of the two kinds of main magnets will be described.
