IHEP Beijing, Beijing
CSNS (China Spallation Neutron Source) is a project under construction, which will be a unique facility in China for multi-disciplinary research using neutron scattering techniques. The CSNS accelerator complex is designed to deliver proton beams of 100 kW at Phase One, and progressively upgraded to 200 kW at Phase Two and 500 kW at Phase Three. The upgrading path in beam power is via the increase in linac energy and more accumulated particles in the RCS (Rapid Cycling Synchrotron). Beam losses are key in designing and operating the accelerator complex. Emittance growth, RF trapping loss, and injection/extraction are the major loss sources. The measures to reduce the loss rate and the collimation methods in the accelerators are presented in the talk. Some beam loading effects to the RF systems in the linac and in the RCS, and the uniformization of the beam spot at the spallation target by non-linear magnets are also mentioned.
IHEP Beijing, Beijing
Institute of High Energy Physics, Beijing
A high intensity RFQ has been built with an energy of 3.5 MeV and an average current of 3 mA. Based on this RFQ, we plan on performing a number of experimental tests on beam loss control. A series of beam diagnostic devices such as BPM, BLM, WS have thus been developed. Our work can also be easily applied to the CSNS project.