RF-driven H⁻ sources of long life-time and new LEBT developed at CSNS

An RF-driven ion source has been put into commissioning on the China Spallation Neutron Source (CSNS) accelerator since September 2021. In the last two run cycles, the ion source has operated for 310 and 323 days respectively, with an availability of almost 100%. To fully meet the requirements of the CSNS project Phase-II (CSNS-II), the beam intensity from the linac should be enhanced to above 40mA, and the transverse emittance should be minimized to suppress beam loss during acceleration and transportation. A new test bench consisting of an ion source and a LEBT has been constructed to carry out these optimization and research. The featured functions of the LEBT are associated with proton elimination and electrostatic beam chopping. This report covers the operation status and development of the RF-driven H − source and the new LEBT.