Sep 20 – 24, 2021
America/Vancouver timezone

Cesiation of RF-Driven Negative Hydrogen Ion Source for the Upgrade of China Spallation Neutron Source

Sep 24, 2021, 7:55 AM
20m
Parallel Session (Contributed Oral) talk Negative ion sources

Speaker

Weidong Chen (Institute of high engery physics, Chinese academy of sciences.)

Description

An RF driven negative hydrogen source is under development for the upgrade of China Spallation Neutron Source (CSNS), which requires an H$^-$ beam current more than 50 mA, and a duty factor of 1.5%$\sim$2%. The ion source produces an H$^-$ beam of 20 mA without cesium injection. After it is cesiated, more than 60 mA H$^-$ beam is extracted. The emittance of the ion beam is measured both with a double-slit scanner and a pepper-pot device. It gives a normalized root of mean square emittance of about 0.4 $\pi\cdot$mm$\cdot$mrad at a beam current of 40 mA, which is much lager than the acceptance of Radio-frequency Quadruple (RFQ) accelerator located downstream. To find the reason, the magnet field distribution of the extraction system is measured. Based on the measurement, the trajectories of the H$^-$ beam and the co-extracted electron beam are simulated with CST program.

E-mail for contact person chenwd@ihep.ac.cn
Funding Information National Natural Science Foundation of China (NSFC), Grant No. U1832163.

Primary author

Weidong Chen (Institute of high engery physics, Chinese academy of sciences.)

Presentation materials