On January 29, 2019 the China Spallation Neutron Source (CSNS) reached another significant milestone by operating stably at a proton beam power of more than 50 kW.

The important achievement came less than six months after the facility went into full operation. With this achievement, CSNS are optimistic about meeting with the facility’s design goal of 100 kW much sooner than originally planned.    
Increasing beam power for high-intensity accelerators is typically a long and repetitive process. Based on the experience from other neutron facilities, it was projected that after beam commissioning it would take 3 years to achieve the beam’s design parameters. Therefore, the original plan was to reach the design goal of 100 kW by August 2021, three years after CSNS started full operation.

Immediately after its commissioning, CSNS decided to speed up the power-increasing plan to meet with users’ needs for high neutron flux. The CSNS accelerator team has put great effort into increasing beam power. The hardware systems were stable and reliable during the whole month of January, with the facility’s efficiency for user experiments exceeding 93%.

Beam-loss control is one of the major factors into the increase of the beam power. After fine-tuning and optimization, uncontrollable beam loss is lower when operating at 50 kW than at 20 kW, which means uncontrollable beam loss does not increase with increasing beam power.

Measurements of accelerator parts in the tunnel showed that induced radioactivity was much lower than the minimum dose limit required for personnel maintenance, strongly proving that CSNS’s operation is smooth, safe and reliable even at a high beam power rate.