The China Spallation Neutron Source (CSNS) operated smoothly at a beam power of more than 50kW on Jan. 29, marking another significant milestone for the facility.
The important achievement came less than six months after the facility went into full operation. Based on this breakthrough, scientists are expecting to meet the facility's design goal of 100kW much sooner than originally planned.
Increasing beam power for high-intensity accelerators always requires patience. Based on the experience of other facilities, designers had projected it would take three years after beam commissioning to be able 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.
As the first spallation neutron source in China, CSNS decided to speed up the plan in order to meet users' needs for high neutron flux. The CSNS accelerator team has put much effort into increasing beam power. Each hardware system was stable and reliable during the whole month of January, with the facility's efficiency for user experiments exceeding 93%.
Good beam loss control is one of the key factors in increasing beam power for high-intensity accelerators. After fine-tuning and optimization, uncontrollable beam loss is lower when operating at 50kW than at 20kW, 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 dose limit required for manual maintenance, thus strongly proving that CSNS's operation is smooth, safe and reliable even at high beam power.