Status of The China Spallation Neutron Source
Abstract: Neutron scattering, as a tool for the investigation of materials in all their diversity and complexity, was pioneered in the north American in the 1950s. Early instrumental techniques were quickly established to unravel atomic structures of materials as well as atomic dynamics, for which Cilff Shull and Bert Brockhouse were awarded the Nobel prize in physics in 1994, many years after their pioneering work but at a time when neutron scattering was applied and a truly indispensable tool to a very wide spectrum of scientific fields. Production of neutrons has been limited to fission reactors with the flagship named Institut Laue Langevin (ILL), being built in the late 1960s in Grenoble France. It’s not until 1980s when the world’s first proton-driven neutron source was constructed and powerful enough to challenge the supremacy of the ILL. This so-called spallation neutron source, namely ISIS, was built close to Oxford in the UK. Spallation neutron sources are pulsed in nature with very high peak brightness, generating significantly less heat per useful neuron comparing to fission reactors thus hold a significant technological advantage over reactors. These sources also represent a very high level of scientific readiness as the design and construction of such sources require a large multidisciplinary team with special expertise including but not limited to: neutron science, neutronics, accelerator, control system, engineering, data management, radiation safety etc. For almost 30 years following ISIS’s commissioning, only 3 large spallation neutron sources were constructed: SINQ at Switzerland, SNS at Oak Ridge, USA, and J-Parc at Japan, with SINQ being the only continuous spallation neutron source.
In early 2010s, the Institute of High Energy Physics (IHEP) in China took on a tremendous challenge to build the first spallation neutron source (namely CSNS, China spallation neutron souce) within a developing-country setting. After almost 6 years of construction and a spending of more than 330 M USD, in Aug. 2017, CSNS received its first neutrons. In 2018, 3 neutron instruments (a neutron powder diffractometer, a small-angle neutron scattering diffractometer and a polarized neutron reflectometer) entered their commissioning phase. Meanwhile, 7 more neutron instruments are being constructed, with 10 more being planned with proposals in preparation. CSNS is commissioning with 25 kW proton beam power, with a two-phase power upgrade plan to 200 kW and 500 kW, respectively. A second target station is also planned which will add another 20 neutron instruments to currently planned suite, greatly expanding the capabilities and outreach of CSNS. CSNS is visioned not only to provide a unique research platform for materials studies for users worldwide, but also serves the mission to advance the development and applications of neutron technologies at large.
In this talk I will give an introduction on neutron techniques and neutron sources, followed by the overview of CSNS, its design, construction, commissioning and future.