Generation of 1.6 GeV single-particle proton beams

We present a scattering slow extraction method employing a rotating foil in the Rapid Cycling Synchrotron (RCS) to produce a stable 1.6 GeV single-particle proton beam at CSNS. The foil scatters particles on the beam’s edge over multiple turns, with those at large scattering angles being separated and extracted through a Lambertson magnet. By adjusting the scatter foil’s rotational speed and position, we can precisely control the intensity and repetition rate of the extracted beam. This approach enables the efficient extraction of extremely low-intensity proton beams from CSNS-II/RCS. By setting single-particle collimators in the downstream beamline, a single-particle proton beam is achieved. Using 4y, we simulated the scattering slow extraction process in detail, confirming that a stable 1.6 GeV single-particle proton beam can be extracted, the beam energy can be adjusted from 0.8 to 1.6 GeV using the degrader, the time interval between adjacent single protons can be adjusted from hundreds of nanoseconds to tens of microseconds, to meet the needs of different experiments. Both the beam loss and the residual radiation doses are kept at low levels. Published by the American Physical Society 2024