SPS MD5044: machine stability characterisation of Gamma Factory SPS Proof-of-Principle Experiment

The Gamma Factory (GF) initiative proposes an innovative method of producing high-energy, high-intensity photon beams via the laser-excitation and subsequent decay of relativistic partially stripped ions stored in the CERN LHC. An initial proof-of-principle experiment in the CERN SPS (GF-SPS-PoP) was proposed in 2019 [3] and would demonstrate the key concepts of this method. Such an experiment would require good control and stability of the SPS beam position and momentum, this was investigated during Machine Development (MD) study 5044. The SPS beam stability at the proposed GF interaction point (IP) location was measured over the millisecond-to-second time-scale. To demonstrate control over the position and angle of the beam at the IP, four-corrector orbit bumps were implemented. The use of radial steering for varying the revolution frequency and, thus, the orbit radius was tested. Here we present the results from these studies towards demonstrating that the stability and control achievable in the CERN SPS would be suitable for the GF Proof-of-Principle experiment.