電子ビーム冷却された陽子ビームのOrdering相転移

The one-dimensional ordering experiment of protons has been performed using the electron cooling at S-LSR. The first proton ordering has been successfully confirmed and the abrupt drop in the momentum spread has been observed at a proton number of 2000 with electron currents of 25 mA, 50 mA and 100 mA. The transition temperature of the proton ordering is 0.17 meV in the longitudinal direction. Below the transition, the longitudinal proton temperature is cooled down to 26 maicro eV, which is close to the longitudinal electron temperature. The results of the beam simulations using the molecular dynamics method also agree well with the experimental results