ELENA: AN UPGRADE TO THE ANTI-PROTON DECELERATOR AT CERN

representing the community constructing and later using the AD-ELENA complex CERN has a long tradition of pursuing fundamental physics on a variety of energy scales. For anti-protons CERN famously produced the high-energy SPS beam but also the world’s only and unique sources of low-energy anti-protons – first the Low Energy Anti-proton Ring (LEAR) and thereafter the Anti-proton Decelerator (AD). The scientific demand for low-energy anti-protons at the AD continues to grow. More rapid progress and much higher measurement precision might be possible by upgrading the AD to increase and optimize the number of cold anti-protons that can be trapped and accumulated. To achieve this the construction of an Extra Low ENergy Antiproton (ELENA) ring is proposed which involves both the addition of a small storage ring and electrostatic beam lines to the experiments. The design parameters have been carefully studied and agreed upon over several years. At least during the next decade there is no alternative low-energy anti-proton source for physics to be done now