Recent highlights from the CERN-AD

The Antiproton Decelerator and cooling ring (AD) provides dense and cold beams of antiprotons to low energy experiments for the study of basic properties of antiprotons and antihydrogen. It combines stochastic cooling (at 3.5 and 2 GeV/c) with electron cooling at 0.3 and 0.1 GeV/c. In 2002 the AD gave beam during more than 1900 h to its three experiments (ASACUSA, ATHENA and ATRAP) with beam properties meeting, and often exceeding design specification. Stochastic cooling with cool-down times of 18 s works as aimed for in the design. Electron cooling using the “old LEAR cooler” reaches the very small equilibrium emittances required but still takes more time (12 s instead of 6 s anticipated in the 1996 design). However the increase in cycle length is made up for by the higher deceleration efficiency. ASACUSA has very successfully continued the program of antiprotonic helium 3 spectroscopy and ATHENA and ATRAP have reported last autumn the synthesis of copious numbers of cold antihydrogen atoms.