Efficient accumulation of antiprotons and positrons, production of slow mono-energetic beams, and their applications

Recent progress of ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) project, particularly the antiproton trapping and slow antiproton production, is discussed. An RFQD (Radio Frequency Quadrupole Decelerator) installed in the ASACUSA beam line has an excellent deceleration efficiency of 25% providing 10-130keV antiprotons, which improves the final accumulation efficiency at least one and half orders of magnitude. The decelerated antiprotons are then injected in a large volume multiring trap, stored, and electron-cooled. About 1 million antiprotons are successfully accumulated per one AD shot and 10-500eV antiprotons are extracted as a mono-energetic beam. A UHV compatible positron accumulation is newly developed combining electron plasma and an ion cloud, which yields an accumulation rate as high as 400e+/s/mCi, two and a half orders of magnitude higher than other UHV compatible schemes. A new scheme to synthesize a spin-polarized antihydrogen beam is also discussed, which will play a vital role in determining the magnetic moment of antiproton with high precision. (orig.)