This volume contains the proceedings of the third Euroconference on Atomic Phys ics at Accelerators (APAC 2001), with the title Stored Particles and Fundamental Physics. It was held in Aarhus, Denmark, from September 8 to 13 at the Marselis Hotel located near the beach and the Marselis Woods outside Aarhus, but some of the activities took place at the Department of Physics, University of Aarhus. The conference was sponsored by the Commission of the European Union (Contract No. ERBFMMACT980469) and also by the Danish Research Foundation through ACAP (Aarhus Center for Atomic Physics). The meeting was focused on the application of storage rings for atomic physics, and there are two fairly small rings in Aarhus, ASTRID (Aarhus STorage Ring for Ions, Denmark) and ELISA (ELectrostatic Ion Storage ring, Aarhus). The research at these rings has contributed to the strong position of European Science in this field. Both rings are designed according to unique concepts. ASTRID is a dual purpose ring, which half the time stores electrons for the generation of low-energy synchrotron radiation. The storage of negative particles has also been a unique feature for the application of ASTRID as an ion storage ring."

The search for examples of proton radioactivity has resulted in the discovery of a large number of proton emitters in the region 50 < Z < 84 [1]. Many of these proton emitters and their daughters are also a-emitters, and in some cases the a-decay chain from the daughter terminates on a nuclide closer to stability whose mass excess is known. This opens up the possibility of using a-and proton-decay Q-values to determine the mass excesses of a large group of nuclei connected by particle decay. The Q-values are derived from the measured kinetic energies of the emitted protons or a-particles. Where the decay chains are not connected to nuclei with known mass excesses, proton separation energies can be measured in some cases and derived in others. For the a-decay ofthe parent nucleus (Z, A) to the daughter (Z - 2, A - 4), the energy and momentum relations used to convert between Q-value, mass (M) and mass excess (ME) are: M(4He)E", (1) M(Z - 2, A - 4)Erecoil, (2) Q", E", + Erecoi\, ME(Z, A) Q", + ME(Z - 2, A - 4) + ME(4He). (3) In practice, one uses M(4He) ~ 4 and M(Z - 2, A - 4) (A - 4), so that Equation (3) becomes ME(Z, A) = E", (_A_) + ME(Z - 2, A - 4) + ME(4He). (4) A -4 Similarly, for protons, we have ME(Z, A) = Ep(_A_) +ME(Z - 1, A-I) +ME(lH).

This volume contains the proceedings of the third Euroconference on Atomic Phys ics at Accelerators (APAC 2001), with the title Stored Particles and Fundamental Physics. It was held in Aarhus, Denmark, from September 8 to 13 at the Marselis Hotel located near the beach and the Marselis Woods outside Aarhus, but some of the activities took place at the Department of Physics, University of Aarhus. The conference was sponsored by the Commission of the European Union (Contract No. ERBFMMACT980469) and also by the Danish Research Foundation through ACAP (Aarhus Center for Atomic Physics). The meeting was focused on the application of storage rings for atomic physics, and there are two fairly small rings in Aarhus, ASTRID (Aarhus STorage Ring for Ions,Denmark) and ELISA (ELectrostatic Ion Storage ring, Aarhus). The research at these rings has contributed to the strong position of European Science in this field. Both rings are designed according to unique concepts. ASTRID is a dual purpose ring, which half the time stores electrons for the generation of low-energy synchrotron radiation. The storage of negative particles has also been a unique feature for the application of ASTRID as an ion storage ring.