The overall performance of the MAMMI reported on this evaluation quantifies its ability to produce high quality PET images. Spatial resolution values below 3 mm were measured in most of the FOV. Only the radial component of spatial resolution exceeds the 3 mm at radial positions larger than 60 mm. This study emphasizes the need for standardized testing methodologies for dedicated breast PET systems similar to NEMA standards for whole-body and small animal PET scanners.

The feeding probability of 102;104;105;106;107 Tc, 105 Mo, and 101 Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the component of the decay heat for 239 Pu in the 4-3000 s range. DOI: 10.1103/PhysRevLett.105.202501 PACS numbers: 23.40.Às, 27.60.+j, 28.41.Fr, 29.30.Kv Nuclear reactors provide a significant fraction of the world's electricity. A burgeoning population and an associated growth in economic activity suggest that world demand will double by 2050. Until now, the bulk of this has come from the burning of fossil fuels. There is general concern that reserves of fossil fuels are limited and their burning damages the environment. In particular, it contributes to the emission of large amounts of CO 2 . In this context, nuclear power, based on the fission process, will be less damaging to the environment. Accordingly there is now a renaissance in the building of nuclear power stations around the world. Modern reactor designs, based on many years of operating experience, are much more efficient, more economical, and safer than earlier designs. Although the basic principles are well established, we still lack certain information, such as a knowledge of the decay properties of specific nuclei that are important contributors to the heating of the reactor during and after operation. The estimation and control of the heat emitted by the decay of fission products plays a key role in the safe operation of reactors. The primary aim of this work is to study the decay properties of specific nuclei that are important contributors to this source of heat.Approximately 8% of the total energy generated during the fission process is related to the energy released in the natural decay of fission products, and is commonly called decay heat [1]. Once the reactor is shut down, the energy released in radioactive decay provides the main source of heating. Hence, coolant needs to be maintained after termination of the neutron-induced fission process in a reactor, and the form and extent of this essential requirement needs to be specified on the basis of decay-heat summation calculations. Decay heat varies as a function of time after shutdown and can be determined theoretically from known nuclear data. Such computations are based on the inventory of nuclei created during the fission process and after reactor shutdown and their radioactive decay characteristics:where fðtÞ is the power function, E i is the mean decay energy of the ith nuclide ( , , and components), i is the decay constant of the ith nuclide, and N i ðtÞ is the number of nuclide i at cooling time t. These calculations require extensive libraries of cross sections, fission yields, and decay data. Obviously, an accurate assessment of the decay heat is highly relevant...

The transfer of neutrons onto 24 Ne has been measured using a reaccelerated radioactive beam of 24 Ne to study the ðd; pÞ reaction in inverse kinematics. The unusual raising of the first 3=2 þ level in 25 Ne and its significance in terms of the migration of the neutron magic number from N ¼ 20 to N ¼ 16 is put on a firm footing by confirmation of this state's identity. The raised 3=2 þ level is observed simultaneously with the intruder negative parity 7=2 À and 3=2 À levels, providing evidence for the reduction in the N ¼ 20 gap. The coincident gamma-ray decays allowed the assignment of spins as well as the transferred orbital angular momentum. The excitation energy of the 3=2 þ state shows that the established USD shell model breaks down well within the sd model space and requires a revised treatment of the proton-neutron monopole interaction. DOI: 10.1103/PhysRevLett.104.192501 PACS numbers: 21.10.Hw, 21.10.Jx, 23.20.Lv, 25.60.Je The monopole part of the nucleon-nucleon interaction is now recognized as having a major effect on nuclear shell structure far from stability [1,2]. The interaction between valence protons and neutrons is sufficient to alter the energies of single-particle levels so that different magic numbers (or shell gaps) appear, and this can substantially affect the collective [3] and magnetic [4] properties and basic quantities such as the lifetime [5]. Nucleon transfer reactions induced by light ions are an established experimental tool for studying single-particle structure [6]. Here we employ the ðd; pÞ reaction in inverse kinematics to explore the disappearance of the N ¼ 20 magic number (and its replacement by N ¼ 16) in the neutron-rich neon isotones. As will be shown, the measurement of the differential cross sections of the light ejectiles plus the coincident gamma decays of the residual nucleus brings a new power to this type of study.Recent work using other techniques has provided evidence for the emergence of N ¼ 16 as a magic number in this region, but has not identified the single-particle structure in an unambiguous manner through measurements of the spectroscopic factors and spins. In a study of the decay of 25 F [7] the increased energy of the 0d 3=2 neutron orbital was inferred. This made use of a preliminary analysis of the present work [8] and concluded that the energy shift was consistent with the monopole effect [7]. In a study of 27 Ne using the ðd; pÞ reaction but without detecting the protons [9], a reduced gap between the 0d 3=2 and higher negative parity orbitals was deduced. This agreed with nucleon removal studies [10]. Finally, in recent studies of 23 O by transfer [11] and 25 O by proton removal [12] the 0d 3=2 state was found to have an increased excitation energy, but the required modifications to the shell-model interaction were not mutually consistent [11,12]. While an extensive review including the emergence of the N ¼ 16 magic number has recently been published [2], further quantitative data are needed in order to understand this monopole effect properly....

i-TED consists of both a total energy detector and a Compton camera primarily intended for the measurement of neutron capture cross sections by means of the simultaneous combination of neutron time-of-flight (TOF) and γray imaging techniques. TOF allows one to obtain a neutron-energy differential capture yield, whereas the imaging capability is intended for the discrimination of radiative background sources, that have a spatial origin different from that of the capture sample under investigation. A distinctive feature of i-TED is the embedded Dynamic Electronic Collimation (DEC) concept, which allows for a trade-off between efficiency and image resolution. Here we report on some general design considerations and first performance characterization measurements made with an i-TED demonstrator in order to explore its γ-ray detection and imaging capabilities.