A. N. Wilson

Single step links of the superdeformed band in Pb-194 : A measure of the absolute excitation energy, spin and parity of the superdeformed states

Abstract The EUROGAM array has been used to investigate the decay out of the yrast superdeformed (SD) band in 194 Pb. Six single step decays from the lowest observed SD states to low-lying states at normal deformation (ND) have been identified. From this observation, the excitation energy of the SD band in 194 Pb is established at 4877 ± 1.5 keV for the 6 + SD state. The most probable spins and parities of all members of the SD band are also deduced assuming that the SD states have even spin and positive parity.

Academics' perceptions of the purpose of undergraduate research experiences in a research-intensive degree

The inclusion of research experiences as core components of undergraduate curricula implies that students will be exposed to and situated within the research activities of their university. Such experiences thus provide a new prism through which to view the relations between teaching, research and learning. The intentions and actions of academics supervising these activities will be strongly influenced by their beliefs regarding the nature of research, and the relation between research and learning in the undergraduate context. Surveys of academics supervising such experiences reveal a range of intentions, only some of which address the higher order and critical thinking skills associated with research or independent learning. This may indicate a lack of deep reflection on the purpose of exposing undergraduates to research, but may also be due to the predominance of a hierarchical view of the process by which one makes the transition from student to researcher.

'Please remember we are not all brilliant':undergraduates' experiences of an elite, research-intensive degree at a research-intensive university

Undergraduate research experiences are being incorporated into degree programs with increasing frequency. However, there has been little study into their effectiveness in preparing students for research or into the learning gains that students realise from one or more research experiences. We surveyed science students in an elite, research‐based undergraduate degree program at a research‐intensive university. These students complete six research projects during their degree and we aimed to delineate factors that students perceive as leading to either good or bad experiences. Two factors stand out as contributing to a successful research experience: the supervisor, with students reporting both pedagogic and affective benefits of good supervision; and the feeling that they are doing authentic science. Surprisingly, given the research‐intensive nature of this degree, the learning gains students report relate to both an appreciation of what research is like and life skills, such as time management, rather than scientific thinking skills.

Probing Shell Structure and Shape Changes in Neutron-Rich Sulfur Isotopes through Transient-Field g-Factor Measurements on Fast Radioactive Beams of 38S and 40S

The shell structure underlying shape changes in neutron-rich nuclei near N = 28 has been investigated by a novel application of the transient-field technique to measure the first-excited-state g factors in 38S and 40S produced as fast radioactive beams. There is a fine balance between proton and neutron contributions to the magnetic moments in both nuclei. The g factor of deformed 40S does not resemble that of a conventional collective nucleus because spin contributions are more important than usual.

Measured g factors and the tidal-wave description of transitional nuclei near A=100

The transient-field technique has been used in both conventional kinematics and inverse kinematics to measure the g factors of the 2{sub 1}{sup +} states in the stable even isotopes of Ru, Pd, and Cd. The statistical precision of the g(2{sub 1}{sup +}) values has been significantly improved, allowing a critical comparison with the tidal-wave version of the cranking model recently proposed for transitional nuclei in this region.

Revisiting "Is the scientific paper a fraud?": The way textbooks and scientific research articles are being used to teach undergraduate students could convey a misleading image of scientific research.

In 1963, Peter Medawar gave a talk, Is the scientific paper a fraud? , in which he argued that scientific journal articles give a false impression of the real process of scientific discovery [1]. In answering his question, he argued that, “The scientific paper in its orthodox form does embody a totally mistaken conception, even a travesty, of the nature of scientific thought.” His main concern was that the highly formalized structure gives only a sanitized version of how scientists come to a conclusion and that it leaves no room for authors to discuss the thought processes that led to the experiments. Medawar explained that papers were presented to appear as if the scientists had no pre‐conceived expectations about the outcome and that they followed an inductive process in a logical fashion. In fact, scientists do have expectations and their observations and analysis are made in light of those expectations. Although todays scientific papers are increasingly presented as being hypothesis‐driven, the underlying thought processes remain hidden; scientists appear to follow a logical and deductive process to test their idea and the results of these tests lead them to support or reject the hypothesis. However, even the trend toward more explicit framing of a hypothesis is often misleading, as hypotheses may be framed to explain a set of observations post hoc , suggesting a linear process that does not describe the actual discovery. There is, of course, a good reason why the scientific paper is highly formalized and structured. Its purpose is to communicate a finding and it is important to do this as clearly as possible. Even if the actual process of discovery had been messy, a good paper presents a logical argument, provides supporting evidence, and comes to a conclusion. The reader usually does not need or …

Magnetic rotation in 197Pb and 198Pb

Abstract High-spin states in 197Pb and 198Pb were populated in the 186W(18O ,x n) reactions. In-beam γ -ray coincidences were measured in two experiments using the Gammasphere and the Eurogam II spectrometer arrays, respectively. In both nuclei new bands of enhanced magnetic dipole transitions were found and the known cascades were partly reordered and extended to higher spins. In most cases, γ -ray transitions connecting the magnetic rotational bands to lower-lying states have been identified. Configuration assignments are suggested for the bands. The systematic behavior confirms the shears mechanism. An effective interaction between the main high-spin proton and neutron orbitals is derived.

Shell structure underlying the evolution of quadrupole collectivity in 38 S and 40 S probed by transient-field g-factor measurements on fast radioactive beams

The shell structure underlying shape changes in neutron-rich nuclei between N=20 and N=28 has been investigated by a novel application of the transient field technique to measure the first-excited state g factors in {sup 38}S and {sup 40}S produced as fast radioactive beams. Details of the new methodology are presented. In both {sup 38}S and {sup 40}S there is a fine balance between the proton and neutron contributions to the magnetic moments. Shell-model calculations that describe the level schemes and quadrupole properties of these nuclei also give a satisfactory explanation of the g factors. In {sup 38}S the g factor is extremely sensitive to the occupation of the neutron p{sub 3/2} orbit above the N=28 shell gap as occupation of this orbit strongly affects the proton configuration. The g factor of deformed {sup 40}S does not resemble that of a conventional collective nucleus because spin contributions are more important than usual.

Shape coexistence at high spin in the N = Z+2 nucleus Se-70

The nucleus Se-70 was studied using the Ca-40(Ca-40, 2alpha2p) reaction at a beam energy of 185 MeV. Gamma rays were measured with the EUROBALL III spectrometer. The known positive-parity bands have been extended and one new band of positive parity and two of negative parity have been identified. These bands are interpreted in terms of the cranked Nilsson-Strutinsky approach. Calculations suggest that the two negative-parity bands, which have the same signature, are both based on a configuration with two protons and three neutrons lifted from the fp shell to the g(9/2) orbital, but at different nuclear shapes. This represents a shape coexistence at high spin.

Very high rotational frequencies and band termination in 73Br

Rotational bands in