An ultrasonic system for intravascular measurement and visualisation of anatomical structures and blood flow

Imperial Users onl

Interpretation of the large-deformation high-spin bands in select A=158-168 nuclei

The high-spin rotational bands in Hf-168 and the triaxial bands in Lu nuclei are analyzed using the configuration-constrained cranked Nilsson-Strutinsky (CNS) model. Special attention is given to the up-sloping extruder orbitals. The relative alignment between the bands which appear to correspond to triaxial shape is also considered, including the yrast ultrahigh-spin band in Er-158. This comparison suggests that the latter band is formed from rotation around the intermediate axis. In addition, the standard approximations of the CNS approach are investigated, indicating that the errors which are introduced by the neglect of off-shell matrix elements and the cutoff at nine oscillator shells (N-max = 8) are essentially negligible compared to other uncertainties. On the other hand, the full inclusion of the hexadecapole degree of freedom is more significant; for example it leads to a decrease of the total energy of similar to 500 keV in the triaxial superdeformed (TSD) region of Hf-168

Internal dose assessment for environmental monitoring in nuclear power plant accidents

A method for exploiting human's internal contamination data for radioactive release estimation in nuclear power plant accidents is proposed. Nevertheless, such data is often very rough and uncertain; it is accessible even in toughest situations when most of the active and passive monitors are damaged by the accident. These data can be used in combination with other collectable data for estimating the event scale in severe nuclear power plan accidents. The rationale behind the method is that nuclear power plant accidents are often associated with internal contamination of radiation workers involved in the early stages of emergency response activities mainly due to the release of 131I in atmosphere. The proposed inverse analytical approach uses the 131I intake of contaminated workers, their working conditions, chronology of events, and applied personal safety measures during the first hours or days of the emergency response activities to estimate the magnitude of 131I concentration in the air

The Λp\bf{\Lambda p} interaction studied via femtoscopy in p + Nb reactions at sNN=3.18 GeV\mathbf{\sqrt{s_{NN}}=3.18} ~\mathrm{\bf{GeV}}

We report on the first measurement of $p\Lambda$ and $pp$ correlations via the femtoscopy method in p+Nb reactions at $\mathrm{\sqrt{s_{NN}}=3.18} ~\mathrm{GeV}$, studied with the High Acceptance Di-Electron Spectrometer (HADES). By comparing the experimental correlation function to model calculations, a source size for $pp$ pairs of $r_{0,pp}=2.02 \pm 0.01(\mathrm{stat})^{+0.11}_{-0.12} (\mathrm{sys}) ~\mathrm{fm}$ and a slightly smaller value for $p\Lambda$ of $r_{0,\Lambda p}=1.62 \pm 0.02(\mathrm{stat})^{+0.19}_{-0.08}(\mathrm{sys}) ~\mathrm{fm}$ is extracted. Using the geometrical extent of the particle emitting region, determined experimentally with $pp$ correlations as reference together with a source function from a transport model, it is possible to study different sets of scattering parameters. The $p\Lambda$ correlation is proven sensitive to predicted scattering length values from chiral effective field theory. We demonstrate that the femtoscopy technique can be used as valid alternative to the analysis of scattering data to study the hyperon-nucleon interaction.Comment: 12 pages, 11 figure

Verification of electromagnetic calorimeter concept for the HADES spectrometer

The HADES spectrometer currently operating on the beam of SIS18 accelerator in GSI will be moved to a new position in the CBM cave of the future FAIR complex. Electromagnetic calorimeter (ECAL) will enable the HADES@FAIR experiment to measure data on neutral meson production in heavy ion collisions at the energy range of 2-10 A GeVon the beam of the new accelerator SIS100. Calorimeter will be based on 978 massive lead glass modules read out by photomultipliers and a novel front-end electronics. Secondary gamma beam with energies ranging from 81 MeV up to 1399 MeV from MAMI-C Mainz facility was used to verify selected technical solutions. Relative energy resolution was measured using modules with three different types of photomultipliers. Two types of developed front-end electronics as well as energy leakage between neighbouring modules under parallel and declined gamma beams were studied in detail