RESUMO
The Extremely Brilliant Source (EBS) is the experimental implementation of the novel Hybrid Multi Bend Achromat (HMBA) storage ring magnetic lattice concept, which has been realised at European Synchrotron Radiation Facility. We present its successful commissioning and first operation. We highlight the strengths of the HMBA design and compare them to the previous designs, on which most operational synchrotron X-ray sources are based. We report on the EBS storage ring's significantly improved horizontal electron beam emittance and other key beam parameters. EBS extends the reach of synchrotron X-ray science confirming the HMBA concept for future facility upgrades and new constructions.
RESUMO
Nuclear magnetic resonance (NMR) measurements in grossly inhomogeneous static magnetic fields are possible if the inhomogeneity is inferior to a theoretical limit. A design is proposed for a single-sided inside-out NMR probe with static and radiofrequency (RF) magnetic fields perpendicular and correlated on a large volume. This probe was constructed with ferrite material. It can found application as a portable scanner for local NMR spectrometry.
Assuntos
Desenho Assistido por Computador , Espectroscopia de Ressonância Magnética/instrumentação , Magnetismo/instrumentação , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Espectroscopia de Ressonância Magnética/métodos , Miniaturização , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Parallel Magnetic Resonance Imaging (MRI) methods employ receiver coils sensitivities to reduce imaging time: reconstruction algorithms need RF field maps which must be measured or estimated. Assuming statistical independence of different regions in a MR image, we consider the sensitivity estimation as a Blind Source Separation (BSS) problem that can be solved with Independent Component Analysis (ICA). This new formulation permits sensitivity maps extraction from only one MR acquisition, without calibration step or acquisition of additional k-space lines. Simulation results are presented for sensitivity encoded (SENSE) MR images, proving that sensitivity data can be extracted from statistical properties of the image, using the method ICASENSE.