Presented is a novel high sensitivity magnetometer allowing us to measure the magnetization reversal of about 104 μB corresponding to a sensitivity of about 10−16 emu. The detector is a niobium micro-bridge DC superconducting quantum interference device (SQUID), fabricated using electron-beam lithography. It is operational in the temperature range of 0–7 K. Furthermore, we present a method to deposit on the SQUID loop a small number of Co clusters of about 2–5 nm in diameter. The first results obtained on these samples show that there is still a ferromagnetic coupling between the clusters and the magnetization reversal takes place by small avalanches.
The Multi Unit Spectroscopic Explorer (MUSE) is a second-generation VLT panoramic integral-field spectrograph under preliminary design study.MUSE has a field of 1x1 arcmin² sampled at 0.2x0.2arcsec² and is assisted by the VLT ground layer adaptive optics ESO facility using four laser guide stars.The simultaneous spectral range is 0.465-0.93µm, at a resolution of R~3000.MUSE couples the discovery potential of a large imaging device to the measuring capabilities of a high-quality spectrograph, while taking advantage of the increased spatial resolution provided by adaptive optics.This makes MUSE a unique and tremendously powerful instrument for discovering and characterizing objects that lie beyond the reach of even the deepest imaging surveys.MUSE has also a high spatial resolution mode with 7.5x7.5 arcsec² field of view sampled at 25 milli-arcsec.In this mode MUSE should be able to obtain diffraction limited data-cubes in the 0.6-0.93 µm wavelength range.Although the MUSE design has been optimized for the study of galaxy formation and evolution, it has a wide range of possible applications; e.g.monitoring of outer planets atmosphere, environment of young stellar objects, super massive black holes and active nuclei in nearby galaxies or massive spectroscopic surveys of stellar fields in the Milky Way and nearby galaxies.
Abstract Rutile single crystals (TiO2) have been implanted with heavy metallic particles in the energy range 0.3 MeV, 56 MeV. Optical measurements have been performed during implantation. Conductivity and Rutherford backscattering measurements have been made on as-implanted samples and after thermal treatments. With alkali ions implanted in TiO2 the optical spectra exhibit an absorption band associated with a transition of titanium 3+ state after irradiation. The conductivity of the implanted layer increases by a factor of the order of 107 after implantation with a dose of 1017 particles per cm2. Thermal treatments of these samples do not permit to obtain metallic absorption of alkali aggregates like in magnesium oxide. These results confirm the hypothesis of chemical bonding between alkali ions and oxygen correlated to the formation of Ti3+. With noble metal ions, like silver or gold implanted in TiO2, the optical spectra exhibit optical absorption of small metallic aggregates of silver or gold. The absorption band positions correspond to theoretical absorption of silver or gold colloids in rutile. Thermal treatments permit to increase the precipitation process. Two kinds of behaviour occur in implanted rutile, with metallic ions depending on the electronegativity of implanted particles. When it is lower than titanium electronegativity a chemical bond is obtained between implanted particles and oxygen correlated to Ti3+ formation, then when it is higher, aggregates of implanted particles are obtained.
