Simulation and experimental qualification of the response of microstrip detectors to ion beams
In the framework of the construction of a novel Femtoscope Array for Correlation and Spectroscopy, named FARCOS, aiming at the identification in charge and mass even of particles stopping in the first detection layer, we are performing a thorough characterization of the silicon detector layers in terms of the collection properties as a function of the point of incidence. We have experimental evidence - as previously observed also in the literature for other strip detectors - that interstrip incidence alters the signal shape not only for the trivial effect of charge sharing but also because of induction effects on neighbor strips. In order to clarify this issue we developed a custom simulation suite of the electron-hole transport and signal formation able to properly describe 3-D Coulomb interaction and thermal diffusion in semiconductor detectors. We ran a batch of significant and representative simulations presenting the qualitative correct interpretation and the quantitative validation as proved by the comparison of the simulation results with the experimental data.
MUST2: A new generation array for direct reaction studies
Abstract.We have developed a new telescope array, dedicated to the study of direct reactions of exotic nuclei on light targets in inverse kinematics. This device, called MUST2, is briefly described, and the results of the first tests performed with an alpha source and Ni beams at 10 and 75 MeV/u on a CDH target are presented.
Imaging the in-plane magnetization in a Co microstructure by Fourier transform holography.
We report on experiments using Fourier transform holography to image the in-plane magnetization of a magnetic microstructure. Magnetic sensitivity is achieved via the x-ray magnetic circular dichroism effect by recording holograms in transmission at off-normal incidence. The reference beam is defined by a narrow hole milled at an inclined angle into the opaque mask. We present magnetic domain images of an in-plane magnetized cobalt element with a size of 2 μm × 2 μm× 20 nm. The domain pattern shows a multi-vortex state that deviates from the simple Landau ground state.