[en] With respect to the other photoelectron microscopy techniques, a scanning photoemission microscope (SPEM) uses the direct approach to photoelectron spectromicroscopy, which is the use of a small focused photon probe to illuminate the surface. The SPEM at the Elettra synchrotron light source can operate in two modes: imaging and spectroscopy. In the first mode, the sample surface is mapped by synchronized scanning of the sample with respect to the focused photon beam and collecting photoelectrons with a selected kinetic energy. The second mode is photoelectron spectroscopy from a microspot. The well-known capabilities of photoemission to chemically probe the surface of conducting and semiconducting, and to a certain extent of insulating, materials can be exploited at a submicrometre level for the investigation of spatially heterogeneous or confined systems, structures measured in micro- or nanometres, etc. (author)

No abstract available

[en] Real-time dosimetry is a critical issue in most radiotherapy applications. SUCIMA (Proceedings of the Eighth Topical Seminar on Innovative Particle and Radiation Detectors, Siena, Italy) (Silicon Ultra fast Cameras for electron and gamma sources in Medical Applications) is an EC project addressing the development of an imaging device for extended radioactive sources based on monolithic and hybrid position sensitive silicon sensors. Preliminary results imaging ⁹⁰Sr and ¹⁴⁴Ce brachytherapy sources are presented. Large area Silicon strip detectors, read out by low noise charge integrating chips, have been used to measure the dose depth curve in a tissue equivalent material according to the prescription by American Association of Physicist in Medicine Task Group No. 60. Real-time measurements have been compared to the results obtained in the same geometry using GafChromic films

No abstract available

[en] A Dynamic High Pressure (DHP) system has been developed, tested and implemented in the scanning photoelectron microscope (SPEM) operated at ESCAmicroscopy beamline at Elettra synchrotron. The system consists of a compact gas injection set up that allows experiments with local pressure near the sample several orders of magnitude higher that the allowable pressure for X-ray photoelectron spectroscopy setups. The DHP setup controls the amount of gas injected toward the sample by fine tuning the time and spatial profiles using a pulsed valve and a nozzle, respectively. The DHP functionality and effectiveness has been demonstrated by in operando oxidation experiments of Ru and Si. The obtained results confirmed that using the DHP the gas exposure onto the sample is equivalent to a static pressure between 10⁻³ and 10⁻² mbar, about 3 orders of magnitude higher than the maximum gas pressure for the XPS machines under operation.

No abstract available

[en] X-rays are an excellent investigation tool in the field of cultural heritage, this is mainly due to their capability of yielding fine details about chemical and structural information of a sample without damaging its integrity [1-4]. Synchrotron Radiation (SR) sources offer additional advantages to the X-ray techniques carried out with laboratory sources: the tuneable photon energy and the high photon flux provided by synchrotrons allow one to optimise the sensitivity to a given element while pushing the detection limits down to the ppm range. These characteristics enable to detect and quantify trace elements in artefacts. From such quantification, insightful details on the materials employed in the fabrication and on the fabrication process itself can be obtained. In this work, four gold coins dated back to the Roman Empire (IV - V century) were studied with X-Ray Fluorescence (XRF) and X-ray Absorption Near Edge Spectroscopy (XANES), both carried out at XRF beamline, at Elettra Sincrotrone Trieste.

[en] Two novel pixel sensor concepts for future linear collider applications are presented in this paper: a hybrid pixel sensor characterized by a layout improving the single point resolution and a monolithic detector inspired by silicon on insulator (SOI) technology. The results of charge collection studies for the first prototypes of hybrid pixel sensors with interleaved pixels are reported and the new detector test structures are introduced. The technology and the readout architecture design for SOI sensors are also discussed

[en] The investigation of hydroxides and oxide of aluminium in rapidly solidified foils of Al and Al-Cr alloys has been performed by means of scanning photoelectron microscopy and X-ray powder diffraction. Synchrotron-based photoelectron microscopy was chosen as a powerful tool for comprehensive characterization of novel materials in imaging mode and micro-spectroscopy (μ-XPS) mode at selected locations of foil surface. In Al-Cr alloys, surface areas with increased and lowed chrome content were observed. The effect of chrome on aluminum oxidation is established. The areas enriched with chrome are characterized by prevalence of metallic component of Al2p μ-XPS spectra which corresponds to aluminium in metallic state. The areas which are impoverished by chrome are mainly composed of aluminum oxide and aluminium hydroxides such as gibbsite, diaspore and boehmite. (authors)

[en] The present study demonstrates the advances of using scanning photoelectron microscopy and imaging accomplished by RBS and AFM to investigate the surface segregation of alloying elements in RS aluminum. Depth profiling of elemental composition indicates that RS microstructure evolution is influenced by solute-nanostructured defect interactions in Al-Cr alloys. It was found that Cr 2p and 3p core level photoemission spectra exhibits foil surface impoverishment of chromium. In agreement with dope depth profiling as carried out by RBS, the revealed phenomenon can be attributed to the fact that Cr drastically reduces the concentration of vacancies compared with RS pure Al, and affects H behaviour in RS Al-Cr alloys. Obtained results indicate that the surface microstructure of the Al alloy foils at the sub-micrometer scale, as far as the high density of quenched-in vacancies is concerned, is essential to elucidate how the microstructural morphology resulting from rapid solidification affects hydrogen trapping at lattice defects. (authors)