Advanced studies on the Polycapillary Optics use at XLab Frascati

X-ray analytical techniques are widely used in the world. By the way, due to the strong radiation-matter interaction, to design optical devices suitable for X-ray radiation remains still of wide interest. As a consequence of novel advanced material studies, in the last 30 years several typologies of X-ray lenses have been developed. In this work, a short review on the status of Polycapillary Optics (polyCO), from design and fabrication to various applications, has been presented making comparison of the results achieved by several groups through different X-ray optical elements. A focus is regarded for advanced X-ray imaging and spectroscopy tools based on combination of the modem polyCO hardware and the reconstruction software, available as homemade and commercially ones. Recent results (in three main fields, high resolution X-ray imaging, micro-XRF spectroscopy and micro-tomography) obtained at XLab Frascati have been discussed

Polycapillary optics for soft X-ray imaging and tomography

Magnetic plasmas are extended volumetric sources of X-rays, and these emissions could reveal a lot of information about the processes occurring into the plasmas. Unfortunately, the constraints posed by these toroidal devices (high neutron flux, gamma and hard-X background, extremely high radiofrequency powers, high magnetic fields, optical limitations and so on) are very severe and limit strongly the possibility to install X-ray detectors directly into or close to the machine. Soft X-ray diagnostics are meant both as tomography and imaging. We started, therefore, to investigate the feasibility of using polycapillary optics for these purposes, in collaboration between Istituto Nazionale di Fisica Nucleare (INFN)- Frascati, Ente per le Nuove tecnologie, l’Energia e l’Ambiente (ENEA)-Frascati and the Commissariat de l’Energie Atomique (CEA)-Cadarache. The first tests were performed in order to characterize the polycapillary lenses (convergence, divergence, efficiency, spectral dispersion, etc.) for distances much larger than the optical focal length of the lenses, both for the detector and for the source. A silicon-based C-MOS imager (Medipix 2) has been used as a detector and the micro focus X-ray tubes as point-like sources. Results of these preliminary tests are presented, and the imaging capabilities of a polycapillary lens as well

Polycapillary based μXRF station for 3D colour tomography

The “Rainbow X-Ray” (RXR) experimental station at XLab Frascati of the Frascati’s National Laboratories (LNF) INFN is a dedicated station for X-ray fluorescence studies based on the use of polycapillary lenses in a confocal geometry. The flexible RXR layout allows investigating specimens of the dimensions ranging from several millimeters up to half meter and weighting up to several tens of kilograms. Compared to similar existing XRF stations, apart of the possibility for investigating large samples, the main advantage of this equipment is the detection system with two spectrometers optimized to work separately at high and at low X-ray energie

Spectral structure of a polycapillary lens shaped X-ray beam

Polycapillary X-ray optics is widely used in X-ray analysis techniques to create a small secondary source, for instance, or to deliver X-rays to the point of interest with minimum intensity losses [1]. The main characteristics of the analytical devices on its base are the size and divergence of the focused or translated beam. In this work, we used the photon-counting pixel detector ModuPIX to study the parameters for polycapillary focused X-ray tube radiation as well as the energy and spatial dependences of radiation at the focus. We have characterized the high-speed spectral camera ModuPIX, which is a single Timepix device with a fast parallel readout allowing up to 850 frames per second with 256•256 pixels and a 55 [mu]m pitch defined by the frame frequency. By means of the silicon monochromator the energy response function is measured in clustering mode by the energy scan over total X-ray tube spectrum

Parametric X-Ray detection in UA9 experiment

Parametric X-Ray radiation (PXR) is a phenomenon due to the interaction of charged particles inside a crystal well ordered lattice. The passage of the particles inside the potential field into the crystal causes small deflections which result in radiation emissions. By this way the emission is diffracted by the crystal planes. In this work the results of the last five years of activity on PXR detection during UA9 experiment are reported. The beam provided in H8 area, protons or Pb ions, is channeled inside different crystals and PXR emission is detected

TM oxides coatings for high demanding accelerator components

Large electric gradients are required for a variety of new applications, notably including the extreme high brightness electron sources for X-ray free electron lasers (FELs), RF photoinjector, industrial and medical accelerators and linear accelerators for particle physics colliders. In the framework of a INFN-LNF, SLAC (USA), KEK (Japan), UCLA (Los Angeles) collaboration, the Laboratori Nazionali di Frascati (LNF) is involved in the modelling, development and test of RF structures devoted to acceleration with high gradient electric field of particles through metal device. In order to improve the maximum sustainable gradients in normal conducting RF accelerating structures, we had to minimize the breakdown and the dark current. To this purpose the study of new materials and manufacturing techniques is mandatory to identify solutions to such extremely demanding applications. We considered the possibility to coat copper (and other metals) with a relatively thick film to improve and optimize breakdown performances. We present here the first characterization of MoO3 films deposited on copper by pulsed-laser deposition (PLD) starting from a commercial MoO3 target

Test of candidate light distributors for the muon (g−-2) laser calibration system

The new muon (g-2) experiment E989 at Fermilab will be equipped with a laser calibration system for all the 1296 channels of the calorimeters. An integrating sphere and an alternative system based on an engineered diffuser have been considered as possible light distributors for the experiment. We present here a detailed comparison of the two based on temporal response, spatial uniformity, transmittance and time stability.Comment: accepted to Nucl.Instrum.Meth.

Interdisciplinary Medication Adherence Program: The Example of a University Community Pharmacy in Switzerland.

The Community Pharmacy of the Department of Ambulatory Care and Community Medicine (Policlinique Médicale Universitaire, PMU), University of Lausanne, developed and implemented an interdisciplinary medication adherence program. The program aims to support and reinforce medication adherence through a multifactorial and interdisciplinary intervention. Motivational interviewing is combined with medication adherence electronic monitors (MEMS, Aardex MWV) and a report to patient, physician, nurse, and other pharmacists. This program has become a routine activity and was extended for use with all chronic diseases. From 2004 to 2014, there were 819 patient inclusions, and 268 patients were in follow-up in 2014. This paper aims to present the organization and program's context, statistical data, published research, and future perspectives

Deep ice as a geochemical reactor: Insights from iron speciation and mineralogy of dust in the Talos Dome ice core (East Antarctica)

Thanks to its insolubility, mineral dust is considered a stable proxy in polar ice cores. With this study we show that the Talos Dome ice core (TALDICE, Ross Sea sector of East Antarctica) displays evident and progressive signs of post-depositional processes affecting the mineral dust record below 1000g m deep. We apply a suite of established and cutting-edge techniques to investigate the properties of dust in TALDICE, ranging from concentration and grain size to elemental composition and Fe mineralogy. Results show that through acidic/oxidative weathering, the conditions of deep ice at Talos Dome promote the dissolution of specific minerals and the englacial formation of others, affecting primitive dust features. The expulsion of acidic atmospheric species from ice grains and their concentration in localized environments is likely the main process responsible for englacial reactions. Deep ice can be seen as a "geochemical reactor"capable of fostering complex reactions which involve both soluble and insoluble impurities. Fe-bearing minerals can efficiently help in exploring such transformations