Performance of the diamond active target prototype for the PADME experiment at the DAΦ\PhiNE BTF

The PADME experiment at the DA$\Phi$NE Beam-Test Facility (BTF) is designed to search for the gauge boson of a new $\rm U(1)$ interaction in the process e$^+$e$^-\rightarrow\gamma$+$\rm A'$, using the intense positron beam hitting a light target. The $\rm A'$, usually referred as dark photon, is assumed to decay into invisible particles of a secluded sector and it can be observed by searching for an anomalous peak in the spectrum of the missing mass measured in events with a single photon in the final state. The measurement requires the determination of the 4-momentum of the recoil photon, performed by a homogeneous, highly segmented BGO crystals calorimeter. A significant improvement of the missing mass resolution is possible using an active target capable to determine the average position of the positron bunch with a resolution of less than 1 mm. This report presents the performance of a real size $\rm (2x2 cm^2)$ PADME active target made of a thin (50 $\mu$m) diamond sensor, with graphitic strips produced via laser irradiation on both sides. The measurements are based on data collected in a beam test at the BTF in November 2015.Comment: 7 pages, 10 figure

Advances in Materials and Technologies for Gas Sensing from Environmental and Food Monitoring to Breath Analysis

Gas sensing research experiences a worldwide revival in the last years. From one side, the emergence of novel sensing materials enables unprecedented capacities for improving the device performances. From the other, the increasing opportunities for applications impacting current societal priorities highly motivate further studies. Here, this field is reviewed with special attention to the emerging approaches and the most recent breakthroughs, challenges, and perspectives. In particular, this study focuses on: 1) the sensing layers analyzing recent trends toward nanostructured, low-dimensional and composite materials; and 2) the latest achievements and targets in terms of applications, from environmental monitoring to food aroma identification and quality control up to the healthcare sector with breath analysis and diseases diagnosis

Study of a metal-halide perovskite CsPbBr3 thin film deposited on a 10B layer for neutron detection

Metal halide perovskite materials have received significant attention in recent years due to their promising properties and potential applications, particularly their use as scintillator detectors, which is rapidly emerging due to their promising advantages as detectors, such as low costs, fast response, high quantum yield, strong absorption, scalability, flexibility, and emission wavelength tunability. Given the effectiveness of perovskites as α particle detectors and the potential of 10B as a neutron converter, in this paper a 10B converting layer was coupled with an all-inorganic lead halide perovskite (CsPbBr3) layer aiming to create a thermal neutron detector. Specifically, a 1 μm thin film of 10B and a 1 μm thin layer of CsPbBr3 were deposited on a suitable substrate using a laser ablation process. The fabricated detector was subjected to a comprehensive characterization, including structural, morphological, and detection properties. As output, the films exhibit macroscopically uniform behavior and good adhesion to the substrate. In terms of thermal neutron efficiency, an efficiency of (7.9 ± 0.3)% was determined with respect to a commercial detector (EJ-426), which corresponds to an intrinsic efficiency of (2.5 ± 0.1)%. Also, Monte Carlo simulations were conducted, and the optimum value of the 10B layer thickness was found to be 2.5 μm

The Encapsulation of Citicoline within Solid Lipid Nanoparticles Enhances Its Capability to Counteract the 6-Hydroxydopamine-Induced Cytotoxicity in Human Neuroblastoma SH-SY5Y Cells

(1) Backgrond: Considering the positive effects of citicoline (CIT) in the management of some neurodegenerative diseases, the aim of this work was to develop CIT-Loaded Solid Lipid Nanoparticles (CIT-SLNs) for enhancing the therapeutic use of CIT in parkinsonian syndrome; (2) Methods: CIT-SLNs were prepared by the melt homogenization method using the self-emulsifying lipid Gelucire® 50/13 as lipid matrix. Solid-state features on CIT-SLNs were obtained with FT-IR, thermal analysis (DSC) and X-ray powder diffraction (XRPD) studies. (3) Results: CIT-SLNs showed a mean diameter of 201 nm, −2.20 mV as zeta potential and a high percentage of entrapped CIT. DSC and XRPD analyses evidenced a greater amorphous state of CIT in CIT-SLNs. On confocal microscopy, fluorescent SLNs replacing unlabeled CIT-SLNs released the dye selectively in the cytoplasm. Biological evaluation showed that pre-treatment of SH-SY5Y dopaminergic cells with CIT-SLNs (50 µM) before the addition of 40 µM 6-hydroxydopamine (6-OHDA) to mimic Parkinson’s disease’s degenerative pathways counteracts the cytotoxic effects induced by the neurotoxin, increasing cell viability with the consistent maintenance of both nuclear and cell morphology. In contrast, pre-treatment with CIT 50 and 60 µM or plain SLNs for 2 h followed by 6-OHDA (40 µM) did not significantly influence cell viability. (4) Conclusions: These data suggest an enhanced protection exerted by CIT-SLNs with respect to free CIT and prompt further investigation of possible molecular mechanisms that underlie this difference

The right to food and food diversity in the Italian Constitution

Il contributo analizza la tutela apprestata dalla Costituzione italiana al diritto al cibo che, pur non essendo espressamente menzionato, viene ricavato attraverso l'analisi di principi ed azioni sottese alla nostra Carta che ne riconoscono il valore: il principio lavorista, la lotta alla povertà, la retribuzione del lavoratore...

Detector Array Readout with Traveling Wave Amplifiers

Reducing noise to the quantum limit over a large bandwidth is a fundamental requirement for future applications operating at millikelvin temperatures, such as the neutrino mass measurement, the next-generation X-ray observatory, the CMB measurement, the dark matter and axion detection, and the rapid high-fidelity readout of superconducting qubits. The read out sensitivity of arrays of microcalorimeter detectors, resonant axion-detectors, and qubits, is currently limited by the noise temperature and bandwidth of the cryogenic amplifers. The Detector Array Readout with Traveling Wave Amplifers project has the goal of developing high-performing innovative traveling wave parametric amplifers with a high gain, a high saturation power, and a quantum-limited or nearly quantum-limited noise. The practical development follows two diferent promising approaches, one based on the Josephson junctions and the other one based on the kinetic inductance of a high-resistivity superconductor. In this contribution, we present the aims of the project, the adopted design solutions and preliminary results from simulations and measurements

Bimodal Approach for Noise Figures of Merit Evaluation in Quantum-Limited Josephson Traveling Wave Parametric Amplifiers

The advent of ultra-low noise microwave amplifiers revolutionized several research fields demanding quantum-limited technologies. Exploiting a theoretical bimodal description of a linear phase-preserving amplifier, in this contribution we analyze some of the intrinsic properties of a model architecture (i.e., an rf-SQUID based Josephson Traveling Wave Parametric Amplifier) in terms of amplification and noise generation for key case study input states (Fock and coherents). Furthermore, we present an analysis of the output signals generated by the parametric amplification mechanism when thermal noise fluctuations feed the device.Comment: 5 pages, 6 figure

Progress in the development of a KITWPA for the DARTWARS project

DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS) is a three years project that aims to develop high-performing innovative Traveling Wave Parametric Amplifiers (TWPAs) for low temperature detectors and qubit readout (C-band). The practical development follows two different promising approaches, one based on the Josephson junctions (TWJPA) and the other one based on the kinetic inductance of a high-resistivity superconductor (KITWPA). This paper presents the advancements made by the DARTWARS collaboration to produce a first working prototype of a KITWPA.Comment: 3 pages, 4 figures. Proceeding of Pisa15th Meeting conferenc

Diamond graphitization by laser-writing for all-carbon detector applications

The surface of a detector grade CVD polycrystalline diamond sample (5 × 5 × 0.05 mm3) was irradiated by an ArF excimer laser (λ = 193 nm, τ = 20 ns) to produce graphitic conductive layers. In particular, two sets of four parallel graphitic strip-like contacts, with 1 mm pitch, were created along the whole sample on the top and on the rear surfaces of the sample respectively. The two series of stripes lie normally to each other. Such a grid allows to obtain a segmented all-carbon device capable of giving bi-dimensional information on particle detection processes in nuclear applications. Afterwards, an extensive characterization of the samples was performed: SEM and micro-Raman investigations to study the morphological and structural evolution of the irradiated areas, EDS measurements to individuate any absorption phenomena from environment associated to laser treatment, and nanoindentation mapping to understand how the hard-soft transformation occurred depending on the locally transferred energy. Finally, current-voltage analyses were carried out checking the ohmic behavior of the diamond-graphite contact. By comparing the results of the different characterization analyses, a strong periodicity of the modified surface properties was found, confirming the reliability and reproducibility of the laser-induced graphitization process. The results demonstrate that the laser-writing technique is a good and fast solution to produce graphitic contacts on diamond surface and therefore represents a promising way to fabricate segmented all-carbon devices

Fabrication of a hydrogenated amorphous silicon detector in 3-d geometry and preliminary test on planar prototypes

Hydrogenated amorphous silicon (a-Si:H) can be produced by plasma-enhanced chemical vapor deposition (PECVD) of SiH4 (silane) mixed with hydrogen. The resulting material shows outstanding radiation hardness properties and can be deposited on a wide variety of substrates. Devices employing a-Si:H technologies have been used to detect many different kinds of radiation, namely, minimum ionizing particles (MIPs), X-rays, neutrons, and ions, as well as low-energy protons and alphas. However, the detection of MIPs using planar a-Si:H diodes has proven difficult due to their unsatisfactory S/N ratio arising from a combination of high leakage current, high capacitance, and limited charge collection efficiency (50% at best for a 30 µm planar diode). To overcome these limitations, the 3D-SiAm collaboration proposes employing a 3D detector geometry. The use of vertical electrodes allows for a small collection distance to be maintained while preserving a large detector thickness for charge generation. The depletion voltage in this configuration can be kept below 400 V with a consequent reduction in the leakage current. In this paper, following a detailed description of the fabrication process, the results of the tests performed on the planar p-i-n structures made with ion implantation of the dopants and with carrier selective contacts are illustrated