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Sea state affects the coasts of all maritime regions, and it impacts anthropic infrastructures and influences the activities carried out in the sea as well as in its proximity. Sea-state monitoring is therefore important for a number of reasons, including the need to validate weather forecast models and study the impact of sea waves on anthropic infrastructures such as ports. In this letter, we combined the measurements of sea state collected with Ocean Seismic Integrated System (OS-IS), a seismic-based system developed by AGI (Assist in Gravitation and Instrumentation) srl and INGV (National Institute for Geophysics and Volcanology), with those obtained using a Wave Radar system. The aim was to prove that this combination could enhance the efficacy and reliability of sea monitoring, thanks to the complementarity of the two types of measurements in terms of area covered and spatial resolution. More specifically, the sea-state parameters provided by OS-IS were compared with those provided by a Wave Radar system. OS-IS data were collected from three microseismic stations installed near the Gulf of La Spezia, on the Ligurian Coast, whereas the Wave Radar system was installed at the center of the Cinque Terre National Park at about 12 km from the OS-IS system. The comparison between the measurements of significant wave height (Hs) and peak period (Tp) showed a good agreement, with a correlation index close to 0.9. The residual difference highlights the complementarity of the two systems and the potential of an integrated system that includes both. In particular, OS-IS provides measurements over large, offshore areas, whereas the Wave Radar System provides high spatial-resolution measurements over areas near the coast.

Rotary encoders are used in many applications that require monitoring or controlling mechanical systems such as robots. Typically, small rotary encoders have poor resolution; this is unfortunate for applications such as robotics in medical surgery procedures. For example, in an articulated robotic endoscope, miniaturization is mandatory and, when automation is desired, high accuracy to track the shape and pose of the device is required; small (few millimeters) and accurate (few hundred arcsec) rotary encoders are thus needed. Previously, we introduced a novel concept of a miniaturizable angular sensor, called ASTRAS (Angular Sensor for TRAcking System). This was presented as a basic element of a tracking system for articulated endoscopes. The principle of measurement of ASTRAS is based on processing a shadow image cast by a shadow mask onto an image sensor. The characterization of the first prototype of ASTRAS was very promising, however, its angular range of about ±30 degrees was too limiting for many practical applications. In this work, we present an extension of the concept mentioned above to a rotary encoder that can measure one full rotation of 360 degrees thus the name is ASTRAS360. Its working principle bases on encoding the shadow image using colored light to distinguish different angular sectors. The identification of the sector corresponds to a coarse angular measurement, which is afterward refined using the same technique as in ASTRAS. We implemented this concept, realizing a prototype and an algorithm to calculate the angle from the shadow image. The experiments demonstrated the validity of this concept and showed encouraging results with a precision of ∼0.6 arcsec and 6σ-resolution of 3.6 arcsec corresponding to 19 bits., Sensors and Actuators A: Physical, 312, ISSN:0924-4247, ISSN:1873-3069

Robot-assisted and computer-guided minimally-invasive procedures represent a turning point in Minimally-Invasive Surgery (MIS) because they overcome significant limitations found in current state-of-the-art manual MIS procedures (e.g. imprecise motion, hand tremor, fatigue of the surgeon, limited workspace/maneuverability, etc.). Importantly, robotic systems can only reach the required high accuracy and precision when a tracking system with the corresponding accuracy and precision level for the surgical tool’s end-effector enables closed-loop feedback control. Herein, we present a tracking system meeting the above required high accuracy and precision called ASTRAS (Angular Sensor for TRAcking Systems). In this paper, the working principle and performance of ASTRAS are presented and characterized respectively. ASTRAS is arranged in a way that a tilt of a mirror produces a shift of a shadow cast on an image sensor. Since the mechanical constraints between the light source, mirrors, shadow mask, and image sensor are known, the angle can be derived from the measured shadow shift. The working principle of ASTRAS allows the measurement of 2 degrees of freedom at once. Additionally, the commercial availability of small image sensors (∼1 × 1 × 0.5 mm3) allows implementing ASTRAS in the future as a down-scaled version in surgical tools such endoscopes. The characterization of ASTRAS was performed with an experimental setup evaluating the angular measurement performance in one degree of freedom. The results revealed a precision of ∼3·10−6 rad, a thermal stability of 1.9·10-5 rad/°C, a long term drift 10-5rad/day, and a linearity error of ∼10-4 rad. Future developments will focus on implementing a miniaturized prototype and making a chain of sensors to use in articulated devices.

This work was done in the framework of the MIRACLE project devoted to the development of a flexible, articulated robotic endoscope to perform laser osteotomies (bone cutting). In order to control this robot with the required accuracy of 0.2 mm at the tip position, a tracking system needs to feed back the pose of the tip and the shape of the endoscope. One of the possible designs of such a robotic endoscope is based on an articulated device that can be tracked by measuring the bending angle at each joint. Recently, we presented (Iafolla et al., 2018) a novel angular sensor called ASTRAS (Angular Sensor for TRAcking Systems), which measures a one degree of freedom rotation by processing a shadow image cast through a shadow mask onto an image sensor. One ASTRAS will be placed at each joint of the articulated robotic endoscope in order to measure their bending angles. The planned diameter of the MIRACLE endoscope is 10 mm and it will contain several components such as the optical fiber for the laser, irrigation and sucking systems, and robot control mechanisms. However, the latest version of ASTRAS covered a volume of 40x40x55 mm3. For this reason, the most demanding requirement for the design of the final ASTRAS sensor is its miniaturization to fit the sensor inside the joint of the endoscope. Consequently, in this contribution, we investigated the possibility of miniaturizing ASTRAS and assess its limitations due to some fundamental aspects. In particular, we built a prototype based on a NanEye camera by AMS (1x1x0.5 mm3) and a micro-milled shadow mask with 0.08 mm wide slits. The tests of this prototype showed encouraging results and will be discussed. In particular, at such small dimensions, there are no unexpected optical effects (e.g. optical diffraction due to the mask) worsening the measurement. Indeed, the precision of 5 arcsec and the linearity error of 23 arcsec RMS are comparable to those of the previous bigger prototype. Further considerations and concepts related to the miniaturization of ASTRAS are also discussed in this paper.

The main objective of this work is to develop a miniaturized, high accuracy, single-turn absolute, rotary encoder called ASTRAS360. Its measurement principle is based on capturing an image that uniquely identifies the rotation angle. To evaluate this angle, the image first has to be classified into its sector based on its color, and only then can the angle be regressed. Inspired by machine learning, we built a calibration setup, able to generate labeled training data automatically. We used these training data to test, characterize, and compare several machine learning algorithms for the classification and the regression. In an additional experiment, we also characterized the tolerance of our rotary encoder to eccentric mounting. Our findings demonstrate that various algorithms can perform these tasks with high accuracy and reliability; furthermore, providing extra-inputs (e.g. rotation direction) allows the machine learning algorithms to compensate for the mechanical imperfections of the rotary encoder., Measurement, 169, ISSN:0263-2241, ISSN:1873-412X

We report a temperature-compensated FBG-based 3D shape sensor with an average positioning error of 1.4 %. The sensor consists of three single-mode fibers with four arrays of FBGs, which are glued on a substrate.

The muon anomalous magnetic moment is one of the most precisely measured quantities in particle physics and a persistent discrepancy of about 3 σ between standard model (SM) prediction and the experimental measurement has been observed. The leading order contribution aμhlo is actually the main source of uncertainty in the theoretical evaluation of the muon anomaly. It is obtained by a dispersion integral using the precision measurement of hadronic cross section. The KLOE experiment at the DAΦNE ϕ−factory in Frascati was the first to exploit Initial State Radiation (ISR) processes to obtain the e+e−→π+π−(γ) cross section below 1 GeV, that accounts for most (70%) of the leading order contribution to the muon anomaly. In year 2005 and 2008 the KLOE-collaboration has published two measurements of the π+π− cross section with the photon in the initial state emitted at small angle, and an independent measurement with the photon emitted at large angle was finalized in year 2011. These measurements were normalized using luminosity from Bhabha. In the last years, a new analysis of KLOE data has been performed for obtaining the pion form factor directly from the bin-by-bin π+π−γ to μ+μ−γ ratio. We present the results of this new measurement, showing the comparison with our previous measurements, and its impact on the hadronic contribution to the muon anomaly.

Time to Digital Converters (TDCs) are very common devices in particles physics experiments. A lot of “off-the-shelf” TDCs can be employed but the necessity of a custom DAta acQuisition (DAQ) system makes the TDCs implemented on the Field-Programmable Gate Arrays (FPGAs) desirable. Most of the architectures developed so far are based on the tapped delay lines with precision down to 10 ps, obtained with high FPGA resources usage and non-linearity issues to be managed. Often such precision is not necessary; in this case TDC architectures with low resources occupancy are preferable allowing the implementation of data processing systems and of other utilities on the same device. In order to reconstruct γγ physics events tagged with High Energy Tagger (HET) in the KLOE-2 (K LOng Experiment 2), we need to measure the Time Of Flight (TOF) of the electrons and positrons from the KLOE-2 Interaction Point (IP) to our tagging stations (11 m apart). The required resolution must be better than the bunch spacing (2.7 ns). We have developed and implemented on a Xilinx Virtex-5 FPGA a 32 channel TDC with a precision of 255 ps and low non-linearity effects along with an embedded data acquisition system and the interface to the online FARM of KLOE-2. The TDC is based on a low resources occupancy technique: the 4×Oversampling technique which, in this work, is pushed to its best resolution and its performances were exhaustively measured.

We have carried out a new direct search for the CP violating decay K-S -> 3 pi(0) with 1.7 fb(-1) of e(+)e(-) collisions collected by the KLOE detector at the Phi-factory DA Phi NE. We have searched for this decay in a sample of about 5.9 x 10(8) KSKL events tagging the K-S by means of the K-L interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake K-S tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of K-S -> 2 pi(0) events in the same sample, we set the upper limit on BR(K-S -> 3 pi(0))

We have measured the ratio cr (e(+)e(-) -> pi(+)pi(-)gamma)/sigma(e(+)e(-) -> mu(+)mu(-)gamma), with the KLOE detector at DA Phi NE for a total integrated luminosity of similar to 240 pb(-1). From this ratio we obtain the cross section sigma (e(+)e(-) -> pi(+)pi(-)gamma). From the cross section we determine the pion form factor vertical bar F-pi vertical bar(2) and the two-pion contribution to the muon anomaly a(mu) for 0.592< M-pi pi < 0.975 GeV, Delta(pi pi) a(mu) = (385.1 +/- 1.1(stat) +/- 2.7(sys+theo)) x 10(-10). This result confirms the current discrepancy between the Standard Model calculation and the experimental measurement of the muon anomaly. (c) 2013 Elsevier B.V. All rights reserved.

The ratio R-eta = Gamma(eta -> pi(+)pi(-)gamma)/Gamma(eta -> pi(+)pi(-)pi(0)) has been measured by analysing 22 million phi -> eta gamma decays collected by the KLOE experiment at DANE, corresponding to an integrated luminosity of 558 pb(-1). The eta -> pi(+)pi(-)gamma proceeds both via the rho resonant contribution, and possibly a non-resonant direct term, connected to the box anomaly. Our result, R-eta = 0.1856 +/- 0.0005(stat)+/- 0.0028(syst), points out a sizable contribution of the direct term to the total width. The di-pion invariant mass for the eta -> pi(+)pi(-)gamma decay could be described in a model-independent approach in terms of a(-) single free parameter, alpha. The determined value of the parameter alpha is alpha = (1.32 +/- 0.08(stat-0.09syst)(+0.10) +/- 0.02(theo)) GeV-2. 2012 Elsevier B.V. All rights reserved.

In the last ten years many proposals and studies have been advanced for a far-IR kilometer baseline interferometer. This paper shows the results of FISICA (Far Infrared Space Interferometer Critical Assessment), an FP7 program of the European Community. In particular, we focus on an innovative strategy to cover the plane of observation with a minimal propellant consumption. Results of some numerical simulations, carried out for a three-booms configuration, are provided.

The existence of a light dark force mediator has been tested with the KLOE detector at DAPHNE. This particle, called U, is searched for using the decay chain phi-->etaU, eta-->pi+pi-pi0, U-->e+e-. No evidence is found in 1.5 fb-1 of data. The resulting exclusion plot covers the mass range 5, Comment: 13 pages, 8 figures

"We have carried out a new direct search for the CP violating decay KS→3π0 with 1.7 fb−1 of e+e− collisions collected by the KLOE detector at the Φ-factory DAΦ NE. We have searched for this decay in a sample of about 5.9×108KSKL events tagging the KS by means of the KL interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake KS tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of KS→2π0 events in the same sample, we set the upper limit on BR(KS→3π0)⩽2.6×10−8 at 90% C.L., five times lower than the previous limit. We also set the upper limit on the η000 parameter, |η000|⩽0.0088 at 90% C.L., improving by a factor two the latest direct measurement.. . . "

The European project “Wind, Ports, and Sea” (VPM), funded by the European Cross-border Programme “Italy-France Maritime 2007–2013”, aims to improve the safety conditions and to reduce the hazards by the development of a coupled monitoring and forecast system of the sea-state outside the main harbors of the Northern Tyrrhenian and Ligurian Seas. In particular, the sea and wind forecasts are evaluated by using a numerical model specifically implemented for this project and the monitoring system is made of measuring stations installed on the coast near the harbor areas. The Port Authority of La Spezia has implemented a pilot project based on a new method, called OS-IS (Ocean Seismic-Integrated Solution, [1]), for the inland remote monitoring of the sea. The key advantage of OS-IS is that is installed inland, inside a building, and there are no parts in the sea. The core elements of the system are high sensitivity accelerometers and specifically developed algorithms for the evaluation of the sea state using the micro-seismic signals on the basis of mathematical models and fitting calibration factors. After more than one year since the first installation, OS-IS has shown a high level of reliability and the validity of the measurements has been demonstrated by comparison with those of the buoys. In the following, the installed systems will be shortly described and compared with the conventional methods.

FISICA (Far Infrared Space Interferometer Critical Assessment) is an FP7 program of the European community that aims to bring together the leading international experts on FIR (Far InfraRed) space instrumentation, in the effort to identify the scientific questions connected to high spatial resolution observations in the FIR and to translate these questions into a technological definition of a FIR space mission. To this finality the technologies relevant for a space interferometer which are at a low Technology Readiness Level will be studied and analyzed, trying to implement the appropriate solutions to current problems. The outcome of this study will advance the knowledge and technology required for a future FIR mission, consolidating the scientific community and bringing world-wide expertise to the EU consortium.

In the new KLOE2 experiment, at DA Φ NE particle accelerator of LNF-INFN, a pair of tagger detectors will be installed in order to investigate gamma–gamma physics. We shall need to acquire a 32 bits pattern for each detector and to allow a high time-resolution event reconstruction with KLOE data. The acquisition system will be implemented with Virtex-5 FPGA in order to avoid expensive TDC. The real time sampling and holding system, reference providing system, memorization and transfer data system will be described.

The gamma–gamma physics is a relevant part of the physics programme of KLOE2 project at DA Φ NE . In particular, there is a strong interest to measure the cross-section for the process γ γ → π 0 π 0 in the low energy region for its relevance in the context of the assessing the existence and nature of the sigma meson. In this talk we present the tagging system for the final leptons which we are developing. We will illustrate the characteristics and performance required for the detectors and the acquisition system. In particular, this system should be able to acquire data for each bunch crossing and therefore to a frequency of 368 MHz.

The ϕ-factory DAΦNE offers a possibility to select pure kaon beams, charged and neutral ones. In particular, neutral kaons from ϕ → K S K L are produced in pairs and the detection of a K S ( K L ) tags the presence of a K L ( K S ) . This allows to perform precise measurements of kaon properties by means of KLOE detector. Another advantage of a ϕ-factory consists in fact that the neutral kaon pairs are produced in a pure quantum state ( J P C = 1 − − ) , which allows to investigate CP and CPT symmetries via quantum interference effects, as well as the basic principles of quantum mechanics. A review of the most recent results of the KLOE experiment at DAΦNE using pure kaon beams or via quantum interferometry is presented together with prospects for kaon physics at KLOE–2.

The GIB boards (General Interface Boards) and the dedicated crate were designed and realized by a team of the SEA (Servizio Elettronica e Automazione) group of the research division. The main task of these boards is to interface the front-end electronics (FE or transition boards) dedicated to different detectors of KLOE-2 experiment with the higher stages of the acquisition system. The GIBs are equipped with many types of interfaces: optical link, RS232, USB, Ethernet and a 184-pins connector for the crate; the link between the GIBs and the front-end boards is done through the backplane of the crate. About 90 boards were produced and some tests were necessary to discard the broken ones. The toughest is the test of the pins for the crate: so we developed a dedicated system and software in order to accomplish it in a fast and sure way. We wrote this note to show how this system works in the case of a future production of new GIB boards.

In order to fully reconstruct to the reaction e+e- to e+e- gamma-gamma in the energy region of the phi meson production, new detectors along the DAFNE beam line have to be installed in order to detect the scattered e+e-. The High Energy Tagger (HET) detector measures the deviation of leptons from their main orbit by determining their position and timing so to tag gamma-gamma physics events and disentangle them from background. The HET detectors are placed at the exit of the DAFNE dipole magnets, 11 m away from the IP, both on positron and electron lines. The HET sensitive area is made up of a set of 28 plastic scintillators. A dedicated DAQ electronics board based on a Xilinx Virtex-5 FPGA have been developed for this detector. It provides a MultiHit TDC with a time resolution of the order of 500 ps and the possibility to acquire data any 2.5 ns, thus allowing to clearly identify the correct bunch crossing. First results of the commissioning run are presented., Submitted to proceedings of the 12th Pisa Meeting on Advanced Detectors 2012, La Biodola, Isola d'Elba, Italy

Nell'ambito delle attività di sviluppo della camera a deriva dell'esperimento SuperB è stato fatto uno studio di fattibilità di un TDC con risoluzione dell'ordine del ns per le misure dei tempi di deriva degli elettroni. L'elettronica di front-end (di cui il TDC fa parte) verrà istallata nella piattaforma posizionata sopra al rivelatore per contenere la lunghezza dei cavi e non degradare eccessivamente il rapporto segnale/rumore: l'intero sistema deve quindi essere tollerante a una radiazione di background che al momento è stimata dell'ordine del kRad/anno. Fino a pochi anni fa i suddetti requisiti avrebbero portato alla realizzazione di un circuito dedicato (ASIC) con i conseguenti costi e tempi di sviluppo poiché i dispositivi FPGA disponibili erano o basati su SRAM, e quindi incompatibili con il background di radiazioni previsto, o non avevano le prestazioni sufficienti. Le più moderne ed efficienti FPGA prodotte dalla ACTEL e basate su memorie di tipo FLASH (e quindi più resistenti alla radiazione) hanno apportato una notevole semplificazione e riduzione di costi nello sviluppo di applicazioni che devono funzionare in presenza di moderate dosi di radiazione. In questo contesto lo studio di fattibilità del TDC, basato sulla tecnica "4xOversampling" e implementata su ACTEL ProAsic3, ha dimostrato che è possibile implementare fino a 32 canali con relativo sistema di readout. Infine, per mitigare ulteriormente gli effetti causati dalla radiazione, è stata elaborata una innovativa logica decisionale che consente una notevole semplificazione nella realizzazione del circuito stampato.

For the KLOE upgrade (KLOE-2) we built a new couple of subdetectors: the HETs, two position detectors for electrons and positrons dedicated to the study of the γγ physics. The developed Data AcQuisition (DAQ) system of these two detectors is fully compatible with the data acquisition and trigger systems of KLOE. The DAQ of the HETs transfers the data to the KLOE acquisition through a VME bus while the trigger systems are connected through lemo cables. The electrical ground of the two systems must not to be connected in order to reduce the noise effects. This led us to develop a decoupling board called DisOpto.

In order to reconstruct gamma-gamma physics events tagged with High Energy Tagger (HET) in the KLOE-2 (K LOng Experiment 2), we need to measure the Time Of Flight (TOF) of the electrons and positrons from the KLOE-2 Interaction Point (IP) to our tagging stations (11 m apart). The required resolution must be better than the bunch spacing (2.7 ns). We have developed and implemented on a Xilinx Virtex-5 FPGA a Time to Digital Converter (TDC) with 625 ps resolution (LSB) along with an embedded data acquisition system and the interface to the online FARM of KLOE-2. We will describe briefly the architecture of the TDC and of the Data AcQuisition (DAQ) system. Some more details will be provided about the zero-suppression algorithm used to reduce the data throughput., Submitted to proceedings of the 12th Pisa Meeting on Advanced Detectors 2012, La Biodola, Isola d'Elba, Italy

L'upgrade di KLOE (KLOE-2) prevedeva l'installazione di un sistema di 'tagging', per lo studio della fisica gamma-gamma, costituito da 2 nuove coppie di rivelatori: HET e LET. Il sistema di acquisizione (DAQ) del rivelatore HET e' stato implementato su una scheda VME basata su una FPGA (Virtex-5). Esso consiste principalmente di un TDC, un sistema di elaborazione dati (Zero suppression) e una interfaccia VME. Nella prima parte di questo documento sono descritti i principi di funzionamento e l'architettura del TDC e del DAQ; nella seconda parte sono descritte le modalita' di configurazione del sistema e la formattazione dei dati in uscita.

Cluster counting technique [1] can improve particles identification in tracking devices, like drift chambers, by removing Landau tails. The technique is based on the counting of primary ionization clusters and, to be implemented, it requires slow drift velocity gas mixtures, fast amplifiers, fast sampling devices (> 1GS/s) and, finally, correct termination of the sense wire (to avoid signal reflection). Because the termination resistor low value, its noise contribution is not negligible then setting a lower limit on the readout chain noise.

We present a measurement of η meson production in photon-photon interactions produced by electron-positron beams colliding with $ \sqrt{s}=1 $ GeV. The measurement is done with the KLOE detector at the ϕ-factory DAΦNE with an integrated luminosity of 0.24 fb−1. The e + e − → e + e − η cross section is measured without detecting the out-going electron and positron, selecting the decays η → π + π − π 0 and η → π 0 π 0 π 0. The most relevant background is due to e + e − → ηγ when the monochromatic photon escapes detection. The cross section for this process is measured as σ(e + e − → ηγ) = (856 ± 8stat ± 16syst) pb. The combined result for the e + e − → e + e − η cross section is σ(e + e − → e + e − η) = (32.72 ± 1.27stat ± 0.70syst) pb. From this we derive the partial width Γ(η → γγ) = (520 ± 20stat ± 13syst) eV. This is in agreement with the world average and is the most precise measurement to date.

The KLOE experiment has acquired an integrated luminosity greater than 2.5 fb^{-1} at the peak of ø-resonance on the e^{+]e^{-} DAΦNE collider in the Frascati National Laboratory (LNF). New data taking with the upgraded detector (KLOE-2) and DAΦNE should start in the end of 2011. Main modifications of the detector and new interaction region give a unique possibility to collect about 20 fb^{-1} in 3 years. The KLOE-2 wide scientific program which contains the experimental study of CP and CPT symmetries, quantum decoherence, γγ physics and search of the dark matter is presented and briefly discussed.