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Since the 2018 IAEA FEC Conference, FTU operations have been devoted to several experiments covering a large range of topics, from the investigation of the behaviour of a liquid tin limiter to the runaway electrons mitigation and control and to the stabilization of tearing modes by electron cyclotron heating and by pellet injection. Other experiments have involved the spectroscopy of heavy metal ions, the electron density peaking in helium doped plasmas, the electron cyclotron assisted start-up and the electron temperature measurements in high temperature plasmas. The effectiveness of the laser induced breakdown spectroscopy system has been demonstrated and the new capabilities of the runaway electron imaging spectrometry system for in-flight runaways studies have been explored. Finally, a high resolution saddle coil array for MHD analysis and UV and SXR diamond detectors have been successfully tested on different plasma scenarios.

The diagnostic performances of photodetectors based on Chemical Vapor Deposition (CVD) single crystal diamonds that were installed on one of the equatorial ports of the FTU tokamak during the last six months of operation of the machine are reported. Examples of plasma fast events have been collected in several different plasma conditions, confirming the fast response capabilities of diamond detectors and the high S/N ratio. During the Runaway Control and Mitigation experiments, for example, the so-called Anomalous Doppler Instabilities were observed as sharp peaks of Ly-α emission caused by fast electrons hitting the wall, as a result of RE beam instabilities, perfectly correlated in time with other magnetic diagnostics and fast EC polychromator signals. Fast oscillations in the plasma emission are also observed in the presence of tearing modes, while other interesting observations relate to pellet ablation processes. The CVD diamond detectors were installed on FTU in view of their possible use for replacement of the Si photodiodes currently adopted for Soft X-Ray tomography (SXT) on future devices with harsher radiation environments. In fact, it was realized that the relatively flat response of the UV diamond sensor opened the possibility of using these detectors as bolometers. The first encouraging results have prompted launching an R&D program for the development of full-fledged diamond bolometers, which will be especially well suited for the coverage of the divertor and edge regions in high performance devices, in the energy range from 10 eV to about 20 keV.

PURPOSE Oral melphalan and dexamethasone (MDex) were considered a standard of care in light-chain (AL) amyloidosis. In the past decade, bortezomib has been increasingly used in combination with alkylating agents and dexamethasone. We prospectively compared the efficacy and safety of MDex and MDex with the addition of bortezomib (BMDex). METHODS This was a phase III, multicenter, randomized, open-label trial. Patients were stratified according to cardiac stage. Patients with advanced cardiac stage (stage IIIb) amyloidosis were not eligible. The primary end point was hematologic response rate at 3 months. This trial is registered with ClinicalTrials.gov identifier NCT01277016. RESULTS A total of 109 patients, 53 in the BMDex and 56 in the MDex group, received $1 dose of therapy (from January 2011 to February 2016). Hematologic response rate at 3 months was higher in the BMDex arm (79% v 52%; P 5 .002). Higher rates of very good partial or complete response rates (64% v 39%; hazard ratio [HR], 2.47; 95% CI, 1.30 to 4.71) and improved overall survival, with a 2-fold decrease in mortality rate (HR, 0.50; 95% CI, 0.27 to 0.90), were observed in the BMDex arm. Grade 3 and 4 adverse events (the most common being cytopenia, peripheral neuropathy, and heart failure) were more common in the BMDex arm, occurring in 20% versus 10% of cycles performed. CONCLUSION BMDex improved hematologic response rate and overall survival. To our knowledge, this is the first time a controlled study has demonstrated a survival advantage in AL amyloidosis. BMDex should be considered a new standard of care for AL amyloidosis. © 2020 by American Society of Clinical Oncology.

The popularity of running among young athletes has significantly increased over the past few decades. As the number of children who participate in running increases, so do the potential number of injuries to this group. Proper care of these athletes includes a thorough understanding of the unique physiology of the skeletally immature athlete and common injuries in this age group. Treatment should focus on athlete education, modification of training schedule, and correction of biomechanical deficits contributing to injury. Early identification and correction of these factors will allow a safe return to running sports.

This work takes into account three Cartesian manuals diffused in 17th century France (Claude Gadroys, Le système du monde selon les trois hypothèses (Paris, Desprez 1675); Jacques Rohault, Traité de physique (Paris, 1671); Pierre-Sylvain Régis, Cours entier de philosophie, ou système general selon les principes de M. Descartes contenant la logique, la metaphysique, la physique et la morale (Amsterdam, 1691)) in order to question if the development of an empirical attitude in the scientific research influenced their approaches to the study of motion. The article intends to deepen the role that these authors give to God in the physical structure of the universe with the purpose of investigating whether their analysis of motion is untainted by the metaphysical component or on what terms it remains linked to it.

The Système de philosophie (1691) by Pierre Sylvain Régis can be considered as the achievement both of the scientific liveliness of the Académie des Sciences in the 17th century and of its fruitful relationship with the Royal Society. Since it aims to shape the new conception of the universe in terms of a system, the Système represents one of the most mature achievements of Cartesian philosophy and it is characterized by an empirical interpretation of Descartes’ thought. The Système therefore reflects two important phenomena occurring in the Europe of the 17th century: the scientific revolution and the proliferation of Academies. In fact, this ambitious work could be undertaken with the support of the Académie des Sciences and the Journal des Sçavants. My paper will analyse the French context by focusing to outline the role which the Académie de France had both in France, as the medium of dissemination of the new philosophy despite censorship, and abroad, in particular through the relationship with the Royal Society in England. I aim to analyse the role of the Journal des Sçavants as a means to share ideas other than by correspondence and as a trait d’union between “rationalist France” and “empiricist England”. I intend to question whether it is possible to establish a connection between the empirical interpretation of French Cartesianism, the consolidation of the Académie de France and the employment of new means of academic communication. The paper will show that the second half of 17th century France represents a remarkable exception to the conventional picture, which states that in 17th century Europe, following the success of a mechanistic interpretation of reality, two philosophical school clashed: rationalism, predominating on the continent, and empiricism, in England.

An innovative monolithic diamond based Δ E - E charged particle telescope was fabricated in a layered structure featuring an ultrathin Δ E stage coupled to an E stage, about 2 μ m and 500 μ m in thickness, respectively. The diamond telescope was characterized in coincidence mode using α -particles emitted by a 241Am source, whose energy can be reduced by traveling in air at different pressures. The experimental Δ E - E scatter plots were analyzed and compared with the results from the nuclear simulation program SRIM. A good agreement between the experimental and simulated data as well as a good detector performance were found in terms of energy resolution and charge collection efficiency. Our experimental results indicate that the developed Δ E - E diamond telescope prototype can be used to provide information about the type and the energy of particles in nuclear physics experiments. In addition, the micrometric size sensitive volume of the Δ E diamond detector of the proposed device is particularly promising for the microdosimetric characterization of hadron beams.

High-energy electron beams generated by linear accelerators, typically in the range 6 to 20 MeV, are used in small field sizes for radiotherapy of localized superficial tumors. Unshielded silicon diodes (Si-D) are commonly considered suitable detectors for relative dose measurements in small electron fields due to their high spatial resolution. Recently, a novel synthetic single crystal diamond diode (SCDD) showed suitable properties for standard electron beams and small photon beams dosimetry. The aim of the present study is twofold: to characterize 6 to 15 MeV small electron beams shaped by using commercial tubular applicators with 2, 3, 4 and 5 cm diameter and to assess the dosimetric performance under such irradiation conditions of the novel SCDD dosimeter by comparison with commercially available dosimeters, namely a Si-D and a plane-parallel ionization chamber. Percentage depth dose curves, beam profiles and output factors (OFs) were measured. A good agreement among the dosimeters was observed in all of the performed measurements. As for the tubular applicators, two main effects were evidenced: (i) OFs larger than unity were measured for a number of field sizes and energies, with values up to about 1.3, that is an output 30% greater than that obtained at the 10 × 10 cm 2 reference field; (ii) for each diameter of the tubular applicator a noticeable increase of the OF values was observed with increasing beam energy, up to about 100% in the case of the smaller applicator. This OF behavior is remarkably different from what typically observed for small blocked fields having the same size and energy as those used in this study. OFs for tubular applicators depend considerably on the field size, so interpolation is unadvisable to predict the linear accelerator output for such applicators whereas reliable high-resolution detectors, as the silicon and diamond diodes used in this work allow OF measurements with uncertainties of about 1%. © 2013 Institute of Physics and Engineering in Medicine. Printed in the UK & the USA.

Diamond is studied since many years as potential radiation detector material. In the last years, there has been an increasing interest about the capability of diamond to withstand harsh working conditions including high temperature. The latter capability depending upon the large band gap and the excellent thermal properties of diamond. At ENEA C.R. Frascati, diamond detectors operating at high temperature are studied since many years as candidate neutron monitors for nuclear fusion reactors. Diamond metallization was realized using different metals deposited on commercial diamond films, 100 or 500 μm thick. This paper reports the results for two detectors made with metal Cr and Ag contacts, respectively. The maximum working temperature under 14 MeV neutron irradiation, while operating the detector in spectrometric mode, was in the range 220-240 °C. The best performance was obtained using Ag metal contacts. It was also observed that once cooled down below the maximum working temperature the detector performances are recovered. Furthermore, it was observed that metallization can be damaged after long lasting operation at high temperature. In the attempt to overcame this issue a new detector was realized made with one Schottky Cr-diamond metal contact on one side and an ohmic, not metallic, contact on the other side. A commercial film 100 micron thick was used. This detector shown excellent performances well above 300°C. © 2016 IEEE.

A transient lateral photovoltaic effect (LPE) is reported for a metal-semiconductor structure of synthetic single crystal diamond (SCD). A SCD Schottky photodiode was specifically designed to measure a LPE under collimated irradiation from a tunable pulsed laser. A transient lateral photovoltage parallel to the Schottky junction was indeed detected. LPE on the p-type doped SCD side showed a non-linearity of 2% and a fast response time, with a rise time of 2 μs and a decay time of 12 μs. The position sensitivity (up to 30 mV/mm at a laser wavelength of 220 nm and a pulse energy density of 2.9 μJ/mm2) was measured as a function of laser wavelength, and an ultraviolet (UV)-to-visible contrast ratio of about four orders of magnitude with a sharp cutoff at 225 nm was observed. Our results demonstrate that a large LPE at UV wavelengths is achievable in synthetic single crystal diamond, potentially opening opportunities for the study and application of LPE in diamond and for the fabrication of high performance v...

Diamond is a promising platform for the development of technological applications in quantum optics and photonics. The quest for color centers with optimal photo-physical properties has led in recent years to the search for novel impurity-related defects in this material. Here, we report on a systematic investigation of the photo-physical properties of two He-related (HR) emission lines at 535 nm and 560 nm created in three different diamond substrates upon implantation with 1.3 MeV He+ ions and subsequent annealing. The spectral features of the HR centers were studied in an "optical grade" diamond substrate as a function of several physical parameters, namely the measurement temperature, the excitation wavelength and the intensity of external electric fields. The emission lifetimes of the 535 nm and 560 nm lines were also measured by means of time-gated photoluminescence measurements, yielding characteristic decay times of (29 +- 5) ns and (106 +- 10) ns, respectively. The Stark shifting of the HR centers under the application of an external electrical field was observed in a CVD diamond film equipped with buried graphitic electrodes, suggesting a lack of inversion symmetry in the defects' structure. Furthermore, the photoluminescence mapping under 405 nm excitation of a "detector grade" diamond sample implanted at a 1x1010 cm-2 He+ ion fluence enabled to identify the spectral features of both the HR emission lines from the same localized optical spots. The reported results provide a first insight towards the understanding of the structure of He-related defects in diamond and their possible utilization in practical applications, Comment: 9 pages, 3 figures

This paper reports about the performances of single crystal diamond (SCD) detectors operated at high temperature (up to 200 °C) and irradiated with alpha particles. Two different types of SCD detectors were studied: (a) SCD of commercial type; (b) SCD produced at Rome “Tor Vergata” University and characterized by a layered structure. The first measurement of the response function vs. temperature of commercial SCD detector irradiated with 14 MeV neutrons and heated up to 140 C is also reported. The measurements pointed out the superior performance of diamond with respect to other detectors (e.g., silicon) when operated at high temperature. However, the present work also pointed out that a diamond detector assembled to operate at room temperature can suffer from mechanical stress when operated at high temperature. The results indicate that, with a proper design, diamond detectors can be suitable for operation at high temperature.

irradiation with high-energy radiotherapic photon beams. The stability of the detector response and its dose and dose rate dependence were measured. Different square field sizes ranging from 1 × 1c m 2 to 10 × 10 cm 2 were used during comparative dose distribution measurements by means of percentage depth dose curves (PDDs), lateral beam profiles, and output factors. The angular and temperature dependence of the diamond detector response were also studied. Results: The detector response shows a deviation from linearity of less than ±0.5% in the 0.01‐7 Gy range and dose rate dependence below ±0.5% in the 1‐6 Gy/min range. PDDs and output factors are in good agreement with those measured by the reference ionization chamber within 1%. No angular dependence is observed by rotating the detector along its axis, while ∼3.5% maximum difference is measured by varying the radiation incidence angle in the polar direction. The temperature dependence was investigated as well and a ±0.2% variation of the detector response is found in the 18‐40 ◦ C range. Conclusions: The obtained results indicate the investigated synthetic diamond-based detector as a candidate for small field clinical radiation dosimetry in advanced radiation therapy techniques. © 2012 American Association of Physicists in Medicine .[ http://dx.doi.org/10.1118/1.4729739]

Background: Inulin has been increasingly used due to its beneficial nutritional attributes as prebiotic ingredient and nutritional values. The burdock tuberous could be a source of inulin. Now a daychr('39')s Ultrasound has attracted considerable interest in food science and technology due to its promising effects in food processing and preservation. The ultrasonically induced cavitations were shown to increase the permeability of the plant tissues. The mechanical effects of ultrasound provide a greater penetration of solvent into cellular materials. In some cases direct sonication increased the efficiency of extraction at lower temperatures and shorter time. Objective: O ptimization of extraction conditions for burdock tubers using sonication. Methods: In this research, a series of statistically designed studies such as central composite design (CCD) and response surface methodology (RSM) were performed to investigate the effect of each of the independent variables, ultrasonic waves (20-100%), exposure time (5-25 min) & treatment temperature (20-60 ° C) on yield of inulin extraction from burdock tubers. Response surface methodology was employed to optimize multiple variables to predict the best performance conditions with a minimum number of experiments. According to Determination of inulin content of extraction liquid, Total carbohydrate and Reducing sugar were determined and finally the inulin content was measured with the difference between total carbohydrate and reducing sugars. Inulin extraction yield (%) was calculated using the following relationship = (inulin content × volume of extraction liquid/mass of Burdock tuber powder) ×100. Results: Based on canonical analysis, the optimal conditions for maximizing inulin extraction yield (24.36%) were at 36.85 °C for 25.4 min and amplitude of 83.2%. Conclusions: application of ultrasound would be a promising method to enhance the extraction process.

Background: Inulin is widely used in functional foods throughout the world for its health-promoting and technological properties. Burdock tuber can be a valuable source of inulin. It is cultivated widely in the northern & western parts of Iran. But scarce studies about its extraction exist. It has been increasingly used in functional foods due to its texture improvement, sugar and fat replacer characteristics and beneficial nutritional attributes, as prebiotic ingredient. Objective: Optimize conventional extraction of inulin, by using central composite design (CCD) and response surface methodology (RSM). Methods: In this Research, a series of statistically designed studies such as central composite design and response surface methodology were performed to investigate the effect of each of the independent variables, solvent: solid ratio (5 - 15 v/w), temperature (40 - 90°C) and time (5 - 40 min) on yield of inulin extraction from burdock tubers. Response surface methodology was employed to optimize multiple variables to predict the best performance conditions with a minimum number of experiments. According to determination of inulin content of extraction liquid, firstly total carbohydrate was determined by the phenolsulphuric acid method, then reducing sugar was determined by the dinitrosalicylic acid method and finally the inulin content was measured with the difference between total carbohydrate and reducing sugars. Inulin extraction yield (%) was calculated using the following relationship = (inulin content × volume of extraction liquid/mass of Burdock tuber powder) ×100. Results: Based on canonical analysis, the optimal conditions for maximizing inulin extraction yield (12%) were at 66.14°C for 37.6 min and solvent: solid ratios of 14: 98 (v/w). Conclusion: Using the response surface methodology, the optimum set of the independent variables was obtained graphically in order to obtain the desired levels of inulin extraction.

In this paper a novel on-line tritium monitor is presented. It is made with a single crystal diamond detector (SCD) covered with a thin layer of LiF 95% enriched in 6Li. Thermal neutrons impinging on the LiF layer produce α and T ions which are detected by the active diamond. The pulse height spectrum shows two separated peaks due to α and T ions respectively. By a proper calibration in a reference thermal flux the number of 6Li atoms and thus the absolute n+6Li→α+T reaction rate per unitary flux can be established. Once calibrated the detector can be used to measure the tritium production. Due to the many outstanding properties of diamond this detector could operate in the harsh working conditions of a fusion breeding blanket. A test of this detector was performed at the 14 MeV Frascati Neutron Generator (FNG). The detector was inserted inside a mock-up of the European Helium Cooled Lithium Lead (HCLL) Tritium Blanket Module (TBM), designed to validate the neutronic database for fusion application. The mock-up of the TBM was designed to perform a full set of experiments to validate tritium production code prediction comparing the experimental results with calculations. The measured tritium rates with the Li-Diamond detector are described in this paper. Comparison with calculations is in progress and will be reported in a future paper.

The aquatic zoonotic pathogen Streptococcus iniae represents a threat to the worldwide aquaculture industry and poses a risk to humans who handle raw fish. Because little is known about the mechanisms of S. iniae pathogenesis or virulence factors, we established a high-throughput system combining whole-genome pyrosequencing and transposon mutagenesis that allowed us to identify virulence proteins, including Pdi, the polysaccharide deacetylase of S. iniae, that we describe here. Using bioinformatics tools, we identified a highly conserved signature motif in Pdi that is also conserved in the peptidoglycan deacetylase PgdA protein family. A Δpdi mutant was attenuated for virulence in the hybrid striped bass model and for survival in whole fish blood. Moreover, Pdi was found to promote bacterial resistance to lysozyme killing and the ability to adhere to and invade epithelial cells. On the other hand, there was no difference in the autolytic potential, resistance to oxidative killing or resistance to cationic antimicrobial peptides between S. iniae wild-type and Δpdi. In conclusion, we have demonstrated that pdi is involved in S. iniae adherence and invasion, lysozyme resistance and survival in fish blood, and have shown that pdi plays a role in the pathogenesis of S. iniae. Identification of Pdi and other S. iniae virulence proteins is a necessary initial step towards the development of appropriate preventive and therapeutic measures against diseases and economic losses caused by this pathogen.

A number of diamond detectors, obtained by a two-step growing procedure by chemical vapour deposition (CVD) technique, have been grown on a low cost commercial high temperature high pressure (HTHP) Ib single crystal diamond. The first diamond layer is 15 mu m thick and heavily doped by boron. A 35 mum thick layer of intrinsic high purity and high quality CVD diamond is then grown on top of the doped diamond. A metal contact (aluminium 100 nm thick) is deposited on top of the intrinsic diamond. One of these devices has been placed in the beam of the station 9.1 of Synchrotron Radiation Source at Daresbury laboratory (UK) and several tests have been performed to assess the linearity of responsivity as a function of the photon flux, the long term stability, and the response to the sudden onset of radiation. The device shows an excellent linearity and long term stability (tested in the order of hours), while the response to the onset of radiation have still to be understood. The results obtained can open up the path to the construction of extremely radiation hard devices to be exploited as X-ray beam monitor.

This paper reports on the three new Single Crystal Diamond (SCD) detectors installed at JET for the 2008 Restart campaign. The yields of total neutrons produced during DD plasma pulses as well as the time dependent neutron emission have been measured. The three detectors present some main new developments as for their fabrication characteristics, embeddings and electronic chains. The first detector is 200 μm thick and is embedded in paraffin. The second detector is 104 μm thick and is covered by a thermally evaporated 3 μm thick 6 LiF film in order to detect the total and the 14-MeV neutrons. In addition, it is surrounded by a 2.5-cm thick polyethylene shield to enhance its thermal neutron response. The third detector is operated in an innovative way that is with a single low capacitance super-screened cable and its whole electronic chain put outside the JET Torus Hall. Furthermore it uses fast electronics, suitable to the fast diamond response pulse (

We report on extreme UV (EUV) photodetectors based on CVD single crystal diamond in a p-type/intrinsic/metal configuration fabricated and tested at Roma “Tor Vergata” University laboratory, operating in a sandwich geometry. Particular care has been devoted to the design of the device geometry in order to take advantage of the internal junction electric field and to minimize the signal contribution arising from secondary electron emission, which is known to strongly affect the detection properties in the UV and EUV regions. The device has been characterized in the EUV spectral region by using both He and He–Ne DC gas discharge radiation sources and a toroidal grating vacuum monochromator, with 5 A wavelength resolution. The reproducibility test has been performed on several photodetectors showing a high uniformity of the device performances. The devices showed negligible undesired effects such as persistent photocurrent and memory effects, resulting in extremely promising stability features of the p-type/intrinsic/metal structured device. The devices have been tested at different bias voltages between 0 and 15 V, showing the best performances at 0 bias voltage. Finally, the external quantum efficiency (EQE), as well as the responsivity have been measured in the range 20 to 100 nm.

The aim of the present study is to evaluate the dosimetric properties of synthetic single crystal diamond dosimeters developed at Rome “Tor Vergata” University in different radiation therapy techniques. The detectors were firstly characterized in terms of electrical properties by means of C-V and I-V curves. A dosimetric characterization was performed both in reference condition and under high energy electron and proton beams. In all the utilized techniques, the detector showed high reproducibility, linearity, independence on the radiation energy and dose rate. The obtained results indicate that diamond dosimeters are suitable for a very wide range of radiation therapy application, making such devices very versatile tools for precise dose measurements in clinical therapeutic applications.

An innovative diamond detector layout is presented that is designed to operate at high temperature under intense neutron and gamma fluxes. It is made of a 500 μm "electronic grade" diamond film with 100 nm thick Ag metal contacts deposited onto each surface of the film by means of thermal evaporation. A 2μm thick layer of 6LiF has been deposited on top of one of the two Ag contacts to make the detector sensitive to thermal neutrons. The device was tested at the ISIS spallation neutron source (Rutherford Appleton Laboratory, UK) using the INES beam line. The detector was continuously irradiated for 100 hours in vacuum (p = 10-5 mbar), exposed to a neutron flux of about 106 n cm-2 s-1 at a temperature T = 150°C. The aim of this experiment was to study the time dependence of the diamond detector performance while operating at high temperature under irradiation, providing a first experimental proof of reliable continuous operation for 100 hours at high temperature in a harsh environment. Copyright © EPLA, 2016.

In the present paper, the performances of single crystal diamond detectors "ad hoc" designed to operate at high temperature are reported. The detectors were realized using commercial CVD single crystal diamond films, 500 micron thick with metal contacts deposited by sputtering method on each side. The new detector layout is based upon mechanical contacts between the diamond film and the electric ground. The detector was first characterized by measuring the leakage current as function of temperature and applied biasing voltage (I-V characteristics). The results obtained using two different metal contacts, Pt and Ag respectively, while irradiated with 14 MeV neutrons at the Frascati neutron generator (FNG) are reported and compared. It is shown that diamond detectors with Ag metal contacts can be properly operated in spectrometric mode up to 240°C with energy resolution (FWHM) of about 3.5%. © 2016 IOP Publishing Ltd and Sissa Medialab srl.

Artificial diamond neutron detectors recently proved to be promising devices to measure the neutron production on large experimental fusion machines. Diamond detectors are very promising detectors to be used in fusion environment due to their radiation hardness, low sensitivity to gamma rays, fast response and high energy resolution. High quality “electronic grade” diamond films are produced through microwave chemical vapour deposition (CVD) technique. Two CVD diamond detectors have been installed and operated at joint European torus (JET), Culham Science Centre, UK. One of these detectors was a polycrystalline CVD diamond film; about 12 mm2 area and 30 μm thickness while the second was a monocrystalline film of about 5 mm2 area and 20 μm thick. Both diamonds were covered with 2 μm of lithium fluoride (LiF) 95% enriched in 6Li. The LiF layer works as a neutron-to-charged particle converter so these detectors can measure thermalized neutrons. Their output signals were compared to JET total neutron yield monitors (KN1 diagnostic) realized with a set of uranium fission chambers. Despite their small active volumes the diamond detectors were able to measure total neutron yields with good reliability and stability during the recent JET experimental campaign of 2006.

Diamond based thermal neutron flux monitors have been fabricated using single crystal diamond films, grown by chemical vapour deposition. A 3 μm thick 6 LiF layer was thermally evaporated on the detector surface as a converting material for thermal neutron monitoring via the 6 Li(n, α) T nuclear reaction. The detectors were tested in a fission nuclear reactor. One of them was positioned 80 cm above the core midplane, where the neutron flux is 2.2 x 10 9 neutrons/cm 2 s at 1 MW resulting in a device count rate of about 150000 cps. Good stability and reproducibility of the device output were proved over the whole reactor power range (up to 1 MW). During the irradiation, several pulse height spectra were recorded, in which both products of the 6 Li(n, a) T reaction, e.g. 2.73 MeV tritium and the 2.06 MeV a, were clearly identified, thus excluding a degradation of the detector response. A comparison with a reference fission chamber monitor pointed out a limitation of the adopted readout electronics at high count rates, due to multiple pile-up processes. However, once this effect is properly accounted for, a good linearity of the diamond flux monitor response is observed as a function of the fission chamber one, as well as an excellent agreement between the temporal behaviour of the two detector response.

IBIC (Ion Beam Induced Charge) technique has been used in order to characterize single crystal epitaxial CVD diamond film with respect to homogeneity and stability of the response (in terms of charge collection efficiency, cce) as a function both of counting rate and of the number of counts per unit surface area. The maximum shift of cce peak, under a 1.2 MeV proton microbeam, is 1.5% for counting rates from 43 to 4330 Hz, while the homogeneity, evaluated as the standard deviation with respect to the average value of cce over strip-like regions 60–100 μm wide and 800–1200 μm long, is 0.5%. Counting rates per unit surface area were between 30 and about 15,000 Hz/mm 2 . A total number of counts per unit area up to 9 10 6 counts/mm 2 was reached without noticing any polarization effect due to trapped charge. Moreover, the functionality of a new kind of bulk electrode, realized by a boron doped buffer layer laterally contacted with Ag paste, has been checked by measuring cce at different proton ranges.

The detection properties of heteropitaxial (polycrystalline, pCVD) and homoepitaxial (single crystal, scCVD) diamond films grown by microwave chemical vapor deposition (CVD) in the Laboratories of Roma “Tor Vergata” University are reported. The pCVD diamond detectors were tested with α -particles from different sources and 12 C ions produced by 15 MV Tandem accelerator at Southern National Laboratories (LNS) in Catania (Italy). pCVDs were also used to monitor 14 MeV neutrons produced by the D-T plasma at Joint European Torus (JET), Culham, U.K. The limit of pCVDs is the poor energy resolution. To overcome this problem, we developed scCVD diamonds using the same reactor parameters that optimized pCVD diamonds. scCVD were grown on a low cost (1 0 0) HPHT single crystal substrate. A detector 110 μ m thick was tested under α -particles and under 14 MeV neutron irradiation. The charge collection efficiency spectrum measured under irradiation with a triple α -particle source shows three clearly resolved peaks, with an energy resolution of about 1.1 % . The measured spectra under neutron irradiation show a well separated C ( n , α 0 ) 9 Be 12 reaction peak with an energy spread of 0.5 MeV for 14.8 MeV neutrons and 0.3 MeV for 14.1 MeV neutrons, which are fully compatible with the energy spread of the incident neutron beams.

This work reports on the development and characterization of bi-dimensional deep-UV sensor arrays based on synthetic diamond to address the requirements of space-born astrophysical experiments. The material was synthesized at the University of Rome “Tor Vergata” where both heteroepitaxial polycrystalline diamond films and homoepitaxial single-crystal diamonds are grown using a tubular MWCVD reactor. The quality of chemical vapour deposited diamond was characterized by cathodoluminescence, photoluminescence, Raman spectroscopy and thermally stimulated currents. Then, suitable samples were selected and used to fabricate photoconductive single-pixel and 2D array devices by evaporating metal contacts on the growth surface. The electro-optical characterization of the devices was carried out in a wide spectral region, ranging from 120 to 2400 nm. A deuterium lamp and a 0.5 m vacuum monochromator were used to measure the detector responsivity under continuous monochromatic irradiation in the 120–250 nm spectral range, while an optical parametric oscillator tunable laser producing 5 ns pulses was used as light source from 210 up to 2400 nm. Time response, signal-to-noise ratio, responsivity and visible rejection factor were evaluated and the results are hereafter summarized.

Polycrystalline (pCVD) and single crystal (scCVD) diamond films grown from Chemical Vapour Deposition (CVD), if sufficiently pure at Raman analysis, are very good materials for beam or flux monitors inside accelerators or nuclear reactors. This is because they are very hard to damage in high radiation fields and very resistant to high temperatures. Films of pCVD diamond are, however, not so good as spectroscopy detectors due to inhomogeneities induced by their growth in grains with the consequent presence of grain boundaries which worsen their energy resolution. The latter can be significantly improved by growing scCVD diamond films onto HPHT synthetic diamond substrates. We have shown that it is possible to measure the density of defects inside diamond specimens using as probes suitable penetrating nuclear radiations. With the preliminary results reported here we'll show that, bombarding CVD diamond films grown at Roma 'Tor Vergata' with energetic protons and 4 He, Li-6 and C-12 ions produced in the accelerators of Catania laboratories, the pulse height defects are higher than those in silicon detectors and likewise well described by a power law in the deposited energy. Furthermore, we'll show that pulse heights for the same particles seem to depend on the duration of the measurement, thus exhibiting a sort of depolarization of the insulator when exposed to the electric voltage which makes it a particle detector. (c) 2006 Elsevier B.V. All rights reserved.

Carrier free paths in Chemical Vapour Deposition (CVD) diamond films depend on the presence of traps, which therefore strongly affect the performance of those CVD diamond based devices which rely on the electronic properties of the material, like radiation detectors. For the same reason, these devices can in turn be used as tools to study carrier dynamics. It is well known that some traps may be saturated by pre-irradiation with ionizing radiation (e.g. β-particles), a process called pumping or priming. Not all traps behave in the same way. Due to the large bandgap of diamond, both shallow (not affected by pumping) and deep traps for electrons and holes may exist. We measured, using 5.5 MeV 241 Am α-particles, the response of high quality CVD diamond based detectors after successive annealing steps performed at selected temperatures. The analisys of the decay of the detector efficency with annealing time at several temperatures allows a quantitative evaluation of the activation energy of these defects. Two main trapping centres connected to the pumping process were found, both related to holes, having activation energies of about 1.6 eV and 1.3 eV respectively.

The performance of detectors based on CVD diamond films strongly depends on the material quality, which, in turn, is extremely sensitive to even slight variations of the deposition conditions. In this work, a careful Raman and photoluminescence (PL) study has been carried out on diamond films grown on Si substrates by microwave plasma CVD under nominally identical deposition conditions, but exhibiting, quite surprisingly, different detection sensitivity. Micro-PL measurements performed on the growth surface and on the cross-section of the samples have shown higher incorporation of Si impurities in films having lower detection performance. Optical microscopy on the nucleation side of such films has evidenced a lower nucleation density, leading to diamond grains of greater size, but also to higher incorporation of Si atoms. Thus, a greater grain size does not necessarily guarantee a higher film quality, if the nucleation density is low. On the basis of these results, the nucleation density is identified as the 'hidden' variable in the growth process of our CVD diamond films, determining, ultimately, their detection sensitivity.

The deposition of diamond films on silicon substrate by MWPECVD is described and microstructural characteristics of the obtained films are reported. The resistive and piezoresistive properties of the diamond-on-silicon films have been measured beyond 200 °C by means of a purposely developed apparatus, and experimental results are reported. The piezoresistive properties at high temperature are exploited in the development of a micromachined pressure sensor capable of operating at up to 350–380 °C. A dedicated signal-conditioning electronic circuit is being designed and its functioning principle is here described.

This article describes a procedure in which polytetrafluoroethylene (PTFE) tape is used as a liner for fitting intracoronally retained, indirect restorations. The minimal thickness of the tape allows complete seating and confirmation of marginal fit of restorations during try-in, yet the tape is tough enough to permit trouble-free removal of the restoration afterward. Protection against inadvertent loss of the restoration can be gained if a knot is placed close to the occlusal surface of the restoration prior to its removal.

Il presente lavoro riporta le prime considerazioni sugli effetti del terremoto del 6 Aprile 2009 e del successivo sciame sismico in alcune località in prossimità de L’Aquila da parte dei tecnici del Servizio Geologico, Sismico e dei Suoli della Regione Emilia-Romagna coadiuvati dall’intervento volontario di esperti delle Università di Bologna, Ferrara e Parma. L’attività condotta consiste nello svolgimento di sopralluoghi finalizzati alle valutazioni di agibilità strutturale di edifici di civile abitazione tramite l’impiego della scheda di primo livello AeDES. Nell’articolo si focalizza l’attenzione sugli edifici in muratura che risultano essere, in particolare quelli più vecchi, le strutture maggiormente danneggiate. Si descrivono il comportamento sismico e i danni più frequenti delle tipologie ricorrenti di muratura nell’area analizzata, tra cui la muratura di pietra grezza non lavorata a tessitura sub-orizzontale, e quella in blocchi di calcestruzzo e corsi di malta di notevole spessore con solai e coperture di latero-cemento. Sulla base dei sopralluoghi effettuati, è stato possibile individuare quattro tipologie di dissesto: disgregazione del materiale, ribaltamento fuori dal piano, crisi per presso-flessione fuori dal piano, crisi per presso-flessione o taglio nel piano. Viene inoltre esaminato il comportamento di edifici con interventi di consolidamento, tra cui l’utilizzo di intonaci armati e catene. Infine si riportano alcune osservazioni sugli edifici di culto.

In order to evaluate the charge collection efficiency (CCE) profile of single-crystal diamond devices based on a p-type/intrinsic/metal configuration, a lateral Ion Beam Induced Charge (IBIC) analysis was performed over their cleaved cross sections using a 2 MeV proton microbeam. CCE profiles in the depth direction were extracted from the cross-sectional maps at variable bias voltage. IBIC spectra relevant to the depletion region extending beneath the frontal Schottky electrode show a 100% CCE, with a spectral resolution of about 1.5%. The dependence of the width of the high efficiency region from applied bias voltage allows the constant residual doping concentration of the active region to be evaluated. The region where the electric field is absent shows an exponentially decreasing CCE profile, from which it is possible to estimate the diffusion length of the minority carriers by means of a drift–diffusion model. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Microwave CVD diamond films with very high particle detection efficiency have been obtained using a NIRIM-type reactor. The efficiency and charge collection distance (CCD) of nuclear particle detectors based on these films have been systematically studied as a function both of the methane contents in the growth gas mixture and of the film thickness. In particular, the effects of pre-irradiation with β-particles (pumping) have been thoroughly studied. The detector response to 5.5 MeV α particles was studied using a 241 Am source. Both efficiency and CCD behave in a markedly different way in the as-grown and pumped states, the effect of pumping being strongly dependent on film thickness. These behaviors are analyzed, taking into account the polycrystalline nature of CVD diamond films, in the framework of a recently proposed model [Appl. Phys. Lett. 75 (1999) 3216] discussing the role of in-grain defects and grain boundaries in determining the charge collection spectra of diamond films in the normal and pumped states. Experimental data are found to agree with what is expected from the model. The influence of pumping on the detector resolution is also discussed.

The in-plane (δσab(T,H)) and out-of-plane (δσc(T,H)) components of the magnetoconductivity tensor of Bi2Sr2CaCu2O8+x films have been simultaneously measured in magnetic fields parallel to the film conducting planes (B⩽1 T ) . A negative c-axis magnetoresistance is measured for the first time in this geometry. Both δσab and δσc are well described by the fluctuation theory in the temperature range Tc

Diamond based particle detectors were built up using high quality diamond films grown by microwave chemical vapor deposition (CVD). The efficiency (η) and charge collection distance (CCD) of such devices were tested by a 5.5 Mev 241Am α-particle source. Their response times were then carefully investigated both in the as-grown normal state and after irradiation with β-particles for approximately 60 h, in order to bring the detectors in the so called pumped state. A drastic change in the time evolution, the signal amplitude and the symmetry of the pulse shapes recorded with positive and negative polarization of the detector is observed as soon as the priming procedure takes place. This behavior is explained in the framework of a model in which a trapping–detrapping mechanism for CVD diamond is accounted for. Two different kinds of trapping centers for electrons and holes are proposed as the limiting factor in the diamond detection performance. A very good agreement between the simulation and the experimental pulse shapes is observed, thus allowing a better understanding of the priming procedure and the possible identification of the crystal defects limiting the efficiency of diamond based particle detectors.

A systematic investigation on the influence of metal–diamond interfaces on the electro-optical properties and on the UV response of CVD diamond photo-detectors was carried out in order to identify the optimal electric contacts maximizing the performance. To this purpose, a set of four nearly identical diamond samples has been grown using the microwave plasma enhanced CVD technique. Micro-Raman spectroscopy and photoluminescence have been utilized to assess their quality. Interdigitated planar contacts have been photolithographically deposited on each sample, using different layered metals. In particular, titanium–gold, chromium–gold, aluminum–gold and gold were selected. The performance of these detectors has been investigated under steady photon irradiation in the 120–300-nm wavelength range. The experimental results have been compared and discussed with respect to I–V characteristics, dark current levels, signal-to-noise ratio, spectral response and time response.