Time-of-flight (ToF) performances of large area diamond detectors based on polycrystalline samples of dimensions 20 mm × 20 mm and thickness of 0.3 mm are presented. The devices that feature ...segmented Cr/Au electrodes in a sandwich configuration were irradiated with a heavy ions 197Au beam of 1 GeV u−1 showing, when mounted with a separation distance of 2 cm, a ToF resolution σ¯ of 37.5 ps averaged on 16 strip pairs. When ToF measurements were performed over a particle path of 30 m, a resolution σ of 45 ps was achieved. The detectors were mounted on high-vacuum compatible printed circuit boards (PCBs) with integrated processing electronics. This is the first time that ToF measurements have been performed using integrated electronics with such a large separation distance between the diamond detectors.
We present the first determination of the energy-dependent amplitudes of N⁎ resonances extracted from their decay in KΛ pairs in p+p→pK+Λ reactions. A combined Partial Wave Analysis of seven data ...samples with exclusively reconstructed p+p→pK+Λ events measured by the COSY-TOF, DISTO, FOPI and HADES Collaborations in fixed target experiments at kinetic energies between 2.14 to 3.5 GeV is used to determine the amplitude of the resonant and non-resonant contributions into the associated strangeness final state. The contribution of seven N⁎ resonances with masses between 1650 MeV/c2 and 1900 MeV/c2 for an excess energy between 0 and 600 MeV has been considered. The Σ–p cusp and final state interactions for the p–Λ channel are also included as coherent contributions in the PWA. The N⁎ contribution is found to be dominant with respect to the phase space emission of the pKΛ+ final state at all energies demonstrating the important role played by both N⁎ and interference effects in hadron–hadron collisions.
There has been a growing interest in traditional dairy (such as raw milk cheeses) and meat products, in recent years. However, these products are suitable and nutrient medium and may be easily ...contaminated by microorganisms such as
Enterobacteriaceae
.
Enterobacteriaceae
are considered to be the indicator bacteria for microbiological quality of food and hygiene status of a production process. Additionally, the food contaminated by
Enterobacteriaceae
poses a microbiological risk for consumers. In fact, the contamination of raw milk and meat by
Enterobacteriaceae
amid manufacturing may easily occur from various environmental sources, and this group of bacteria is frequently detected in dairy and meat products. Therefore, monitoring the microbiological quality of the used raw material and maintaining high standards of hygiene in the production process are mandatory for a high quality of traditional products and the safety of the potential consumers. The goal of this review is to present the most recent survey on
Enterobacteriaceae
growth, number, and distribution in raw milk cheeses and meat, as well as to discuss the sources of contamination and methods of control.
Key points
•
Enterobacteriaceae: role and importance in milk and meat products, EU legal regulations
•
Dynamics, distribution, and survival of Enterobacteriaceae in milk and meat
•
Mechanisms of control of Enterobacteriaceae in dairy products
The development of CVD grown single-crystal Diamond-on-Iridium (DOI) sensors for charged-particle detection in hadrons and nuclei physics research is reviewed. A variety of samples grown at the ...University of Augsburg has been investigated with α and β sources in the laboratory, swift ions from the heavy-ion synchrotron SIS in Darmstadt, and relativistic protons from the COoler-SYnchrotron COSY in Jülich. The results obtained by means of I-E(V) studies, transient-current techniques (TCT), α-spectroscopy, and heavy-ion time-of-flight (ToF) measurements are compared to those of commercially available polycrystalline and homoepitaxial single crystal CVD diamond sensors of electronic grade quality.
In many aspects, the performance of DOI sensors was found quite similar to that of homoepitaxial counters, and in any case far superior to that of polycrystalline detectors. Under single-carrier drift conditions, the CCE and energy resolution (δE/E) for holes reached levels CCEh > 95% and δE/Eh ~ 0.3%, respectively, which correspond to values of the Schubweg wh,e well above the detector thickness. In contrast, the CCEe for electrons was typically lower than ~40%, leading to appreciable reduction of the detection efficiency in the dual-carrier drift mode (CCE ~ 60%), which characterizes the experiments with swift heavy ions and high-energy particles. We measured transport parameters comparable to those of homoepitaxial devices: μ0h ~ 3080–1756 and μ0e ~ 2276–1150 cm2/Vs, vsath ~ (1.7–1.4) ∗ 107 and vsate ~ (1.5–1.0) ∗ 107 cm/s, as well as intrinsic time resolutions σi ~ 15 ps. It is shown, that substantial improvements have been achieved in recent years, albeit reproducibility and the understanding of the reduced electron collection remain challenging issues.
Prime novelty: Comprehensive electrical characterization of intrinsic single-crystal CVD Diamond-On-Iridium sensors produced at the University of Augsburg and their classification into the range of commercial electronic grade polycrystalline and homoepitaxial diamond sensors supplied by Element Six.
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•Comprehensive study exploring detector properties and perspectives of CVD Diamond-on-Iridium (DOI) produced in Augsburg.•DOI sensors are compared with commercial poly (PCD) and single-crystal CVD-diamond (SCD) samples supplied by Element Six.•The excellent drift and collection properties at h-drift enable particle timing and spectroscopy.•DOI sensors are clearly outperforming PCD counters.•The results indicate a high potential of heteroepitaxial diamond grown on Ir/YSZ/Si(001) for large-area detector systems.
Abstract The Super-FRS at the FAIR accelerator complex will adopt Chemical Vapor Deposition diamond detectors as radiation-hard particle rate counters. Their role will be to monitor the beam ...transmission for beams with ions rates up to 10 7 ions/spill and to calibrate the other beam diagnostics devices that are in duty at higher beam intensities. The target vacuum chamber of the Super-FRS hosts a 7 × 7 mm 2 single crystal diamond and a 25 × 25 mm 2 polycrystalline diamond: they are required to detect crossing particles with high efficiency (> 98%) in the case of heavy ion species (Ar to U), and to stand for several years in an environment in which they can potentially accumulate a dose of a few MGy per year. Laboratory measurements and beam test campaigns were arranged in the past years for the validation of the proposed sensors, in particular for the case of the polycrystalline technology. Here we report the outcome of the irradiation of a sensor based on a 20 × 20 mm 2 polycrystalline diamond produced by Element Six, with high intensity 1 GeV/nucleon Pb and U beams at GSI (Darmstadt). The detector signal shape characteristics and the ion counting efficiency have been monitored by interleaving periods of low ions rates, to evaluate possible damages or performance degradation during and after a total bombardment of about 6 × 10 11 heavy ions.
Charged particle detectors based on thin single crystal diamond films (3.0×3.0×0.09mm3) grown by chemical vapour deposition (CVD) technique are developed at Ruđer Bošković Institute and low field ...mobility, transit time and saturation velocity, measured by using a 210Po alpha source in vacuum at room temperature, are presented.
The comparison of the charge transport properties obtained by time of flight (ToF) technique between detectors based on the same diamond samples, but with different metallization of the electrodes (Au and Al, 100nm thick), and commercially purchased diamond detectors is performed.
The fabricated diamond sensors showed a spectroscopic resolution of up to 1%, mobility up to 1808±16 and 1914±71cm2/Vs for electrons and holes respectively and carrier transit time below 2ns for an applied electric field of 17.8×103V/cm. Results also show variations of the charge transport properties according to the electrode metallization used and the different modality at which the detectors are irradiated.
•- Possibility of using the diamond sensors also under condition of illumination and in air.•- Variation of the electronic properties of the charge carriers according to the different mode of irradiation.•- Variation of the electronic properties of the charge carriers according to the type of electric contacts adopted.•- Thin sensors report better spectroscopic performances compared to devices made of thick diamond samples.
We investigated the merits of different event parameters in the identification of Light Charged Particles (LCPs) with CsI(Tl) scintillators read out by photodiodes at high incident energy (400 ...MeV/u). This investigation is made possible by digital signal processing the output signals. As in the conventional analogue case, the digitized signals allow the discrimination of light charged particles by computing the fast and slow components. In addition other identification parameters as the rise time of the output pulses of the CsI(Tl) come out nearly for free. Aim of this paper is the investigation of novel identification plots and the probe of their merits, in particular at relativistic energies.
In the ASY-EOS experiment flows of neutrons and light charged particles were measured for 197Au+197Au collisions at 400 MeV/nucleon, in order to investigate the strength of the symmetry term of the ...nuclear equation of state at supra-saturation densities. By comparing the experimental data with the UrQMD transport model predictions, we have extracted a new constraint in agreement with the moderately soft to linear density dependence obtained in the former analysis on FOPI-LAND data, but reducing the associated uncertainty by a factor ∼ 2.
The present work reports on a long-term irradiation test performed on a 0.3-mm thick polycrystalline diamond detector prototype. The device, biased at 300 V, was continuously irradiated for about ...60 h by using a 12C beam at 62 MeV/nucl. at the LNS-INFN Cyclotron facility in Catania. An ionization chamber, calibrated using a single crystal diamond detector, was used to evaluate the total absorbed dose in the diamond detector under study. Data analysis carried out on recorded oscilloscope waveforms shows no significant variation of the signal properties in terms of amplitude, slope and charge after exposure to an integrated flux of 6.2⋅ 1013 ions/cm2. The results indicate that a polycrystalline diamond detector can be used for calibrating intensity monitors at the future superconducting fragment separator Super-FRS at FAIR (Darmstadt).
•No change observed in the signal proprieties of an irradiated pcCVD diamond material•Diamond detectors as precise intensity monitors with heavy ion beams•Survival of a pcCVD diamond detector after long-term beam current calibrations
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