A High Dynamic Range ASIC for Time of Flight PET with monolithic crystals

The HRFlexToT is a 16-channel ASIC for SiPM anode readout designed for Positron Emission Tomography (PET) applications that features high dynamic range (>8 bits), low input impedance, common cathode connection, high speed and low power (~3.5 mW/ch). The ASIC has been manufactured using XFAB 0.18 mm CMOS technology. The main characteristics of the HRFlexToT, compared to its predecessor, are a new energy measurement readout providing a linear Time Over Threshold (ToT) with an extended dynamic range, lower power consumption and better timing response. Initial measurements show a linearity error below 3%. Single Photon Time Resolution (SPTR) measurements performed using a Hamamatsu MPPC S13360-3050CS (3x3 mm2 pixel, 50 umm cell) shows 30% improvement with respect to the previous version of the ASIC, setting this specification in the order of 141 ps FWHM and reducing 3 times power consumption. It is important to highlight that an SPTR of 141 ps FWHM is, according to the best of our knowledge, the best resolution achieved so far for this sensor. Coincidence Time Resolution (CTR) measurements are expected to be performed during 2018

Study of cosmogenic activation above ground for the DarkSide-20k experiment

The activation of materials due to exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k, currently under construction at the Laboratori Nazionali del Gran Sasso, is a direct detection experiment for galactic dark matter particles, using a two-phase liquid-argon Time Projection Chamber (TPC) filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Despite the outstanding capability of discriminating / background in argon TPCs, this background must be considered because of induced dead time or accidental coincidences mimicking dark-matter signals and it is relevant for low-threshold electron-counting measurements. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the experiment has been estimated to set requirements and procedures during preparation of the experiment and to check that it is not dominant over primordial radioactivity; particular attention has been paid to the activation of the 120 t of UAr used in DarkSide-20k. Expected exposures above ground and production rates, either measured or calculated, have been considered in detail. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. The activity of 39Ar induced during extraction, purification and transport on surface is evaluated to be 2.8% of the activity measured in UAr by DarkSide-50 experiment, which used the same underground source, and thus considered acceptable. Other isotopes in the UAr such as 37Ar and 3H are shown not to be relevant due to short half-life and assumed purification methods

Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel

Dark matter lighter than 10  GeV/c2 encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement. Sensitivity to light dark matter is explored for various potential energy thresholds and background rates. These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino fog for GeV-scale masses and significant sensitivity down to 10  MeV/c2 considering the Migdal effect or interactions with electrons. Requirements for optimizing the detector’s sensitivity are explored, as are potential sensitivity gains from modeling and mitigating spurious electron backgrounds that may dominate the signal at the lowest energies

Development of a solid-phase extraction method for the simultaneous determination of chloroanisoles and chlorophenols in red wine using gas chromatography-tandem mass spectrometry

A procedure for the determination of three chloroanisoles (2,4,6-trichloro, 2,3,4,6-tetrachloro and pentachloroanisol), as well as their precursor chlorophenols (2,4,6-trichloro, 2,3,4,6-tetrachloro and pentachlorophenol), involved in the presence of cork taint in red wine has been developed. Samples, up to 1 l, were concentrated using a 200 mg Oasis HLB solid-phase extraction (SPE) cartridge. Chlorophenols were quantitatively eluted from this sorbent with 3 ml of methanol. Chloroanisoles were mainly recovered in a second fraction of n-hexane (2 ml). Both fractions were combined and mixed with an aqueous solution of sodium bicarbonate and 50 l of acetic anhydride. Chlorophenols were acetylated in the aqueous-methanolic phase and extracted to n-hexane. Chloroanisoles remained unaffected in the n-hexane layer. Both groups of compounds were determined by gas chromatography-tandem mass spectrometry in the same chromatographic analysis. Using a temperature programmable vaporization injector detection limits from 0.2 to 2.4 ng l -1, below their sensorial threshold level in red wine, were obtained for all compounds. Average recoveries higher than 80% and acceptable precision were achieved using red wine samples spiked with the analytes at different concentration levels. © 2005 Elsevier B.V. All rights reserved

Phase 1 upgrade of the CMS Drift Tubes Read-Out system

In order to cope with up to a factor 2 nominal LHC luminosity, the second level of the readout system of the CMS Drift Tubes (DT) electronics needs to be redesigned to minimize event processing time and remove present bottlenecks. The uROS boards are uTCA modules, which include a Xilinx Virtex-7 FPGA and equip up to 6 12-channel optical receivers of the 240 Mbps input links. Each board collects the information from up to 72 input links (3 DT sectors), requiring a total of 25 boards. The design of the system and the first validation tests will be described.ation tests will be described

SERS chiral recognition and quantification of enantiomers through cyclodextrin supramolecular complexation

We introduce here a simple approach in which a cyclodextrin, functionalized with thiols in the narrower rim, is assembled onto the silver surface of a SERS platform composed of polystyrene beads coated with silver nanoparticles. Trapping properties of the fabricated sensor are demonstrated through the retention of different enantiomers (R,R or/and S,S) of hydrobenzoin (HBZ), a molecule that has not been reported before in SERS because it has no affinity for coinage metal surfaces. Further, selective recognition of each enantiomer and semiquantification of its proportion in a racemic mixture are provided by the analysis of the SERS spectra of the HBZ-cyclodextrin complex, in full agreement with the surface selection rules. Enantioselective sensor: We introduce a simple approach in which a cyclodextrin is assembled onto the silver surface of a SERS platform for chiral recognition of enantiomers (see picture). Trapping properties, chiral discrimination and quantification of the R,R- and S,S-enantiomers of hydrobenzoin by surface-enhanced Raman scattering (SERS) spectroscopy are demonstrated

A European infrastructure for fusion simulations

The Integrated Tokamak Modelling Task Force (ITM-TF) is developing an infrastructure where the validation needs, as being formulated in terms of multi-device data access and detailed physics comparisons aiming for inclusion of synthetic diagnostics in the simulation chain, are key components. A device independent approach to data transport and a standardized approach to data management (data structures, naming, and access) is being developed in order to allow cross validation between different fusion devices using a single toolset. The effort is focused on ITER plasmas and ITER scenario development on current fusion device. The modeling tools are, however, aimed for general use and can be promoted in other areas of modelling as well. Extensive work has already gone into the development of standardized descriptions of the data (Consistent Physical Objects) providing initial steps towards a complete fusion modelling ontology. The longer term aim is a complete simulation platform which is expected to last and be extended in different ways for the coming 30 years. The technical underpinning is therefore of vital importance. In particular, the platform needs to be extensible and open-ended to be able to take full advantage of not only today\u27s most advanced technologies but also be able to marshal future developments. A full level comprehensive prediction of ITER physics rapidly becomes expensive in terms of computing resources and may cover a range of computing paradigms. The simulation framework therefore needs to be able to use both grid and HPC computing facilities. Hence, data access and code coupling technologies are required to be available for a heterogeneous, possibly distributed, environment. The developments in this area are pursued in a separate project - EUFORIA (EU Fusion for ITER Applications). The current status of ITM-TF and EUFORIA is presented and discussed. \ua9 2010 IEEE