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DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6 $$\times $$ ×  6 $$\times $$ ×  6 m$$^3$$ 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Ž .Ž . We evaluated the electrochemical deposition of Pb II onto Fractured Vitreous Carbon FVC electrodes from solutions Ž . containing very low concentrations of lead in different electrolytes sulfate or chloride . To examine how the FVC surface state influences the lead deposition efficiency, the electrodes were subjected to different electrochemical pretreatments prior Ž . to the actual deposition process. The FVC electrode was used as a representative model of the vitreous carbon VC bulk, avoiding the polishing procedure that could change the surface. Electrochemical pretreatment was carried out by cyclic voltammetry in electrolytes containing chloride or nitrate anions and in some cases, ferrocyanide. Before and after the Ž . electrochemical pretreatment, the electrode surface morphology was assessed using Atomic Force Microscopy AFM Ž . imaging. The quantity of lead deposited on the FVC electrode surface lead deposition efficiency in each experiment was estimated from the charge under the lead anodic, dissolution peak. Electrochemical pretreatment of electrodes in chloride or nitrate electrolytic baths consistently reduced the lead deposition efficiency. A detailed analysis, correlating lead deposition efficiencies to surface roughness and fractal dimension of the freshly prepared and electrochemically pretreated FVC electrodes, indicated that the decrease in efficiency corresponded to the change in electrode surface geometry. The greater efficiency of lead deposition observed in the chloride-containing electrolyte was due to the interaction between chloride and deposited lead rather than a chloride interaction with the FVC substrate. q

The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, U.S.A. The ProtoDUNE-SP detector incorporates full-size components as designed for DUNE and has an active volume of 7 × 6 × 7.2 m3. The H4 beam delivers incident particles with well-measured momenta and high-purity particle identification. ProtoDUNE-SP's successful operation between 2018 and 2020 demonstrates the effectiveness of the single-phase far detector design. This paper describes the design, construction, assembly and operation of the detector components.

The ultrastructure of human tooth enamel from a patient diagnosed to have amelogenesis imperfecta (AI) was investigated using atomic force microscopy (AFM) and compared with normal human tooth enamel. AI is a hereditary defect of dental enamel in which the enamel is deficient in either quality or quantity. Tissue-specific proteins, especially amelogenins, have been postulated to play a central role in amelogenesis. The secondary structure of amelogenin has been assigned an important role in directing the architecture of hydroxyapatite (HA) enamel crystallites and an alteration of the secondary structure of amelogenin is expected to result in an altered architecture of the mineral phase in human enamel. Previous studies have shown that the human amelogenin gene encodes for a mutant protein in which a conserved Pro is mutated to a Thr residue (Pro-->Thr); such a mutation should be expected to cause a disoriented pattern of the mineral phase in enamel. AFM results presented for the AI tooth enamel clearly demonstrate that the apatite crystal morphology in AI tooth enamel is perturbed in the diseased state; this might result from a defective synthesis of the extracellular matrix proteins, e.g. amelogenin, by the ameloblasts.

Development of new electrodes is the key element for the improvement of the high rate Resistive Plate Chambers (RPC). In the particular case of resistive electrodes, the fabrication of these devices is a challenging problem from a material science point of view. The combination of resistivity, permittivity and stability requirements is really hard to satisfy for any known material. Respecting this, several materials have been found to be suitable for fabrication of resistive plates. In this work, we have carried out electrical characterizations of some of these materials that are currently used in RPCs or are solid candidates to be used as resistive plates for high rate RPCs. As a result, we have found strong evidences that ion conduction processes under moderate to high electric fields are able to drift high amounts of charge which are crucial to understand the degradation nature of the involved processes.