Search

The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reactor, and has collected a 3.7 kg-day exposure using a CCD detector array sensitive to an $\sim$1 keV threshold for the study of coherent neutrino-nucleus elastic scattering. Here we demonstrate the potential of this low-energy neutrino experiment as a probe for physics Beyond the Standard Model, by using the recently published results to constrain two simplified extensions of the Standard Model with light mediators. We compare the new limits with those obtained for the same models using neutrinos from the Spallation Neutron Source. Our new constraints represent the best limits for these simplified models among the experiments searching for CE$\nu$NS for a light vector mediator with mass $M_{Z^{\prime}}, Comment: Accepted for publication in JHEP

Silicon photomultipliers (SiPMs) are novel optoelectronic devices of solid-state technology. They have several advantages with respect to the traditional photomultiplier tubes, such as a superior Photon Detection Efficiency and time resolution. They are compact, mechanically robust, insensitive to magnetic fields and require a relatively low bias voltage, which are attractive characteristics for space-borne applications. In this work, we present the design of an Analog Front-End (AFE) Electronics for SiPMs, optimized for ultra low-light space-borne applications. The system is composed by a transimpedance amplifier and a high speed comparator with differential LVDS output for data transmission. Design considerations are discussed and the fabrication of a prototype is presented, along with analog and digital characterization measurements performed on it.

The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses low-noise fully depleted charge-coupled devices (CCDs) with the goal of measuring low-energy recoils from coherent elastic scattering (CE$\nu$NS) of reactor antineutrinos with silicon nuclei and testing nonstandard neutrino interactions (NSI). We report here the first results of the detector array deployed in 2016, considering an active mass 47.6 g (8 CCDs), which is operating at a distance of 30 m from the core of the Angra 2 nuclear reactor, with a thermal power of 3.8 GW. A search for neutrino events is performed by comparing data collected with reactor on (2.1 kg-day) and reactor off (1.6 kg-day). The results show no excess in the reactor-on data, reaching the world record sensitivity down to recoil energies of about 1 keV (0.1 keV electron-equivalent). A 95% confidence level limit for new physics is established at an event rate of 40 times the one expected from the standard model at this energy scale. The results presented here provide a new window to low-energy neutrino physics, allowing one to explore for the first time the energies accessible through the low threshold of CCDs. They will lead to new constrains on NSI from the CE$\nu$NS of antineutrinos from nuclear reactors., Comment: Updated to match the version accepted for publication in Physical Review D

The LabOSat collaboration (acronym for “Laboratory On a Satellite”) aims to increase the Technology Readiness Level (TRL) of electronic devices and components for space-borne applications. We have developed a single-board electronic platform which is able to operate in space conditions. This board harbors Devices Under Test and performs electric experiments on them. Since 2014, we have participated in six satellite missions (Satellogic small satellites) in Low Earth Orbits, in which we studied the performance of electronic devices such as resistive switching memories and dosimeters based on field-effect transistors. In this work we present our efforts to increase the TRL of Silicon Photomultipliers (SiPMs). In early 2019 we have integrated four 6-mm SiPMs into a 40-kg satellite to study their performance in space. Each SiPM was encapsulated into individual light-tight aluminum housings, which included LEDs for excitation. The SiPMs and the LEDs are operated in DC current mode. Besides the SiPMs current and voltage measurements, the experiment also collects telemetry parameters like temperature, timestamp and orbital position. Fil: Barella, Mariano. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; Argentina Fil: Burroni, Tomás Ignacio. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina Fil: Carsen, Irina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina Fil: Far, Mónica. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina Fil: Ferreira Chase, Tomás Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina Fil: Finazzi, Lucas. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Golmar, Federico. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gomez Marlasca, Fernando. Comisión Nacional de Energía Atómica; Argentina Fil: Izraelevitch, Federico Hernán. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Levy, Pablo. Comisión Nacional de Energía Atómica; Argentina Fil: Sanca, Gabriel. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina

We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30 eV$c^{-2}$ with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter $\kappa$ is competitive with constraints from solar emission, reaching a minimum value of 2.2$\times$$10^{-14}$ at 17 eV$c^{-2}$. These results are the most stringent direct detection constraints on hidden-photon dark matter in the galactic halo with masses 3-12 eV$c^{-2}$ and the first demonstration of direct experimental sensitivity to ionization signals $, Comment: 5 pages, 5 figures

We have measured the ionization efficiency of silicon nuclear recoils with kinetic energy between 1.8 and 20 keV. We bombarded a silicon-drift diode with a neutron beam to perform an elastic-scattering experiment. A broad-energy neutron spectrum was used and the nuclear recoil energy was reconstructed using a measurement of the time of flight and scattering angle of the scattered neutron. The overall trend of the results of this work is well described by the theory of Lindhard et al. above 4 keV of recoil energy. Below this energy, the presented data shows a deviation from the model. The data indicates a faster drop than the theory prediction at low energies. Fil: Izraelevitch, Federico Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Amidei, D.. University of Michigan; Estados Unidos Fil: Aprahamian, A.. University of Notre Dame; Estados Unidos Fil: Arcos Olalla, R.. Universidad de Guanajuato; México Fil: Cancelo, Gustavo Indalecio Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Casarella, C.. University of Notre Dame; Estados Unidos Fil: Chavarria, A. E.. University of Chicago; Estados Unidos Fil: Collon, P.. University of Notre Dame; Estados Unidos Fil: Estrada, Juan. Fermi National Accelerator Laboratory; Estados Unidos Fil: Fernández Moroni, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Guardincerri, Yann. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Gutiérrez, G.. Fermi National Accelerator Laboratory; Estados Unidos Fil: Gyurjinyan, A.. University of Notre Dame; Estados Unidos Fil: Kavner, A.. University of Michigan; Estados Unidos Fil: Kilminster, B.. Universitat Zurich; Suiza Fil: Liao, J.. Universitat Zurich; Suiza Fil: Liu, Q.. University of Notre Dame; Estados Unidos Fil: López, M.. Universidad Nacional de Asunción; Paraguay Fil: Molina, J.. Universidad Nacional de Asunción; Paraguay Fil: Privitera, P.. University of Chicago; Estados Unidos Fil: Reyes, M. A.. Universidad de Guanajuato; México Fil: Scarpine, V.. Fermi National Accelerator Laboratory; Estados Unidos Fil: Siegl, K.. University of Notre Dame; Estados Unidos Fil: Smith, M.. University of Notre Dame; Estados Unidos Fil: Strauss, S.. University of Notre Dame; Estados Unidos Fil: Tan, W.. University of Notre Dame; Estados Unidos Fil: Tiffenberg, Javier Sebastian. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Villanueva, L.. Universidad de Guanajuato; México

The CONNIE Experiment (Coherent Neutrino Nucleus Interaction Experiment) is currently collecting reactor neutrino data to search for the undiscovered standard model process of coherent neutrino-nucleus scattering (CNNS). The detector is composed of a silicon target of thick, fully-depleted, low-noise CCD detectors. Results from data collected in 2015 indicate backgrounds are controlled, and allow an estimate of sensitivity to be presented for a larger scale detector. A 2016 upgrade, adding additional target mass, and reducing readout noise, has been performed, increasing the total yield of signal events by a factor of 30, and already yielding science-quality data. Low-energy nuclear calibrations have been performed, enabling calibration down to the device energy threshold. An estimate of the sensitivity expected for measuring the coherent neutrino process is presented. Future prospects with improved detector energy thresholds are estimated.

We report a measurement of the ionization efficiency of silicon nuclei recoiling with sub-keV kinetic energy in the bulk silicon of a charge-coupled device (CCD). Nuclear recoils are produced by low-energy neutrons ($, Comment: 7 pages, 7 figures

We present measurements of radioactive contamination in the high-resistivity silicon charge-coupled devices (CCDs) used by the DAMIC experiment to search for dark matter particles. Novel analysis methods, which exploit the unique spatial resolution of CCDs, were developed to identify $\alpha$ and $\beta$ particles. Uranium and thorium contamination in the CCD bulk was measured through $\alpha$ spectroscopy, with an upper limit on the $^{238}$U ($^{232}$Th) decay rate of 5 (15) kg$^{-1}$ d$^{-1}$ at 95% CL. We also searched for pairs of spatially correlated electron tracks separated in time by up to tens of days, as expected from $^{32}$Si-$^{32}$P or $^{210}$Pb-$^{210}$Bi sequences of $\beta$ decays. The decay rate of $^{32}$Si was found to be $80^{+110}_{-65}$ kg$^{-1}$ d$^{-1}$ (95% CI). An upper limit of $\sim$35 kg$^{-1}$ d$^{-1}$ (95% CL) on the $^{210}$Pb decay rate was obtained independently by $\alpha$ spectroscopy and the $\beta$ decay sequence search. These levels of radioactive contamination are sufficiently low for the successful operation of CCDs in the forthcoming 100 g DAMIC detector., Comment: 18 pages, 20 figures

We introduce the fully-depleted charge-coupled device (CCD) as a particle detector. We demonstrate its low energy threshold operation, capable of detecting ionizing energy depositions in a single pixel down to 50 eVee. We present results of energy calibrations from 0.3 keVee to 60 keVee, showing that the CCD is a fully active detector with uniform energy response throughout the silicon target, good resolution (Fano ~0.16), and remarkable linear response to electron energy depositions. We show the capability of the CCD to localize the depth of particle interactions within the silicon target. We discuss the mode of operation and unique imaging capabilities of the CCD, and how they may be exploited to characterize and suppress backgrounds. We present the first results from the deployment of 250 um thick CCDs in SNOLAB, a prototype for the upcoming DAMIC100. DAMIC100 will have a target mass of 0.1 kg and should be able to directly test the CDMS-Si signal within a year of operation., 13 pages, 12 figures, proceedings prepared for 13th International Conference on Topics in Astroparticle and Underground Physics (TAUP2013)

DAMIC (Dark Matter in CCDs) is an experiment searching for dark matter particles employing fully-depleted charge-coupled devices. Using the bulk silicon which composes the detector as target, we expect to observe coherent WIMP-nucleus elastic scattering. Although located in the SNOLAB laboratory, 2 km below the surface, the CCDs are not completely free of radioactive contamination, in particular coming from radon daughters or from the detector itself. We present novel techniques for the measurement of the radioactive contamination in the bulk silicon and on the surface of DAMIC CCDs. Limits on the Uranium and Thorium contamination as well as on the cosmogenic isotope 32 Si, intrinsically present on the detector, were performed. We have obtained upper limits on the 238 TJ (232 Th) decay rate of 5 (15) kg_1 d_1 at 95% CL. Pairs of spatially correlated electron tracks expected from 32 Si-32 P and 210 Pb-210 Bi beta decays were also measured. We have found a decay rate of 80+l10 -65 kg_1 d_1 for 32 Si and an upper limit of - 35 kg-1 d-1 for 210 Pb, both at 95% CL.