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We present the development of a Skipper Charge-Coupled Device (CCD) focal plane prototype for the SOAR Telescope Integral Field Spectrograph (SIFS). This mosaic focal plane consists of four 6k $\times$ 1k, 15 $\mu$m pixel Skipper CCDs mounted inside a vacuum dewar. We describe the process of packaging the CCDs so that they can be easily tested, transported, and installed in a mosaic focal plane. We characterize the performance of $\sim 650 \mu$m thick, fully-depleted engineering-grade Skipper CCDs in preparation for performing similar characterization tests on science-grade Skipper CCDs which will be thinned to 250$\mu$m and backside processed with an antireflective coating. We achieve a single-sample readout noise of $4.5 e^{-} rms/pix$ for the best performing amplifiers and sub-electron resolution (photon counting capabilities) with readout noise $\sigma \sim 0.16 e^{-} rms/pix$ from 800 measurements of the charge in each pixel. We describe the design and construction of the Skipper CCD focal plane and provide details about the synchronized readout electronics system that will be implemented to simultaneously read 16 amplifiers from the four Skipper CCDs (4-amplifiers per detector). Finally, we outline future plans for laboratory testing, installation, commissioning, and science verification of our Skipper CCD focal plane.

This article proposes a new technique to reduce the readout noise in charge-coupled devices (CCDs). The objective is to minimize the common noise between the channels. This noise is either induced by the readout electronics or by the environment, and it could be present in small (single CCD and a few channels) or large systems (dozens of CCDs and hundreds of channels). By interleaving the video signals, we show that it is possible to reduce the readout noise by around 50% without sacrificing output channels at the expense of a moderate increase of the readout time, which is less compared with other techniques. Up until now, similar approaches have used half of the output stages only for noise measurement doubling the total readout time of the sensor. Simulations and experimental results are presented to validate the proposed approach. Moreover, the technique is measured using a Skipper CCD, and its operation is validated together with the ability of the Skipper sensor for nondestructively reading, several times, the same pixel charge. With the combination of both techniques, we achieve deep subelectron readout noise levels (0.1 e−).

In this article, we present the measurements and a physically motivated model for the transport and diffusion of small charge packets in the bulk of thick high-resistivity charge-coupled devices (CCDs). We use a novel technique to measure the lateral spread of the charge as a function of the ionization depth in the silicon bulk. Measurements from CCDs, currently being used in several scientific instruments, are shown and used to validate the new mathematical algorithm that extends the current modeling of the diffusion of the charge carriers in silicon before being collected by the pixel potential wells.

This article provides a practical design methodology to calculate an optimal filter for noise reduction in the readout of charge‐coupled devices (CCDs) taking into account the charge transfer and feedthroughs due to capacitive coupling in the CCD. A detailed analysis of the dynamics of the video signal and charge transfer is presented, including the circuital modeling of the output stage of the CCD and the dynamics of the electronics in the video chain before the analog‐to‐digital (AD) converter. This model is used to compute an optimal filter that minimizes the variance of the pixel noise and uses the samples of the charge transfer, before the charge is fully settled. This is necessary to enhance the performance of previous results that also use optimal filters but do not use the transition samples, while also reducing the pixel readout time, resulting in faster readouts. As a proof of concept for the optimal filter, we present novel experimental results using a Skipper CCD, which has a floating sense node that allows to measure the charge packet an arbitrary number of times. However, this technique can be applied to any CCD that has a readout system that digitally samples the video signal. Fil: Chierchie, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Fernández Moroni, Guillermo. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Querejeta Simbeni, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Stefanazzi, Leandro. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Paolini, Eduardo Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina Fil: Sofo Haro, Miguel Francisco. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cancelo, Gustavo Indalecio. Fermi National Accelerator Laboratory; Estados Unidos Fil: Estrada, Juan. Fermi National Accelerator Laboratory; Estados Unidos

Image sensors with nondestructive charge readout provide single-photon or single-electron sensitivity, but at the cost of long readout times. We present a smart readout technique to allow the use of these sensors in visible light and other applications that require faster readout times. The method optimizes the readout noise and time by changing the number of times pixels are read out either statically, by defining an arbitrary number of regions of interest in the array, or dynamically, depending on the charge or energy of interest in the pixel. This technique is tested in a Skipper CCD showing that it is possible to obtain deep subelectron noise, and therefore, high resolution of quantized charge, while dynamically changing the readout noise of the sensor. These faster, low noise readout techniques show that the skipper CCD is a competitive technology even where other technologies such as electron multiplier charge coupled devices, silicon photo multipliers, etc. are currently used. This technique could allow skipper CCDs to benefit new astronomical instruments, quantum imaging, exoplanet search and study, and quantum metrology. Fil: Chierchie, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Fernández Moroni, Guillermo. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Stefanazzi, Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Paolini, Eduardo Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Tiffenberg, Javier Sebastian. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Estrada, Juan. Fermi National Accelerator Laboratory; Estados Unidos Fil: Cancelo, Gustavo Indalecio. Fermi National Accelerator Laboratory; Estados Unidos Fil: Uemura, Sho. Universitat Tel Aviv; Israel

Low noise CCDs fully-depleted up to 675 micrometers have been identified as a unique tool for Dark Matter searches and low energy neutrino physics. The charge collection efficiency (CCE) for these detectors is a critical parameter for the performance of future experiments. We present here a new technique to characterize CCE in back-illuminated CCDs based on soft X-rays. This technique is used to characterize two different detector designs. The results demonstrate the importance of the backside processing for detection near threshold, showing that a recombination layer of a few microns significantly distorts the low energy spectrum. The studies demonstrate that the region of partial charge collection can be reduced to less than 1 micrometer thickness with adequate backside processing.

The skipper CCD is a special type of charge coupled device in which the readout noise can be reduced to sub-electron levels by averaging independent measurements of the same charge. Thus the charge in the pixels can be determined by counting the exact number of electrons. The total readout time is proportional to the number of measurements of the charge in each pixel. For some applications this time may be too long; however, researchers usually are interested only on certain region within the matrix of pixels. In this paper we present the development of a smart skipper readout technique that allows the user to specify regions of interest of the CCD matrix where an arbitrary (high) number of measurements of the same charge can taken to obtain the desired noise level, and far less measurements are performed in those regions that are less interesting to the researcher, therefore reducing the total readout time.

This work presents the design of a new optimal filter to reduce the readout noise of CCD sensors. This new filter uses the information from the transfer function of the video signal. Moreover, it incorporates the noise autocorrelation matrix to reduce the effect of weakly stationary noise sources, like the time jitter in sampling. The filter was tested through simulations and compared to the standard CCD reading method known as Double Correlated Sampling (CDS for Correlated Double Sampling), giving better results.

The development of the Skipper-charge-coupled devices (Skipper-CCDs) has been a major technological breakthrough for sensing very weak ionizing particles. The sensor allows to reach the ultimate sensitivity of silicon material as a charge signal sensor by unambiguous determination of the charge signal collected by each cell or pixel, even for single electron–hole pair ionization. Extensive use of the technology was limited by the lack of specific equipment to operate the sensor at the ultimate performance. A simple, single-board Skipper-CCD controller designed by the authors is presented and aimed for the operation of the detector in high sensitivity scientific applications. Our article describes the main components and functionality of the so-called low threshold acquisition controller together with experimental results when connected to a Skipper-CCD sensor. Measurements show unprecedented deep subelectron noise of 0.039 erms−/pix by nondestructively measuring the charge 5000 times in each pixel.

We characterize the response of a novel 250 $\mu$m thick, fully-depleted Skipper Charged-Coupled Device (CCD) to visible/near-infrared light with a focus on potential applications for astronomical observations. We achieve stable, single-electron resolution with readout noise $\sigma \sim 0.18$ e$^{-}$ rms/pix from 400 non-destructive measurements of the charge in each pixel. We verify that the gain derived from photon transfer curve measurements agrees with the gain calculated from the quantized charge of individual electrons to within < 1%. We also perform relative quantum efficiency measurements and demonstrate high relative quantum efficiency at optical/near-infrared wavelengths, as is expected for a thick, fully depleted detector. Finally, we demonstrate the ability to perform multiple non-destructive measurements and achieve sub-electron readout noise over configurable subregions of the detector. This work is the first step toward demonstrating the utility of Skipper CCDs for future astronomical and cosmological applications., Comment: 14 pages, 6 figures, 2 tables

The Skipper-CCDs, a special type of charge-coupled device (CCD) sensor that features sub-electron readout noise levels, was proposed decades ago. However, only in recent years it has been possible to develop large size Skipper-CCDs ensuring stable operation. Their extreme low noise operation makes them suitable for experiments that require low thresholds and high energy resolution, such as dark matter and neutrino interactions detection, and more recently quantum-imaging and astronomy. New experiments are planning to use kilograms of active silicon from Skipper-CCDs as sensitive mass. In this way, they can achieve extremely low detection thresholds and a high probability of particle interaction. However, this approach needs arrays of thousands of Skipper- CCDs operating at the same time imposing challenging requirements. Also, introduction of this technology in astronomy and quantum-imaging applications requires a large number of channels per sensor to speed up the readout. The front-end needs to be redesigned from scratch: it must achieve low noise performance, be simple for easy integration and allow the routing of thousands of channels out of the sensors with minimal connections. This paper presents a detailed analysis of options for the front-end electronics and their noise performance. It describes a novel way of using a dual-slope integrator with minimal components to pile up the charge of consecutive readouts of the same pixel in a concept that we call a multi-slope integrator. This reduces drastically the output bandwidth, simplifying the wiring and the warm electronics. These proposals will allow the generation of new scientific instruments based on Skippers-CCD arrays.

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

Skipper-CCD can achieve deep sub-electron readout noise making possible the absolute determination of the exact number of ionized electrons in a large range, from 0 to above 1900 electrons. In this work we present a novel technique that exploits this unique capability to allow self-calibration and the ultimate determination of silicon properties. We performed an absolute measurement of the variance and the mean number of the charge distribution produced by $^{55}$Fe X-rays, getting a Fano factor absolute measurement in Si at 123K and 5.9 keV. A value of 0.119 $\pm$ 0.002 was found and the electron-hole pair creation energy was determined to be (3.749 $\pm$ 0.001) eV. This technology opens the opportunity for direct measurements of the Fano factor at low energies., six pages, five figures, three tables, one equation

En los últimos años, la incorporación de nuevas tecnologías por parte de las empresas y el gran volumen de datos generados por estas ha motivado la paulatina incorporación de herramientas que permitan análisis de estos datos para la obtención y utilización de información que pueda mejorar la gestión dentro de las mismas organizaciones. Este nuevo escenario de gran cantidad de datos disponibles que potencialmente puede ser utilizado para mejorar la toma de decisiones en las empresas es llamado Big Data. La adaptación de las empresas a este nuevo escenario es fundamental para generar ventajas competitivas respecto a sus competidores. Este artículo trata de establecer el efecto de las “5V’s” (volumen, variedad, velocidad, valor y veracidad) de Big Data en el proceso de toma de decisiones de ejecutivos de diferentes niveles jerárquicos utilizando en una cooperativa de venta de productos con base en Argentina, llamada Cooperativa Obrera Limitada. Este estudio, basado en el análisis de caso único, muestra que la veracidad de la información obtenida a partir de los datos representa la dimensión de Big Data con mayor efecto sobre los procesos decisorios de los entrevistados. Nos últimos anos, a incorporação de novas tecnologias por parte das empresas e o grande volume de dados gerados por elas têm motivado a incorporação de ferramentas que permitam análises desses dados para a coleta e utilização de informações que possam melhorar a gestão dessas organizações. Este novo cenário de grande quantidade de dados disponíveis, que potencialmente podem ser usados para melhorar a tomada de decisões nas empresas, é chamado de Big Data. Adaptar as empresas para esse novo cenário é fundamental para a criação de vantagens competitivas sobre seus concorrentes. Este artigo procura estabelecer o efeito dos “5V" (volume, variedade, velocidade, coragem e honestidade) de Big Data no processo de tomada de decisão de executivos de diferentes níveis hierárquicos, usando como cenário de estudo uma cooperativa de venda de produtos com base em Argentina chamada Cooperativa Obrera Limited. Este estudo, baseado na análise de caso único, mostra que a veracidade da informação obtida a partir dos dados representa a dimensão do Big Data com maior efeito nos processos de tomada de decisão.

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

This article provides insight into the effects of jitter induced noise in the pixel value when digital readout techniques are used for charge coupled devices (CCD). Available publications only focus in the CCD electronic noise component while this work analyzes the impact of jitter for readout schemes in which samples near and within the transition of the video signal between the pedestal level and charge level are used. This is the case when fast read outs are required or when optimal filtering techniques are used. The fast voltage swing of the video signal due to feed-through of the clocks in the aforementioned transition amplifies any timing error in the ADC sampling.

This article provides a design methodology to calculate an optimal filter for noise reduction in the readout of charge-coupled devices (CCDs) taking into account the charge transfer and feed-through due to capacitive coupling in the CCD. A detailed analysis of the dynamics in the video signal and charge transfer is presented. This includes the circuital modeling of the output stage of the CCD and the dynamics of the electronics in the video chain before the AD converter. The model is used to compute an optimal filter that minimizes the variance of the pixel noise and uses the samples of the charge transfer, before the charge is fully settled. This allows to shorten the pixel-time resulting in fastest readouts. The paper shows novel results of this processing in particular for Skipper CCD which uses a floating sense node to measure the charge packet.

In this paper the design of an optimal filter for noise reduction in the readout of a charge coupled device (CCD) with applications in particle detection is presented. The proposed approach uses measured data of the noise at the output amplifier of the CCD to obtain the coefficients of a filter that minimizes the pixel variance. The preliminary results show that this approach outperforms the standard dual slope integrator reading technique.

Fully depleted thick CCDs have been designed for infrared astronomy, but their low read-out noise of the order of a 2 e− and their considerable mass of a 5.2g, allows novel uses for them in low energy threshold particle detection applications, such as the CONNIE and DAMIC experiments. For both experiments, a reduction of the CCD read-out noise is will produce an increase in the detection efficiency. Few works have demonstrated that is possible reduce the noise applying digital processing techniques, and it is a field that must be explored. In this work the design of a CCD digital acquisition system will be presented. The impact of key parameters as quantization noise, front-end gain and ADC noise will be analyzed. A prototype of the front-end electronics was successfully tested with a CCD exposed to X-rays, achieving 2.3e− of readout noise.

Thick Charge Couple Devices have proven to be interesting particle detectors. The DAMIC and CONNIE collaborations are using this technology to search for the elastic scattering of a dark matter particle or a neutrino with a silicon nucleus, producing a nuclear recoil. The experiments reach unprecedented sensitivity at low energies (below 100 eV) by taking advantage of the low readout noise achieved by these devices. The present document describes an experimental setup at the Centra Atomico Bariloche, its noise treatment and its calibration.

Fully depleted thick CCDs have been designed for infrared astronomy, but their low read-out noise of the order of ≈2e− and their considerable mass of ≈5.2 gr, allows novel uses for them in low energy threshold particle detection applications, such as the CONNIE and DAMIC experiments. For both experiments, a reduction of the CCD read-out noise is vital. In this work we present a method to measure the read-out noise coming from electronic and non-electronic sources. The impact of the external electronics on the noise is discussed and its full characterization is presented.

In this article a stochastic model for point events expected in the output image of scientific CCDs is derived. This kind of events are typical in CCD systems dedicated to particle detection, such as DAMIC and CONNIE. The model includes the randomness of the charge movement in the silicon and the noise at the readout stage providing the base for an optimal detection technique.

In this article the feasibility of using charge coupled devices (CCD) to detect low-energy neutrinos through their coherent scattering with nuclei is analyzed. The detection of neutrinos through this standard model process has been elusive because of the small energy deposited in such interaction. Typical particle detectors have thresholds of a few keV, and most of the energy deposition expected from coherent scattering is well below this level. The CCD detectors discussed in this paper can operate at a threshold of approximately 30 eV, making them ideal for observing this signal. On a CCD array of 500 g located next to a power nuclear reactor the number of coherent scattering events expected is about 3000 events/year. Our results shows that a detection with a confidence level of 99% can be reached within 16 days of continuous operation; with the current 52 g detector prototype this time lapse extends to five months. Fil: Fernández Moroni, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Investigación En Ingeniería Eléctrica; Argentina. Universidad Nacional del Sur; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Estrada, Juan. Fermi National Accelerator Laboratory; Estados Unidos Fil: Paolini, Eduardo Emilio. Universidad Nacional del Sur; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina Fil: Cancelo, Gustavo Indalecio Eugenio. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Tiffemberg, Javier. Fermi National Accelerator Laboratory; Estados Unidos Fil: Molina, Jorge. Universidad Nacional de Asuncion; Paraguay

This article describes the design features and the first test measurements obtained during the installation of a novel high resolution 2D neutron detection technique. The technique proposed in this work consists of a boron layer (enriched in 10B) placed on a scientific Charge Coupled Device (CCD). After the nuclear reaction 10B(n,α)7Li, the CCD detects the emitted charge particles thus obtaining information on the neutron absorption position. The above-mentioned ionizing particles, with energies in the range 0.5-5.5MeV, produce a plasma effect in the CCD which is recorded as a circular spot. This characteristic circular shape, as well as the relationship observed between the spot diameter and the charge collected, is used for the event recognition, allowing the discrimination of undesirable gamma events. We present the first results recently obtained with this technique, which has the potential to perform neutron tomography investigations with a spatial resolution better than that previously achieved. Numerical simulations indicate that the spatial resolution of this technique will be about 15 μm, and the intrinsic detection efficiency for thermal neutrons will be about 3%. We compare the proposed technique with other neutron detection techniques and analyze its advantages and disadvantages. Fil: Blostein, Juan Jeronimo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Estrada, Juan. Fermi National Accelerator Laboratory; Estados Unidos Fil: Tartaglione, Aureliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Sofo Haro, Miguel Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Fernández Moroni, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Cancelo, Gustavo Indalecio Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Fermi National Accelerator Laboratory; Estados Unidos

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)

Scientific CCD detectors are typically readout using the Correlated Double Sampling (CDS) technique. At low pixel rates, noise of ~2e- RMS is typically achieved. The limitation for reaching lower noise comes from the 1/f component on the output of the CCD, and this noise cannot be eliminated using CDS. A new readout technique based on a digital filter is presented here for suppressing the 1/f. Using this new technique a noise of 0.4e- is achieved.

Scientific CCDs designed in thick high resistivity silicon (Si) are excellent detectors for astronomy, high energy and nuclear physics, and instrumentation. Many applications can benefit from CCDs ultra low noise readout systems. The present work shows how sub electron noise CCD images can be achieved using digital signal processing techniques. These techniques allow 0. 4 electrons of noise at readout bandwidths of up to 10 Kpixels per second while keeping the full CCD spatial resolution and signal dynamic range. © 2012 Springer Science+Business Media B.V. (outside the USA). Fil: Cancelo, Gustavo Indalecio Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Estrada, Juan Cruz. Fermi National Accelerator Laboratory; Estados Unidos Fil: Fernández Moroni, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina Fil: Treptow, Ken. Fermi National Accelerator Laboratory; Estados Unidos Fil: Zmuda, Ted. Fermi National Accelerator Laboratory; Estados Unidos Fil: Diehl, H. Thomas. Fermi National Accelerator Laboratory; Estados Unidos

The readout noise for Charge-Coupled Devices (CCDs) has been the main limitation when using these detectors for measuring small amplitude signals. A scientific CCD fabricated on a high-resistivity silicon substrate utilizing a floating gate amplifier with the capability of multiple sampling of the charge signal is described in this paper. The Skipper CCD architecture and its advantages for low noise applications are discussed. A technique for obtaining sub-electron readout noise levels is presented, and its noise and signal characteristics are derived. We demonstrate that with this procedure a very low readout noise of 0.2e − RMS can be achieved. The contribution of other noise sources (output stage, vertical and horizontal charge transfer inefficiency, and dark current noise) are also considered. The optimum number of samples for achieving the total lowest possible noise level is obtained. This technique is applied to an X-rays experiment using a 55Fe source. Fil: Fernández Moroni, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina. Fermi National Accelerator Laboratory; Estados Unidos Fil: Estrada, Juan. Fermi National Accelerator Laboratory; Estados Unidos Fil: Cancelo, Gustavo. Fermi National Accelerator Laboratory; Estados Unidos Fil: Paolini, Eduardo Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina Fil: Diehl, Thomas. Fermi National Accelerator Laboratory; Estados Unidos

Scientific grade CCDs show atractive capabilities for the detection of particles with small energy deposition in matter. Their very low threshold of approximately 40 eV and their good spatial reconstruction of the event are key properties for currently running experiments: CONNIE and DAMIC. Both experiments can benefit from any increase of the detection efficiency of nuclear recoils at low energy. In this work we present two different approaches to increase this efficiency by increasing the SNR of events. The first one is based on the reduction of the readout noise of the device, which is the main contribution of uncertainty to the signal measurement. New studies on the electronic noise from the integrated output amplifier and the readout electronics will be presented together with result of a new configuration showing a lower limit on the readout noise which can be implemented on the current setup of the CCD based experiments. A second approach to increase the SNR of events at low energy that will be presented is the studies of the spatial conformation of nuclear recoil events at different depth in the active volume by studies of new effects that differ from expected models based on not interacting diffusion model of electrons in the semiconductor.