1,272 research outputs found
Achieving sub-electron readout noise in Skipper CCDs
The readout noise for Charge-Coupled Devices (CCDs) has been the main
limitation when using these detectors for measuring small amplitude signals. A
readout system for a new scientific, low noise CCD is presented 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
a very low readout noise of RMS. Also, we show the results using the
detector in a low-energy X-ray detection experiment.Comment: 16 pages, 11 figure
The physics potential of a reactor neutrino experiment with Skipper CCDs: Measuring the weak mixing angle
We analyze in detail the physics potential of an experiment like the one
recently proposed by the vIOLETA collaboration: a kilogram-scale Skipper CCD
detector deployed 12 meters away from a commercial nuclear reactor core. This
experiment would be able to detect coherent elastic neutrino nucleus scattering
from reactor neutrinos, capitalizing on the exceptionally low ionization energy
threshold of Skipper CCDs. To estimate the physics reach, we elect the
measurement of the weak mixing angle as a case study. We choose a realistic
benchmark experimental setup and perform variations on this benchmark to
understand the role of quenching factor and its systematic
uncertainties,background rate and spectral shape, total exposure, and reactor
antineutrino flux uncertainty. We take full advantage of the reactor flux
measurement of the Daya Bay collaboration to perform a data driven analysis
which is, up to a certain extent, independent of the theoretical uncertainties
on the reactor antineutrino flux. We show that, under reasonable assumptions,
this experimental setup may provide a competitive measurement of the weak
mixing angle at few MeV scale with neutrino-nucleus scattering.Comment: 11 pages, 6 figure
Unraveling Fano noise and partial charge collection effect in X-ray spectra below 1 keV
Fano noise, readout noise, and the partial charge collection (PCC) effect
collectively contribute to the degradation of energy spectra in Charge Coupled
Devices (CCD) measurements, especially at low energies. In this work, the X-ray
produced by the fluorescence of fluorine (677 eV) and aluminum (1486 eV) were
recorded using a Skipper-CCD, which enabled the reading noise to be reduced to
0.2 e-. Based on an analytical description of photopeak shapes resulting from
the convolution of the PCC effect and Fano noise, we achieved a precise
characterization of the energy spectra. This description enabled us to
disentangle and quantify the contributions from both Fano noise and the PCC
effect. As a result, we determined the Fano factor and the electron-hole pair
creation energy. Additionally, we estimated the PCC-region of the sensor and,
for the first time, experimentally observed the expected skewness of photopeaks
at low energies.Comment: 8 pages, 5 figure
DAMIC at SNOLAB
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.Comment: 13 pages, 12 figures, proceedings prepared for 13th International
Conference on Topics in Astroparticle and Underground Physics (TAUP2013
Design of a Skipper CCD Focal Plane for the SOAR Integral Field Spectrograph
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 1k, 15 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 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 250m and backside processed with an antireflective coating. We
achieve a single-sample readout noise of for the best
performing amplifiers and sub-electron resolution (photon counting
capabilities) with readout noise 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
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