In this work, we will present advancements in the design of Skipper-CCD sensors tailored for X-ray detection in environments with high optical background levels, such as those expected in space. These packages incorporate a custom-made aluminum shield placed on the CCD surface that successfully blocks over 99% of visible light while preserving the efficiency for keV X-rays. These features...
The Vera C. Rubin Observatory’s LSST Camera (LSSTCam) uses an instrument signature removal (ISR) algorithm to generate defect masks for its CCDs. We compare the defect mask generated by ISR to raw bias images from test runs 6 (22/06/2023) and 6b (16/11/2023), and verify the ISR defect algorithm performance. We find some differences in total number counts in the mask, with a detailed assessment...
The LSST Camera focal plane, the largest ever constructed, consists of 201 16-MegaPixel CCDs from two manufacturers. Viewed in room light the CCDs are blue colored, with one vendor’s sensors a consistent dark blue while the other ranges from light blue to very light greenish-blue. We interpret the visual appearance as due to the amount of light reflected, or 1 - QE, as a function of...
The Rubin Observatory LSST Camera exhibits novel crosstalk between charge-coupled device (CCD) amplifier segments that does not scale linearly with intensity. An open question regarding the characterization of this crosstalk is the fraction sourced in the camera readout electronics as compared with cabling and on-chip effects. Using a custom-made electronics board that simulates the load of a...
Rubin Observatory has a unique optical beam geometry. The large collecting area of the primary mirror, combined with atmospheric seeing-limited imaging across the large (9.6 $\rm deg^2$) field-of-view, enables the survey mission.
The combination drives a fast (F/1.2) beam geometry with unprecedented sensitivity to defocus driven, point spread function blur and shape transfer, even under...
The next generation of experiments for rare-event searches based on skipper Charge Coupled Devices (skipper-CCDs) will bring new challenges for the detector packaging and readout. Scaling the active mass and simultaneously reducing the experimental backgrounds in two orders of magnitude will require a novel high-density Silicon-based package, that must be massively produced and stored. In this...
The Vera C. Rubin Observatory, currently under construction in Cerro Pachón, Chile, will conduct the Legacy Survey of Space and Time (LSST) using the 3.2-gigapixel LSST Camera (LSSTCam) mounted on the 8.4-meter Simonyi Survey Telescope. The LSST aims to probe the nature of dark energy and dark matter, inventory the solar system, explore the transient optical sky, and study the evolution and...
We present first results of an on-telescope demonstration of a new technique to suppress bright atmospheric OH emission lines in near-infrared spectroscopic observations. On large ground-based telescopes, near-infrared spectroscopy is often limited by these lines, which can saturate on the order of minutes. Exposures longer than this will result in the loss of any useful information at these...
We measure the signal delay of CCD crosstalk using a test stand in preparation for the LSST Camera. We use a collimated beam projector to cast a narrow streak onto the CCD, mimicking a bright satellite track. We measure the strength and delay of the crosstalk signal simultaneously, using a linear (flux-independent) and a non-linear (flux-dependent) model, on individual exposures or on all...
The Veloce facility on the Anglo-Australian Telescope aims to implement precision radial velocity capabilities, for a fraction of the traditional cost. One aspect of the required cost saving is compressing an under sampled integral-field unit echelle spectral format onto three 4kx4k e2v CCDs. Analysing the data to obtain precision velocity measurements calibrated with a laser-frequency comb...
At Las Cumbres Observatory (LCOGTN) we have introduced CMOS-based imagers (QHY600 with Sony IMX455 sensors) as the main cameras in our global network of ten 35-cm telescopes. The uses are for our global education program (Global Sky Partners) and professional astronomy (e.g., TESS planet transit follow-up). The deployment of CMOS detectors in the small telescope network also serves as a...
The Nancy Grace Roman Space telescope, set to launch in 2026, will bring unprecedented precision to measurements of weak gravitational lensing. Because weak lensing (WL) is an inherently small signal, it is imperative to minimize systematic errors in measurements as completely as possible; this will ensure that the lensing measurements can be used to their full potential when extracting...
To be widely adopted as charge quantizing detectors, large format Skipper CCDs must be able to read out in minutes with low enough noise to quantize charge. Careful optimization of the time to reach charge quantization is needed to limit the number of parallel readouts required to values that will fit along the side of a CCD. In this work, we present a python tool developed to estimate the...
Existing Charge-Coupled Devices (CCDs) operate by detecting either the electrons or holes created in an ionization event. We propose a new type of imager, the Dual-Sided CCD, which collects and measures both charge carriers on opposite sides of the device via a novel dual-buried channel architecture. This dual detection strategy provides exceptional dark-count rejection and enhanced timing...
In this work, we studied the tree-rings in the LSST camera. Specifically, we compared the tree-rings observed in flat images under the normal operating voltage back bias and under a 0-volt back bias. We showed that tree-rings in the 0-volt back bias flat images have higher signal-to-noise ratios (SNR) and are more easily detectable, which therefore can be used to better infer tree-ring...
Wide Field Camera 3 (WFC3) is a fourth-generation imaging instrument installed on the Hubble Space Telescope during Servicing Mission 4 in 2009. WFC3 features two independent channels: the Ultraviolet-Visible channel (UVIS), sensitive to 200-1000 nm, with a pair of ~2K x 4K CCDs, and the Infrared channel (IR), sensitive to near-IR approximately 800-1700 nm, with a ~1K x 1K HgCdTe array. WFC3...
During the latest electro-optical testing runs of the LSST Camera, a long-range (>20 pixels) correlation was discovered in flat pair images that was not seen in previous testing runs. As we tried to determine the source, we noticed a turbulence pattern in difference images similar to that of atmospheric weather effects on-sky data. This pattern changes temporally and can be seen changing at...
