Brief welcome to open session 1
Astro2020 Decadal Survey study for Astrophysics articulated a number of exciting science ranging from exoplanet characterization to general astrophysics including galactic and stellar science that require high-efficiency, high throughput instrumentation ranging from ultraviolet through visible and near infrared. A major contributing factor to the throughput is determined by the efficiency and...
The near-infrared spectrometer and photometer (NISP) focal plane, comprising 16 H2RGs and Sidecar ASICs, was successfully commissioned in the second half of 2023. Flight models of the detectors have been extensively tested on the ground during the C/D phase by NASA and the Euclid consortium, offering a good point of comparison with flight commissioning data.
The proposed presentation aims to...
Non-destructive readout capability of the Skipper Charge Coupled Device (CCD) has been proven to be a powerful technique to reduce the noise limitation of conventional silicon devices even to levels that allow single-photon or single-electron counting. The noise reduction is achieved by spending extra time taking several measurements of the same pixel charge. This extra time has been a...
Single electron Sensitive Read Out (SiSeRO) is a novel on-chip charge detector output stage for silicon charge-coupled device (CCD) image sensors that can enable significantly greater responsivity and improved noise performance than traditional CCDs. Developed in collaboration with MIT Lincoln Laboratory and fabricated in their CCD process technology, SiSeRO devices use a p-MOSFET transistor...
Optical detectors in future astronomical facilities require both single-electron resolution and fast readout capability to meet ambitious science goals including obtaining spectra for diffuse dwarf galaxies, identifying rapidly fading transient events, and directly imaging Earth-like extrasolar planets. Skipper CCDs used in dark matter detection experiments have shown their ability to reach...
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...
Teledyne produces high performance visible focal plane arrays (FPAs) at e2v Space Imaging (United Kingdom) and DALSA (Canada). Infrared FPAs are produced at Teledyne Imaging Sensors in Camarillo, California.
This presentation will review the different types of visible and infrared FPAs and discuss the backside illuminated CMOS and CCD visible FPAs and hybrid CMOS IR FPAs offered by...
STA specializes in the development of custom CCDs, controllers, and imaging systems for a wide variety of applications. We discuss recent sensor fabrication and testing efforts, including performance results from a prototype skipper CCD and derived skipper designs in fabrication now.
At MIT’s Kavli Institute for Astrophysics and Space Research, exciting instrumentation/characterization work is being conducted across multiple research groups to push the technology of imaging detectors for astronomy applications. This overview presentation will highlight the recent progress/testing of several detectors across multiple wavelengths.
- IR/SWIR: The Wide-Field Infrared...
The SPHEREx satellite will survey the full sky between 0.75 - 5.0 micron in over 100 wavelengths to study cosmic inflation, galaxy formation, and bionic ice distribution in the Milky Way. The focal plane assemblies consist of six HAWAII-2RG (H2RG) detectors equipped with linear variable filters (LVF) to vary the spectral response along one spatial direction with resolving power R = 35 to 130....
Thick, fully depleted charge-coupled devices (CCDs) are known to exhibit non-linear behavior at high signal levels due to the dynamic behavior of charges collecting in the potential wells of pixels, called the brighter-fatter effect (BFE). This particularly impacts bright calibration stars, which appear larger than their intrinsic shape, creating a flux-dependent point-spread function (PSF)...
The brighter-fatter effect is an important systematic arising in CCD sensors, and its characterisation and mitigation have become quite routine in recent years, generally by means either of measuring the correlations in flat fields, or by directly measuring the signal dependent width of the point spread function in projected spots.
In this contribution we describe an investigation into...
In the pursuit of observing fainter astronomical sources and phenomena, a significant challenge in detector development lies in ensuring these devices can detect each individual photon they receive.
By amplifying each incoming photon by several orders of magnitude, Electron-Multiplying CCDs (EMCCDs), offer a promising solution to meet this challenge.
While these powerful detectors boast...
Photon counting detectors with Microchannel Plates (MCPs) provide unique capabilities in astronomy applications where detection of photons with very low dark count rate, large dynamic range, high spatial and timing resolution is required. Over the years development of this type of sensor has substantially improved giving enhanced counting rate capabilities, lifetime, spatial and temporal...
MOONS is a multi-object spectrograph that will be installed at the Nasmyth focus of the VLT ESO Telescopes in Chile. The instrument has approximately 1000 fibers over a field of view of 500 square arcminutes, with wavelength coverage from 0.6 to 1.8 um using CCDs and NIR detectors. Four of the six f/0.95 Schmidt cameras are dedicated to the NIR wavebands and are fitted with H4RG-15 detectors....
Image persistence in HAWAII-2RG HgCdTe detectors has been observed by multiple parties. Also known as latent signal, this effect occurs when sensor images following an illumination show a decayed form of the illuminated image even though the source has been removed and the detector has been reset. Using data from an engineering grade detector delivered for SPHEREx testing illuminated with a...
I will present preliminary results from the SuperBIT balloon-borne experiment - a 0.5 meter near-ultraviolet to near-infrared telescope with a Sony IMX 455 CMOS sensor designed to perform diffraction-limited imaging from the stratosphere. SuperBIT observed 30 galaxy clusters during its 45-night flight on a NASA superpressure balloon in the spring of 2023. I will discuss sensor...
The e2v and ITL CCDs used in Rubin Observatory's LSST-CAM are tested under realistic LSST f/1.2 optical beam in a lab setup. In the past this facility has been used to characterize these CCDs, exploring the systematic errors due to charge transport. Now this facility is being used to optimize the clocking scheme and voltages. The effect of different sequencers on the on-chip systematics such...
The Vera C. Rubin Observatory will perform the 10-year Legacy Survey of Space and Time using the 3.2-gigapixel LSST Camera that consists of 189 science CCDs. Each of the back-illuminated deep depletion 16-megapixel CCDs consists of 16 segments corresponding to independent video channels that are readout in parallel. Using the LSST Beam Simulator at UC Davis, we characterized the...
The focal plane of the LSST Camera for the Vera C. Rubin Observatory consists of 189 science CCD sensors and sensors for guiding (8) and wavefront sensing (4). The science sensors are deep-depletion and back-illuminated 4k x 4k CCDs with segmentation of 16 channels, manufactured by both Imaging Technology Laboratory (ITL; ITL STA3800) and Teledyne E2V (E2V CCD250). Three CCDs are grouped and...
The Nancy Grace Roman Space Telescope will study the dark matter content of the universe, the expansion history of the universe, and the diversity of exoplanets in the Galaxy using unprecedented wide field infrared surveys. Roman will accomplish this using a focal plane of 18 newly developed HgCdTe detectors. Roman’s detectors, the H4RG-10, are 4K x 4K format 10 micron pixel pitch devices...
HAWAII-4RG (H4RG) detectors will provide a substantial portion of the scientific output for both the Nancy Grace Roman Space Telescope (Roman) and the Prime Focus Spectrograph (PFS) on the Subaru Telescope. In the first half of this talk, I will present my work from the last few years on modeling detector-level effects present in Roman's flight candidates. Specifically, I focus on how these...
Ultra-low readout noise detectors will enable increased sensitivity to high-density and high-redshift spectroscopic surveys to place tighter constraints on dark energy and dark matter (e.g., a Stage-5 Spectroscopic Survey). We present advances towardplans for demonstrating the performance of an ultra-low noise Skipper CCD focal plane prototype for the SOAR Integral Field Spectrograph (SIFS)...
The 2020 Decadal Survey of Astronomy and Astrophysics (Astro2020) recommended technology development for a large, 6-m class, infrared/optical/ultraviolet space telescope as its highest priority for strategic space missions. The search for evidence of life on other worlds using spectroscopic biosignatures is a key science aim. Many important biosignatures; including H$_2$O and O$_2$, are strong...
Skipper-CCDs with sub-electron noise have been a transformative device for rare event searches. There is growing interest in using skipper-CCDs in future space-based telescopes, but skipper-CCDs need further development to realize their potential for space-based imaging. The DarkNESS mission will deploy an array of skipper-CCDs on a 6U CubeSat in Low Earth Orbit to search for electron recoils...
