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 μm 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 ∼ 650μm thick, fully-depleted engineering-grade Skipper CCDs in preparation for performing similar characterization tests on science-grade Skipper CCDs which will be thinned to 250μm 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 subelectron resolution (photon counting capabilities) with readout noise σ ∼ 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.
Cerro Tololo Interamerican Observatory (CTIO) and the Southern Astrophysical Research Telescope (SOAR) are home to several telescopes, ranging from 4.2 to 0.9 meters in diameter. Every telescope has one or more working instruments, which are used every night of the year; keeping this vast amount of instruments (which includes a very big multi-ccd focal plane as well as visible and near infrared imagers and spectrographs) functioning in a way that ensures an appropriate science quality on each one of them is not a minor challenge. In order to help with this task we have developed an observatory-wide Detector and Instrument Quality Control system, which consist on a set of centralized tools: real time telemetry for all the instruments, automatic detector quality performance assessment, electronic logbooks, instrument software logging, image visualization, etc. All the data goes to databases and is available via web browsers.
KEYWORDS: Telescopes, Control systems, Sensors, Amplifiers, Field programmable gate arrays, Computer programming, Data acquisition, Observatories, Control systems design
The Southern Astrophysical Research (SOAR) Telescope is a 4.1 meter aperture telescope situated in Cerro Pachon, IV Region, Chile. The telescope works from the atmospheric cut-off in the blue (320 nm) to the near infrared and has been designed to deliver the highest possible angular resolution at optical wavelengths. The telescope has an altazimuth mount which is controlled by the Mount Control Unit (MCU) system.
The SOAR Mount Control Unit Upgrade Project seeks to replace the current MCU in the SOAR telescope. The new control unit will be based on the National Instruments cRIO-9039 controller, which will allow to improve the telemetry, improve fault detection and use new digital control techniques.
This will allow a more compact and robust MCU. This paper introduces the project, shows the control architecture and the current status of the new MCU implementation.
KEYWORDS: Sensors, Charge-coupled devices, Power supplies, Analog electronics, Signal detection, Control systems, Electronics, Clocks, Detector development, Calibration
The Torrent detector control system is being developed at NOAO as a follow-on to the MONSOON systems that
have been used successfully for instruments at several institutions. The poster will cover the evolution of
MONSOON into Torrent and will cover: Motivations, What's gained/What's lost, Major Technological Differences,
Goals, plans and first users.
KEYWORDS: Sensors, Control systems, Calibration, Field programmable gate arrays, Signal detection, Analog electronics, Mirrors, Clocks, Connectors, Power supplies
The MONSOON Torrent image Acquisition system is being designed partially to reduce the complexity in
configuring a Detector controller system. This paper will discuss how we have achieved this goal by creating a system
of automation for the configuration task. We also discuss how the automated systems work to insure proper focal plane
operation in the face of potential network, communications and controller hardware failures during observing sessions.
The Torrent hardware design is discussed in section 2. In Sections 4 and 5 we discuss the automated processes used
to develop the description of the Torrent hardware used by the rest of the automation system. In Sections 6 through 8 we
discuss the semi automated system configuration/integration/design software. In Section 9 we present the automated
run-time configuration tools and discuss how it operates in the face of various failures. In Section 10 we discuss how
Torrent and the automated systems will achieve the goal of reducing observing down time in the face of hardware
failures.
The MONSOON Detector Controller has successfully demonstrated the ability to control the complex image acquisition
and real time processing required to achieve quality science performance from the Orthogonal Transfer Array (OTA)
detector technology. A mosaic of four OTA detectors has been used to track multiple guide stars and apply charge shift
corrections to compensate for real time image motion. The control algorithms required to achieve this have been
embedded and distributed within the MONSOON controller to reduce the control loop latency and improve correction
efficiency. This paper highlights the flexibility of the MONSOON architecture in supporting the many roles required by
applications of scientific detectors.
The Dark Energy Survey Camera (DECam), when completed, is going to have one of the largest existing focal planes,
equipped with more than 70 CCDs. Due to the large number of CCDs and the tight space on the camera, the DECam
electronics group has developed new compact front-end electronics capable of flexibly and rapidly reading out all the
focal plane CCDs. The system is based on the existing MONSOON Image Acquisition System designed by the National
Optical Astronomy Observatory (NOAO), and it is currently being used for testing and characterization of CCDs. Boards
for the new readout are being developed in USA and Spain, with the first prototypes already produced and tested. The
next version with some improvements will be tested during 2008 and the system will be ready for production at the
beginning of 2009. Custom MONSOON boards and the electronics path will be described.
A description of the plans and infrastructure developed for CCD testing and characterization for the DES focal plane detectors is presented. Examples of the results obtained are shown and discussed in the context of the device requirements for the survey instrument.
The development of the Orthogonal Transfer Array CCD provides unique control mechanisms that allow a rich set of operating modes necessary to meet the demands of very wide-field imaging programs. The exclusive control modes of the OTA place strong requirements on the CCD controller to support the capabilities of the device while providing detector-limited performance. NOAO and WIYN Observatory have developed a controller based on the MONSOON Image Acquisition concept with the specific application for testing and characterizing the OTA performance and capability. The OTA controller implements control solutions for on-chip cell multiplexing, multiple read modes, high-speed guiding with multiple stars, predictive algorithms for temporal and spatial image motions, and application of electronic tip-tilt corrections. The MONSOON image acquisition system provides the flexibility needed to support the full capabilities of the OTA, while its extensibility can facilitate large mosaics of devices to meet the demands of future very large focal plane instruments.
The advent of large focal planes requiring many signal channels has exacerbated the problems associated with guaranteeing detector controller performance. The performance specifications for large focal plane controllers includes both 'per channel' requirements such as noise, linearity, dynamic range, etc. and 'system' requirements such as channel cross talk, gain matching, etc. To assess these performance parameters and fully characterize the controller before integration to a focal plane, the MONSOON team has adopted a testing methodology that is based on industry standard practices. This adoption has provided a consistent testing method that produces repeatable results and allows full characterization of the controller performance. This approach will provided a tool to assist in predicting focal plane performance before integration and establishes base line performance values for subsequent detector optimization efforts.
KEYWORDS: Sensors, Databases, Data conversion, Data acquisition, Software engineering, Imaging spectroscopy, Control systems, Associative arrays, Chemical elements, Java
MONSOON is the next generation OUV-IR controller project being developed at NOAO. The design is flexible, emphasizing code re-use, maintainability and scalability as key factors. The software needs to support widely divergent detector systems ranging from
multi-chip mosaics (for LSST, QUOTA, ODI and NEWFIRM) down to large single or multi-detector laboratory development systems. In order for this flexibility to be effective and safe, the software must be able to configure itself to the requirements of the attached detector system at startup. The basic building block of all MONSOON systems is the PAN-DHE pair which make up a single data acquisition node. In this paper we discuss the software solutions used in the automatic PAN configuration system.
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