Development of integrated readout electronics for next generation X-ray CCDs

The Physics of the Cosmos Program Annual Technology Report of 2017 lists "Fast, low-noise, megapixel X-ray imaging arrays with moderate spectral resolution" as one of the fields with the highest priority for technology maturation. The Lynx large mission concept now under study by NASA for presentation to the 2020 Decadal Survey in Astronomy and Astrophysics includes a notional high-definition X-ray imaging instrument (HDXI). This instrument requires a combination of readout rate, noise, spatial resolution and size that cannot be met by currently-mature technologies. One of the most significant challenges is the targeted 300 fold increase in frame rate compared to Chandra, with constrained power and mass budgets. This technological challenge is being addressed from two sides: improvement of the CCD technology and its output stages; and segmentation of the CCD readout architecture with an associated increase in output nodes. Both approaches require concurrent development of the readout electronics to utilize the novel CCD output stages, to provide the (substantial) increase in channel density to match the CCD segmentation, and to mature the required interconnect and integration technology. Building on our experience with Athena and LSST, and utilizing circuit concepts that have been successfully used for both pn-CCDs (JFET outputs) and DEPFETs (buried gate PMOS pixels), we propose to design, manufacture and test a prototype readout ASIC suitable for future X-ray missions. This will be integrated and tested with a high-speed Lynx prototype CCD detector currently in development at MIT-Lincoln Labs. We anticipate that our 16-channel prototype ASIC will be capable of reading the MIT-LL CCDs at an output rate of 5Mpix/sec and with a noise performance as low as 3.2 electrons, in line with the requirements for the notional Lynx HDXI. Our test setup will leverage existing X-ray detector facilities at MIT, including a commercial data acquisition system, allowing us to study different CCD outputs and their behaviors, various signal filtering options and specific implementations in an efficient and goal-oriented manner. A key aspect of our study is to investigate the feasibility of using massively parallel Analog-to-Digital Converters and digital shaping techniques for signal filtering. In principle, this offers the potential for substantial gains, providing exquisite control in studies of noise, settling times, clock coupling, amplifier response and crosstalk, allowing us to tune for optimum performance with short turnaround times. In parallel, we will also investigate a more traditional state-of-the-art analog filter approach incorporating dual slope integrators, with the potential addition of zero-suppressed readout to reduce the required analog multiplexing bandwidth. Our study would represent NASA's first comprehensive investigation of architectures and requirements for optimized readout electronics for future large-format X-ray imaging detectors. We will deliver a deeper understanding of the merits and challenges of alternative approaches, and recommend a path toward a scalable readout electronics solution for future missions with high-performance, megapixel X-ray imaging sensors.

The Astrophysics Research and Analysis program (APRA) supports suborbital and suborbital-class investigations, development of detectors and supporting technology, laboratory astrophysics, and limited ground based observing. Basic research proposals in these areas are solicited for investigations that are relevant to NASA's programs in astronomy and astrophysics, including the entire range of photons, gravitational waves, and particle astrophysics. The emphasis of this solicitation is on technologies and investigations that advance NASA astrophysics missions and goals.

This is early/mid-stage (TRL 2) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.