Fast, low-noise x-ray image sensor technology for strategic x-ray astrophysics missions

High spatial- and spectral-resolution X-ray capabilities are essential for future strategic missions to address the key priorities set forth by the 2020 Decadal Survey on Astronomy and Astrophysics. These missions will require megapixel X-ray imaging detectors more capable than any available today, providing frame rates at least a factor of 20 faster and pixel aspect ratios twice as large, while retaining the low noise and excellent spectral performance of current sensors.

We summarize recent results from our NASA-funded technology development program to develop imaging sensors required for future strategic missions, and describe the prototype CCD sensor we are developing for AXIS, the Advanced X-ray Imaging Satellite mission concept recently proposed in response to NASA's Astrophysics Probe Explorer call. We have designed and are fabricating at MIT Lincoln Laboratory a 16-output, 1440 x 1440 pixel frame-store CCD to serve as a form/fit/function prototype for AXIS. This sensor incorporates the low-voltage, single-polysilicon gate and low-noise pJFET technologies we have proven in previous work. Our goal is to demonstrate a device meeting or exceeding the noise, spectral resolution and frame-rate requirements of AXIS when operated with the Multi-channel Readout Chip developed by our team at Stanford University. We also describe our strategy for optimizing CCD output amplifier architecture and design for even lower noise and faster readout for AXIS and subsequent high-energy astrophysics missions.