arXiv subjects

Haley Stueber

Publications and source records attributed to Haley Stueber.

3 recordsLinked to original sources

arXiv2026

Advancing X-Ray Camera Front-End Electronics Architecture through the AXIS-TAP Technology Platform

Advancing time-domain soft X-ray astronomy demands focal plane readout electronics capable of high-speed digitization with low noise while maintaining spectral fidelity across multiple detector channels. The Advanced X-ray Imaging Satellite (AXIS), a NASA Probe-class mission concept, provided the driving requirements and heritage for developing a generalized high-speed (>=5 fps) camera Front-End Electronics (FEE) architecture applicable to future soft X-ray missions. The FEE architecture defines a modular, dual-box redundant configuration to operate a focal plane of four 16-channel CCDs, with functional partitioning for power distribution, thermal management, mechanism control, and image data acquisition and transmission to the spacecraft. To validate the core signal chain architecture, particularly the analog-to-digital conversion, FPGA-based processing, and Ethernet data transmission, a dedicated technology demonstrator, AXIS-TAP (ADC Testing and Acquisition Platform), has been designed and is currently in fabrication. AXIS-TAP employs commercial equivalents of radiation-tolerant components (FPGA, ADCs, Ethernet PHY) and interfaces directly with the STA Archon benchtop readout system, enabling simultaneous image acquisition from both systems to validate that the flight-like architecture achieves equivalent or superior noise performance. This paper presents the FEE architectural framework, the AXIS-TAP demonstrator design, and the design principles that enable scalability to future soft X-ray missions with similar detector requirements. Performance validation results will be reported upon completion of AXIS-TAP system integration and testing.

astro-ph.IM↗

arXiv2024

X-ray speed reading with the MCRC: prototype success and next generation upgrades

The Advanced X-ray Imaging Satellite (AXIS) is a NASA probe class mission concept designed to deliver arcsecond resolution with an effective area ten times that of Chandra (at launch). The AXIS focal plane features an MIT Lincoln Laboratory (MIT-LL) X-ray charge-coupled device (CCD) detector working in conjunction with an application specific integrated circuit (ASIC), denoted the Multi-Channel Readout Chip (MCRC). While this readout ASIC targets the AXIS mission, it is applicable to a range of potential X-ray missions with comparable readout requirements. Designed by the X-ray astronomy and Observational Cosmology (XOC) group at Stanford University, the MCRC ASIC prototype (MCRC-V1.0) uses a 350 nm technology node and provides 8 channels of high speed, low noise, low power consumption readout electronics. Each channel implements a current source to bias the detector output driver, a preamplifier to provide gain, and an output buffer to interface directly to an analog-to-digital (ADC) converter. The MCRC-V1 ASIC exhibits comparable performance to our best discrete electronics implementations, but with ten times less power consumption and a fraction of the footprint area. In a total ionizing dose (TID) test, the chip demonstrated a radiation hardness equal or greater to 25 krad, confirming the suitability of the process technology and layout techniques used in its design. The next iteration of the ASIC (MCRC-V2) will expand the channel count and extend the interfaces to external circuits, advancing its readiness as a readout-on-a-chip solution for next generation X-ray CCD-like detectors. This paper summarizes our most recent characterization efforts, including the TID radiation campaign and results from the first operation of the MCRC ASIC in combination with a representative MIT-LL CCD.

astro-ph.IM↗

arXiv2023

The high-speed X-ray camera on AXIS

AXIS is a Probe-class mission concept that will provide high-throughput, high-spatial-resolution X-ray spectral imaging, enabling transformative studies of high-energy astrophysical phenomena. To take advantage of the advanced optics and avoid photon pile-up, the AXIS focal plane requires detectors with readout rates at least 20 times faster than previous soft X-ray imaging spectrometers flying aboard missions such as Chandra and Suzaku, while retaining the low noise, excellent spectral performance, and low power requirements of those instruments. We present the design of the AXIS high-speed X-ray camera, which baselines large-format MIT Lincoln Laboratory CCDs employing low-noise pJFET output amplifiers and a single-layer polysilicon gate structure that allows fast, low-power clocking. These detectors are combined with an integrated high-speed, low-noise ASIC readout chip from Stanford University that provides better performance than conventional discrete solutions at a fraction of their power consumption and footprint. Our complementary front-end electronics concept employs state of the art digital video waveform capture and advanced signal processing to deliver low noise at high speed. We review the current performance of this technology, highlighting recent improvements on prototype devices that achieve excellent noise characteristics at the required readout rate. We present measurements of the CCD spectral response across the AXIS energy band, augmenting lab measurements with detector simulations that help us understand sources of charge loss and evaluate the quality of the CCD backside passivation technique. We show that our technology is on a path that will meet our requirements and enable AXIS to achieve world-class science.

astro-ph.IM↗