Statement of the problem or situation that is being addressed in your application. High-priority future HEP experiments include neutrino experiments including those sited deep underground, next generation direct searches for dark matter, and astrophysical surveys to understand dark energy, including cosmic microwave background (CMB) experiments. Many HEP experiments are operated in the deep cryogenic regime (10-100 mK) with large numbers of readout channels required. Data acquisition and controls signals from the mK stage out to room temperature require high-fidelity RF signals, extremely low noise, and low thermal load on the cryogenic systems General statement of how this problem is being addressed. Alphacore will develop data conversion circuits, including analog-to-digital converters (ADCs) and digital-to-analog converters (DACs), that will bring ultra-low power, low noise, and better performance than the current state-of-the-art to applications with deep cryogenic operating conditions. The main target application for these data converters are high energy physics (HEP) experiments operated in cryogenic temperatures of 4K and below that require large numbers of readout channels. What is to be done in Phase I? The specific technical objectives for the Phase I research and development are: 1) Low-temperature (cryogenic, down to 4 K) characterization of 22nm FDSOI techncology (including digital and analog sub-circuits), 2) Innovative preamplifier design calibrated for wide-temperature operation (using low T data from the objective 1), 3) >100MS/s 14-bit ADC design (using low T data), 4) >100MS/s 14-bit DAC design (using low T data). Commercial Applications and Other Benefits (limited to the space provided). Applications for our cryogenic data converters range from future CMB experiments that will have large focal plane arrays with ~500,000 superconducting detector elements, to axion dark matter searches with similar channel counts to reach to high axion masses, to large-scale phonon-based WIMP (weakly interacting massive particle) dark matter searches. Missions such as communications, remote sensing and weather monitoring can benefit from subsystems using cryogenic technology, including high speed/low power analog to digital converters. Alphacores proposed low-power, cryogenic ADCs can be also be used to achieve higher sensitivity in the readout of large arrays of cryogenic photon detectors, used to provide visibility through degraded visual environments such as dense fog.
