Monitoring and building our understanding of space weather is necessary to protect current and future astronauts and hardware, as well as further our understanding of its effects on atmospheric development and loss. This project has developed two radiation-hardened sensor frontends to measure the ion composition of the solar wind aboard the Solar Probe ANalyzer for Ions (SPAN-Ion). SPAN-Ion uses time-of-flight mass spectrometry to distinguish ions by their mass: charge ratios; the target architecture for future missions decreases mass and increases speed in exchange for several orders of magnitude reduction in sensor response. A modified constant fraction discriminator provides time-of-arrival measurements independent of pulse amplitude and power spectral density. The frontend was designed using the Berkeley Analog Generator to enable agile design iteration, cross-applicability to other target specifications, and semi-automated verification against radiation single event effects and total ionizing dose. Two chips have been fabricated. The first chip was fabricated in 0.18um bulk CMOS with 3 mA of current drawn from an internally regulated 1.8 V supply, and a measured timing walk of 601 ps over a 10x change in input pulse amplitude with a worst-case jitter of 743 ps. The second chip is now being tested.
Project currently funded by: Other