This SBIR Phase I project will deliver a breakthrough in particle-detection sensors, by integrating an amplifying junction as part of the detector topology. Focusing on energetic particle detection in the heliosphere, the resulting leap in the resolution with which the deposited charge is measured results in far more precise energy and position measurements, from which the certainty in the particle identification is increased. Silicon is chosen as the material upon which the avalanche particle detector (APaD) will be developed because it possesses high stopping power for ions, low material cost, and an extensive microelectronic fabrication base. We have previously made both: a) low-noise silicon detectors for ion and high-energy sensing, and b) avalanche photodiodes (APDs) for optical photon sensing. The objective of the project is to integrate the two topologies so that we can compare the energy resolution with and without on-chip amplification across the energy range 10 keV 3 MeV, with a goal of three times improvement in resolution at 80 keV.