Enhanced Beta-Batteries: A Long Life Power Source for Sensors Monitoring WMD

While many applications may have access to harvestable energy in the form of solar radiation (or other ambient light), wind, environmental vibration, or wave motion, not all do. In this proposal, RMD targets the most challenging applications, sensors that must operate for many months or years and which have undependable or no access to environmental energy. These sensors need a self contained, compact energy source that contains, at the outset, all the energy required for the length of the mission. We propose to provide this energy through the development of a novel beta battery, to convert the energy of long-lived beta emitters such as strontium 90 (29 years) into usable electrical power. Beta batteries have been known for fifty years, but have suffered from two shortcomings. First, radiation damage to the semiconductor junction used for the conversion limits either the lifetime of the device or the maximum allowable particle energy of the incident radiation. Second, absorption in the radioactive source limits the efficiency of the device. RMD proposes an innovative energy conversion method that resolves both of these issues and allows the development of higher power, higher efficiency beta batteries than were possible in the past.