Energy harvesting system for deployment of Wireless Sensor Networks in Nuclear Fusion Reactor

In the recent times, as applications of Wireless Sensor Network (WSN) are growing, attention is being paid to running WSN on alternate sources of energy enabling longevity of sensor node. opticalCENSE is one such application of sensor network to measure the parameters inside a Tokamak (a type of a Nuclear Fusion Reactor), where we are investigating the use of optical link for communication. Tokamak is a device used to magnetically confine the plasma at high temperatures. Once the node is placed inside reactor, it is very difficult to take it out. In such harsh conditions, battery operated sensor nodes cannot be used, so we are investigating the use of radio frequencies (RF) present inside the Tokamak to recharge the battery or other energy storage device. Thus a system for harvesting radio frequencies is proposed and being developed using state of art harvesting and storage technologies. The prototype is designed and tested for efficiency using two energy buffers, Supercapacitor and Thin Film batteries. This paper discusses the aspects of energy harvesting with respect to opticalCENSE which pertains to using RF as energy source, energy buffer technology and design constraints while designing such sensor nodes. RF source at a particular frequency was used to test the system to charge the energy buffers efficiently.