The objective of this study is to demonstrate a sensitive Raman technique for sensing degradation of propellant
stabilizers like MNA and 2-NDPA that are commonly used in some missiles. The functionality of missiles and rockets
are often evaluated by being fired or decomposed at routine time-intervals after prolonged storage. However, these
destructive testing techniques for determining long-term rocket motor aging and shelf-life are extremely costly. If
successful, the Raman technique could be utilized to determine the health of propellant stabilizers without dismantling
the missiles as is commonly done at present. Raman technique is to measure concentrations of propellant stabilizers
between 0.1-2% in glycerin. Two different lasers at 785 nm and 532 nm are used for developing this technique. A
secondary objective is to develop a theoretical model that predicts temperature as a function of time and position inside
the cylindrical storage container of MNA or 2-NDPA stabilizer. This model can help in understanding the thermal
degradation of propellant stabilizers.
Raman measurements, using a 785nm laser, are taken of Ammonium Nitrate and Sodium Nitrate buried in sand. Nitrate is kept in clear plastic containers and buried underneath sand at various depths. Raman measurements are then taken at distances of 5m and 20m, with the sand being completely dry as well as completely wet. A different set of experiments was conducted with Nitrate buried in sand in a glass container, where no Raman signal was seen in dry sand. Water was then added at the edge of the container and allowed to migrate to the bottom. Raman measurements are then taken at a distance of 7mm over time to detect Nitrates brought to the surface by water as it wicks to the surface.