Non-Dispersive Atomic Absorption System for Engine Health Monitoring

We propose to design, construct and test a first implementation of a non-dispersive technique for the measurement of atomic absorption in the plumes of liquid rocket engines in altitude test facilities. Led by NASA Stennis Space Center (SSC), the observation of metal atom emission from liquid rocket engine exhausts at sea level conditions has become a highly successful health monitoring technique, but in altitude tests emission intensities are low. SSC developed an atomic absorption system which has provided useful measurements, but improved sensitivity is required. Non-dispersive atomic absorption presents a far simpler, smaller, lower cost alternative to other techniques with comparable spectral resolution and, of particular importance, should allow a more forgiving receiver geometry, so that noise-modulated source light or plume emission can be eliminated.