Abstract: Mechanisms involved in cyrogenic flame stabilization are important in liquid rocker propulsion applications. These mechanisms are studied experimentally in this article by considering a single jet-flame formed by a coaxial injector fed by liquid oxygen (LOX) and gaseous hydrogen (GH(2)). The flame is analyzed by imaging the light emitted by hydroxyl (OH) radicals. To characterize the reaction zone structure one takes the average of the light emission signal. The result of this operation is then treated by numerical tomography (based on rite Abel transform) to get the local volumetric light intensity distribution. This method is used to study the effect of the LOX tube recess on the structure of the flame in the vicinity of the injection plane. It is shown that the recess augments the flame expansion angle and the size of the volume where the reaction takes place. (C) Academie des Sciences/Elsevier, Paris.