Wambacher's dissertation at the 2nd Physics Institute was supervised by Marietta Blau, with whom Wambacher continued to collaborate also after her Ph. D. graduation in 1932. The cooperation of the two women referred to the photographic method of detecting ionizing particles. For their methodical studies at the Institut für Radiumforschung of the Austrian Academy of Sciences in Vienna, Blau and Wambacher received the Lieben Prize of the Austrian Academy of Sciences in 1937. Also in 1937, Blau and Wambacher jointly discovered "disintegration stars" in photographic plates that had been exposed to cosmic radiation at an altitude of 2300 m above sea level. These stars are the patterns of particle tracks from nuclear reactions (spallation events) of cosmic-ray particles with nuclei of the photographic emulsion.
After Blau had to leave Austria in 1938, Hertha Wambacher continued working on the identification of particles from nuclear reactions of cosmic rays with the emulsion constituents. With this work, she obtained her university teaching certification in 1940. She taught classes at the University of Vienna. In 1945, Wambacher who – according to her own words – had belonged to the NSDAP since 1934, was removed from the University of Vienna. She was detained in Russia and is said to have returned only in 1946. She contracted cancer, but was still able to work in a research laboratory in Vienna.
Wambacher died from cancer on 25 April 1950.