PHOTOELECTRON YIELD OF SILICATE AND GRAPHITE GRAINS

The photoelectric yields of small silicate and graphite grains are cal culated as a function of incident photon wavelength for the purpose of modeling interstellar grains. The large surface-to-volume ratio of a small grain is expected to result in an increased photoelectric yield when compared with a bulk sample of the same material. The ratio of gr ain yield to bulk yield is calculated from the Mie solution for the fi elds inside a spherical particle and from assumptions regarding the el ectron emission process, yields are calculated from published bulk yie lds for wavelengths of 900-1500 Angstrom. for grain radii of 100 and 1 000 Angstrom. These results should be useful for future investigations of photoelectric emission from interstellar grains.