The disclosure describes various aspects of a shed-resistant thermal atom source. More specifically, a thermal atom source is described for uniform thermal flux of target atomic species in which a metal wadding material is used as an intermediary surface for sublimation of the atoms, preventing the source material from shedding or dropping. In an aspect, a thermal atom source may include a container with closed and open ends, and inside a source material near the closed end and a wadding between the source material and the open end; a heater coupled to the closed end; one or more clamps configured to secure the container and the heater; and a current source coupled to the container and the heater to cause a temperature to increase such that a portion of the source material is released and diffuses to the open end through the wadding prior to being emitted as a flux.