I am going to create a simple high school exercise where the students schould calculate the energy from a particle track in a magnetic field. To make the exercise more authentic I am looking for a (maybe historic) high quality image of a cloud chamber of $\alpha$, $\beta^+$ or $\beta^{-}$ particle tracks from a published paper together with a scale and the magnitude of the magnetic field. Since the exercise should be in the context of nuclear physics, the source should be a radioactive decay (not a pair production or...). Different decay examples would be welcome.
I didn't find anything searching the web. However I guess someone knowing the (historic) original papers in this field knows where to look for it. So I am asking for a reference for this.