Two Proposed Experiments for the Detection of the Dirac Monopole

A magnetic monopole may be detected by its deflection in an electric field or by the character of the ionization it produces. The electric deflection experiment may be performed in a helium bubble chamber where helical (or spiral) tracks whose axes are parallel to the 0-lines would be certain evidence for the discovery of the monopole. Previous studies of the ionization have emphasized thnt the Bragg tail would be missing from a monopole track, as compared to a charged particle. This conclusion must be modified because of the thin-down of tracks of heavy nuclei. The tracks of heavy nuclei thicken and then thin down as they approach the end of their range. The tracks of monopoles are wedge-shaped, thinning down continuously as they approach the end of their range. Since the track width is due to knock-on electrons, or delta rays, any search for the monopole using this criterion must be conducted with electron-sensitive emulsions. (auth)