Yes, a magnetic field is produced around a thin beam of moving alpha particles, but not around a beam of moving neutrons. Alpha particles, being positively charged, constitute a current in the direction of their motion, generating a magnetic field. Neutrons, being electrically neutral, do not carry an electric current and therefore do not produce a magnetic field.
Explanation:
Alpha Particles:
Alpha particles, which are helium nuclei (two protons and two neutrons), are positively charged. When a beam of alpha particles moves, it effectively carries a current in the direction of their motion. This current, just like the current in a wire, generates a magnetic field around the beam.
Neutrons:
Neutrons are electrically neutral particles. Unlike charged particles, neutrons do not experience forces due to electric fields. Since neutrons do not constitute a current, they do not produce a magnetic field.