What particles do Negative Ion Cyclotrons accelerate?

Negative ion cyclotrons are designed to accelerate negatively charged ions, which in the case of the question refers specifically to hydrogen atoms in the form of negative hydrogen ions (H⁻). These ions consist of one proton and two electrons. The structure of the cyclotron allows these negative ions to gain energy as they spiral outward in the magnetic field, resulting in higher velocities.

Negatively charged hydrogen ions are particularly useful in certain applications, such as in nuclear physics and medical treatments, including proton therapy for cancer where, after being accelerated, the negative ion can be stripped of one electron, resulting in an accelerated proton. This functionality makes the negative ion cyclotron an important tool in both research and clinical applications.

While other particles such as neutrons, electrons, and protons can be accelerated; they do not apply to the operation of a negative ion cyclotron. Specifically, neutrons are neutral and cannot be accelerated by electric fields, electrons are typically accelerated in electron cyclotrons rather than negative ion cyclotrons, and protons, while they are the end product of the acceleration process, are not the particles that the negative ion cyclotron initially accelerates.