Plasma diagnosis in a miniature penning ion source by a mass-energy analyer

Penning-type ion source performance for neutron generator applications is characterized partly by the atomic ion fraction. A miniature Penning ion source has been fabricated to investigate the atomic ion fraction of the deuterium plasma by a mass-energy analyer. The energy for the mass settings of 2 and 4, corresponding to D
⁺
and D
₂
⁺
ions respectively, show Guass distributions. The results show that the atomic ion fraction could vary from 2.26% to 5.63% by changing the pressure, the anode voltage and the discharge current. The results can provide useful information for the choosing of the discharge conditions.