Ionisation Efficiency in Conical Hot Cavities
M. Turek
Institute of Physics, Maria Curie Skłodowska University in Lublin, pl. M. Curie-Skłodowskiej 1, 20-031 Lublin, Poland
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Surface ionisation in a new type of hot cavity characterised by the shape of a truncated cone is considered in the paper. Influence of the hot cavity shape and its temperature on the ionisation efficiency of stable and long-lived nuclides is under investigation and the supremacy of elongated conical cavities is proven. The role of the extraction opening size is studied and its optimal diameter ( ≈ 1 mm) is found for the considered cavity shapes. It is shown that the extraction voltages of 1-2 kV are large enough to obtain high efficiencies and saturation of the current-voltage curves is observed above these values. Changes of ionisation effciency with the ioniser temperature are investigated - increase of ion yield with T is observed. It was proven that cold spots inside the ioniser cavity (near the extraction opening - in the considered case) can degrade ion source performance by several tens percent.

DOI: 10.12693/APhysPolA.132.259
PACS numbers: 07.77.Ka, 07.05.Tp, 34.35.+a