Design AndCold-Testing ofaHighGain, Ku-BandGyroklystron*

AttheUniversity ofMaryland, wehave beenevaluating theuseofgyroklystrons to drive RFaccelerators. Inorder touseour 500kV,500Asystem toenergize a17GHz accelerator structure built bytheHaimson Research Corporation [1], weneedalargesignal gain ofnearly 50dB.Toaccomplish this goal, wehavedesigned asix-cavity circuit inwhich thefirst three cavities operatenearthecyclotron frequency andthe last three cavities operate nearthesecond harmonic. Adequate efficiencies andgains arepredicted vianumerical simulations with theMAGYKL code[2], evenforaverageperpendicular toparallel velocity ratios (alphas) aslowasone.