Author:
Tarvainen O,Faircloth D,Lawrie S,Sarmento T,Abel R,Macgregor J,Cahill C,Stanley T,Whitehead M,Wood T
Abstract
Abstract
We have developed a model predicting the equilibrium caesium coverage work function of the cathode (in eV) and the expected H- beam current (in arb. units) of the ISIS Penning ion source. The model is based on semi-empirical expressions for the cathode work function, negative ion surface ionization yield, and caesium adsorption and desorption rates. We compare the model predictions to experimental data with 760 μs discharge and 250 μs beam pulses. It is concluded that the ISIS Penning ion source operates near the optimum cathode work function in a wide range of caesium pressures and cathode temperatures. The model implies that long pulse operation of the source requires elevated Cs oven temperature and improved cathode cooling.
Subject
General Physics and Astronomy
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献