Nuclear Science and Techniques ›› 2017, Vol. 28 ›› Issue (4):
• NUCLEAR CHEMISTRY,RADIOCHEMISTRY,RADIOPHARMACEUTICALS AND NUCLEAR MEDICINE •
Jie Wang, Bo Zhang, Yan-Hui Xu, Yong Wang
Supported by the National Natural Science Funds of China (No. 11205155) and Fundamental Research Funds for the Central Universities (WK2310000041).
An accelerator storage ring needs clean ultrahigh vacuum. A TiZrV non-evaporable getter (NEG) film deposited on interior walls of the chamber can realize distributed pumping, effective vacuum improvement and reduced longitudinal pressure gradient. But accumulation of pollutants such as N2 and O2 will decrease the adsorption
ability of the NEG, leading to a reduction of NEG lifetime. Therefore, an NEG thin film coated with a layer of Pd, which has high diffusion rate and absorption ability for
H2, can extend the service life of NEG and improve the pumping rate of H2 as well. In this paper, with argon as discharge gas, a magnetron sputtering method is adopted to
prepare TiZrV-Pd films in a long straight pipe. By SEM measurement, deposition rates of TiZrV-Pd films are analyzed under different deposition parameters, such as magnetic field strength, gas flow rate, discharge current, discharge voltage and working pressure. By comparing the experimental results with the simulation results based on Sigmund’s theory, the Pd deposition rate C can be estimated by the sputtered depth.
Magnetron sputtering method,
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