关键词: 强流重离子加速器装置, 钛合金内衬薄壁腔体, 3D打印, 结构优化, 真空特性

Abstract: The dipole magnet vacuum pipeline was critical equipment for the booster ring of HIAF. In order to attenuate the eddy current effect, reduce the gap of magnet, and decrease the difficulty of vacuum pipeline machining, the 3D-printed titanium alloy-lined ring wrapped in stainless steel with a thickness of 0.3 mm was created for fabricating a thin-wall chamber. The structural optimization of the titanium alloy-lined ring was carried out through simulation, and thin-wall chambers were fabricated for deformation testing and high-temperature baking testing. Evaluation of the outgassing performance of 3D-printed titanium alloy was completed. Ultimate vacuum tests were conducted before and after coating thin-wall chamber with Ti-Zr-V films, and a study of the effect of eddy current on vacuum performance was carried out. The results show that the stresses of stainless steel and titanium alloy are below the strength limit when the thickness of the titanium alloy-lined ring is as 4 mm, the width is as 11 mm and the spacing is as 15 mm. The deformation of the ring, with an arch height of 0.5 mm, is measured to be 0.78 mm, and the structure remained stable after 35 rounds of high-temperature baking at 250 ℃. The outgassing performance of TC4 titanium alloy and the ultimate vacuum performance of the thin-wall chamber meet the design criteria.

Key words: high intensity heavy-ion accelerator facility（HIAF）, titanium alloy-lined thin-wall chamber, 3D-printing, structure optimization, vacuum performance