Yu, J.B. Chen, J.X. He, H.Y. Kang, L. Liu, L. Liu, R.H. Nie, X.J. Ning, C.J. Wang, A.X. Wang, G.Y. Yu, Y.J. Zhang, J.S. Zhu, D.H. JACoW Publishing Geneva, Switzerland 2673-5520 978-3-95450-229-5 10.18429/JACoW-MEDSI2020-TUPA15 English 148-149 vacuum booster linac status gun Contribution to a conference proceedings 2021 2021-10 https://doi.org/10.18429/JACoW-MEDSI2020-TUPA15 https://jacow.org/medsi2020/papers/tupa15.pdf In order to protect the equipment such as BPM at low energy transport line (LB), a momentum collimator is designed with one movable absorber. This paper will show the mechanical design and manufacturing of the collimator.