Nuclear Techniques ›› 2019, Vol. 42 ›› Issue (12): 120503-120600.doi: 10.11889/j.0253-3219.2019.hjs.42.120503


Design and simulation of vacuum system in energy selection section for HUST-PTF

Aote LIU Xu WANG Jian LIANG Zhikai LIU Kaifeng QIN Bin CHEN   

  1. Institute of Applied Electromagnetic Engineering, Huazhong University of Science & Technology, Wuhan 430074, China
  • Received:2019-08-14 Revised:2019-10-08 Online:2019-12-10 Published:2019-12-18
  • Supported by:
    the National Key Research and Development Program of China(2016YFC0105305);National Natural Science Foundation of China(11975107);Program for HUST Academic Frontier Youth Team

Abstract: Background

Energy selection section (ESS) is an important part of the beam line of Huazhong University of Science and Technology Proton Therapy Facility (HUST-PTF). It is located downstream of the cyclotron and includes a set of quadrupoles, a kicker magnet system, an energy degrader system and a double bending achromatic (DBA) section. Various types of vacuum pipe and several inserts are placed in this section. What’s worse, large radiation exists in the downstream of the degrader.


This study aims at the design of the vacuum system and the selection of the vacuum pump to satisfy system requirements for better than 5×10-4 Pa dynamic vacuum pressure.


First of all, the ESS vacuum system was simulated by Monte Carlo method in the MOLFLOW software. Then the pressure distributions under different working conditions were analyzed, and the mechanical strength of various vacuum pipe was calculated and checked.


The simulation results show that the pressure in the ESS is lower than 4.14×10-5 Pa, an order of magnitude better than the system requirement. The mechanical deformation of various vacuum pipes is less than 0.3 mm, avoiding the extra beam loss.


Both of the dynamic vacuum pressure and the mechanical strength can meet the design requirements.

Key words: Vacuum system, Energy selection section, Vacuum chamber, MOLFLOW, Beam line

CLC Number: 

  • TB753