Nuclear Techniques ›› 2019, Vol. 42 ›› Issue (5): 50201-050201.doi: 10.11889/j.0253-3219.2019.hjs.42.050201


The development of Quadrupole-D magnet for CSNS drift tube

Bo LI1,2,Huachang LIU1,2,Keyun GONG2,Qiang CHEN1,2,Yun WANG1,2,Xiaolei WU1,2,Ahong LI1,2   

  1. 1. Dongguan Institute of Neutron Science, Dongguan 523808, China
    2. China Spallation Neutron Source, Institute of High Energy Physics, Chinese Academy of Sciences, Dongguan 523803, China
  • Received:2019-03-04 Revised:2019-04-09 Online:2019-05-10 Published:2019-05-16
  • About author:LI Bo, male, born in 1986, graduated from University of Science and Technology of China in 2012, master student, focusing on new structure of proton linac|LI Bo, male, born in 1986, graduated from University of Science and Technology of China in 2012, master student, focusing on new structure of proton linac
  • Supported by:
    Supported by National Natural Science Foundation of China(No.11105166)

Abstract: Background

High energy section of drift tube linac (DTL) for China spallation neutron source (CSNS) is composed of 9 m cavity and 27 Quadrupole-D drift tubes, it is used to provide energy gain from 60 MeV to 80 MeV. The quadrupole-D magnet coil adopted SAKAE structure with compact and small aperture feature, maximum exciting current is 396 A. The drift tube shell is made of oxygen free copper and welded by the electron beam welding (EBW). High accuracy processing and magnetic measurements are required for this compact and small aperture drift tube.


The study aims to develop such a compact, small aperture and long effective length quadrupole-D magnet with high accuracy processing and magnetic measurement of a strong beam proton accelerator, and cone structure is first used for domestic drift tubes.


Quadrupole-D magnet is designed and optimized by code. Hall measurement and rotating coil measurement are carried out after the magnet is completed to keep the magnet qualified. Then, rotating coil measuremengts were carried out during the machining process to provide processing dimensions, and a precision rotating coil measurement system designed for drift tuning magnetic measurement is used to keep the drift tube qualified.


Quadrupole-D magnet and drift tube were developed for CSNS DTL, the effective length deviation is 2.6%, the integral field deviation is 2.2%, the field gradient deviation is 0.4% and the center deviation is better than 0.003, the higher-order harmonics are less than 3.5×10-3, 24 drift tubes magnetic center deviation is less than 0.03 mm, the magnet is in good condition after 9 h of running test.


DTL of CSNS run well with Quadrupole-D drift tubes, which are important for low energy intense beam proton accelerator.

Key words: Drift tube, Quadrupole magnet, Hall measurement, Rotating coil measurement, Integral field, Higher-order harmonics

CLC Number: 

  • TL503.8