• Y.R. Lu, J.E. Chen, J.X. Fang, S.L. Gao, Z.Y. Guo, K.X. Liu, Y.C. Nie, X.Q. Yan, K. Zhu
  PKU/IHIP, Beijing

Funding: Supported by NSFC (10775009)
The methodology for low energy spread RFQ beam dynamics design has been studied for ¹⁴C+ AMS application. This paper will present a low energy beam dynamics and rf design for a new trapezoidal IH-RFQ. It will accelerate ¹⁴C from 40 keV to 500 keV with the length of 1.1 m; operate at 104 MHz with the rf peak power less than 27 kW. The transmission efficiency is better than 95% and the energy spread is as low as 0.6%. The rf structure design and its rf efficiency have been studied by electromagnetic simulation. It shows such trapezoidal IH-RFQ has higher operating frequency than normal IH-RFQ, and it will have more longitudinal accelerating efficiency.

• Y.R. Lu, J.E. Chen, J.X. Fang, S.L. Gao, Z.Y. Guo, M. Kang, S.X. Peng, Z. Wang, X.Q. Yan, M. Zhang, J. Zhao, K. Zhu
  PKU/IHIP, Beijing

Funding: supported by NSFC 10455001
Longer the RFQ length is, lower kinetic energy gain per unit length is; lower the injection energy DTL is, much higher accelerating efficiency is; more accelerating gaps at DTL entrance means stronger transverse focusing is needed for the beam. SFRFQ is such an intermediate structure, which combines RFQ and DTL together, it can increase the accelerating efficiency at RFQ high energy end by inserting gap acceleration between RFQ electrodes while provide strong focusing by RFQ focusing field. One prototype cavity has been manufactured and will be used as a post accelerator of ISR RFQ to accelerate O+ from 1 MeV to 1.6 MeV in 1meter. A code SFRFQCODEV1.0 was developed for the beam dynamics design. The rf conditioning and full rf power test has been carried out. The intervane or gap voltage have reached 86 kV at 29 kW with 1/6 duty cycle and repetition frequency 166 Hz. The initial beam test results will also be presented in this paper.