IHEP Beijing, Beijing
PKU/IHIP, Beijing
CIAE, Beijing
A high-duty factor proton RFQ accelerator has been constructed at IHEP, Beijing for the basic study of Accelerator Driven Subcritical System. The ADS basic study is supported by a national program for nuclear waste transmutation which is regarded essential for the rapid development of nuclear power plants in China. In the initial commissioning of the 3.5MeV RFQ with an ECR ion source showed a nice performance with a transmission rate about 93% with an output beam of 46mA. The 352MHz RFQ is design for CW operation with the RF power source from LEP-II of CERN. This paper presents the beam commissioning and recent progress in high-duty factor operation from 7% to 15%.
PKU/IHIP, Beijing
Funding: supported by NSFC (19775009)
A trapezoidal IH-RFQ (T-IH-RFQ) is being built to accelerate 14C^+ from 40 keV to 500 keV, motivated by RFQ based 14C AMS application at Peking University. The last design of beam dynamics and the optimized results of RF structure will be presented in this paper. The length of the cavity is about 1.1m operating at {10}4MHz, with a designed transmission efficiency of more than 97%. A special feature is that the RFQ output beam energy spread is as low as 0.6% approached by the method of internal discrete bunching. On the other hand, the new RF cavity structure T-IH-RFQ was proposed for the beam dynamics design, which has higher resonant frequency than traditional four rods RFQ and IH-RFQ at the same transverse dimension. Microwave Studio (MWS) simulations have been performed to study the field distribution and power consumption characteristic of this T-IH-RFQ. The specific shunt impedance and the quality factor have been optimized. Those details will be given.
PKU/IHIP, Beijing
Funding: work supported by NSFC(10805003,10855001)
The beam commissioning of Separated Function RFQ (SFRFQ) accelerator, which can gain high accelerating efficiency and enough focusing strength for low energy high current beam, is presented. In order to demonstrate the feasibilities of this novel accelerator, a prototype cavity was designed and constructed. The O+ beam was accelerated from 1MeV to 1.6MeV by SFRFQ cavity. A triplet was constructed for the transverse beam matching between the 1MeV ISR-RFQ 1000 and SFRFQ. A capacitance frequency tuning system and RF phase shifter were used to keep SFRFQ cavity working at the same frequency of ISR RFQ at the right phase. The whole RFQ accelerator system and the preliminary beam test results are presented in this paper.