The Peking University neutron imaging facility (PKUNIFTY), an RFQ-based neutron source, aims at developing industrial applications. During the past 3 y operation, some problems have appeared, such as RF sparking for t...The Peking University neutron imaging facility (PKUNIFTY), an RFQ-based neutron source, aims at developing industrial applications. During the past 3 y operation, some problems have appeared, such as RF sparking for the RFQ high power operation, full power level instability of RF transmitter, and the misalignment of RFQ electrodes assembling and deformation. The PKUNIFTY upgrade endeavors to adopt a modest inter-voltage beam dynamics design. The new beam dynamics design of 201.5MHz RFQ of PKUNIFTY, which accelerates 35mA of D+ from 50 keV to 2.0MeV at 10% duty factor, is performed. The averaged D+ beam will be about 3 mA. The source will deliver a fast neutron yield of 2.5x10(12) n/s via the deuteron-beryllium reaction, which is about 10 times higher than the current status.展开更多
A four-rod radio frequency quadruple （RFQ） cavity has been built for the Peking University Neutron Imaging Facility （PKUNIFTY）. The rf tuning of such a cavity is important to make the field distribution flat and t...A four-rod radio frequency quadruple （RFQ） cavity has been built for the Peking University Neutron Imaging Facility （PKUNIFTY）. The rf tuning of such a cavity is important to make the field distribution flat and to tune the cavity’s resonant frequency to its operating value. Plate tuners are used to tune the RFQ, which have an effect on both the cavity frequency and field distribution. The rf performance of the RFQ and the effect of plate tuners are simulated. Based on the simulation, a code RFQTUNING is designed, which gives a fast way to tune the cavity. With the aid of the code the cavity frequency is tuned to 201.5 MHz and the flatness deviation of the field distribution is reduced to less than 5%.展开更多
A mini-vane four-rod radio frequency quadruple (RFQ) accelerator has been built for neutron imaging. The RFQ will operate at 201.5 MHz, and its length is 2.7 m. The original electric field distribution along the elect...A mini-vane four-rod radio frequency quadruple (RFQ) accelerator has been built for neutron imaging. The RFQ will operate at 201.5 MHz, and its length is 2.7 m. The original electric field distribution along the electrodes is not flat. The resonant frequency needs to be tuned to the operating value. And the frequency needs to be compensated for temperature change during high power RF test and beam test. As tuning such a RFQ is difficult, plate tuners and stick tuners are designed. This paper will present the tuners design, the tuning procedure, and the RF properties of the RFQ.展开更多
基金Supported by the National Basic Research Program of China under Grant No 2014CB845503
文摘The Peking University neutron imaging facility (PKUNIFTY), an RFQ-based neutron source, aims at developing industrial applications. During the past 3 y operation, some problems have appeared, such as RF sparking for the RFQ high power operation, full power level instability of RF transmitter, and the misalignment of RFQ electrodes assembling and deformation. The PKUNIFTY upgrade endeavors to adopt a modest inter-voltage beam dynamics design. The new beam dynamics design of 201.5MHz RFQ of PKUNIFTY, which accelerates 35mA of D+ from 50 keV to 2.0MeV at 10% duty factor, is performed. The averaged D+ beam will be about 3 mA. The source will deliver a fast neutron yield of 2.5x10(12) n/s via the deuteron-beryllium reaction, which is about 10 times higher than the current status.
基金Supported by National Natural Science Foundation of China (10735020)National Basic Research Program of China(2010CB833106)
文摘A four-rod radio frequency quadruple （RFQ） cavity has been built for the Peking University Neutron Imaging Facility （PKUNIFTY）. The rf tuning of such a cavity is important to make the field distribution flat and to tune the cavity’s resonant frequency to its operating value. Plate tuners are used to tune the RFQ, which have an effect on both the cavity frequency and field distribution. The rf performance of the RFQ and the effect of plate tuners are simulated. Based on the simulation, a code RFQTUNING is designed, which gives a fast way to tune the cavity. With the aid of the code the cavity frequency is tuned to 201.5 MHz and the flatness deviation of the field distribution is reduced to less than 5%.
基金supported by the National Natural Science Foundation of China (Grant No. 107035020)the National Basic Research Program of China (Grant No. 2010CB833106)
文摘A mini-vane four-rod radio frequency quadruple (RFQ) accelerator has been built for neutron imaging. The RFQ will operate at 201.5 MHz, and its length is 2.7 m. The original electric field distribution along the electrodes is not flat. The resonant frequency needs to be tuned to the operating value. And the frequency needs to be compensated for temperature change during high power RF test and beam test. As tuning such a RFQ is difficult, plate tuners and stick tuners are designed. This paper will present the tuners design, the tuning procedure, and the RF properties of the RFQ.
