A four-rod radio frequency quadruple (RFQ) accelerator is designed,manufactured,installed and commissioned for the Peking University Neutron Imaging Facility (PKUNIFTY).This 2699.6-mm-long RFQ accelerator with the mea...A four-rod radio frequency quadruple (RFQ) accelerator is designed,manufactured,installed and commissioned for the Peking University Neutron Imaging Facility (PKUNIFTY).This 2699.6-mm-long RFQ accelerator with the mean aperture radius of 3.88mm is operating at 201.5MHz in pulse mode.An inter-electrode voltage of 70kV is needed to accelerate the injected 50keV 40mA D+ ions up to 2MeV.We present the rf system,high rf power feeder design,lowver rf measurements and higher rf power test.Especially,the rf commissioning was carried out with rf power up to ~280 k W and duty factor of 4%.The measured x-ray spectrum shows that the rf inter-electrode voltage reaches 70.7 kV.It is found that the specific shunt impedance of the RFQ cavity reaches 52.7kΩ.m.展开更多
Several hundred keV fast neutron radiography(HKFNR)can be a complementary technique to common thermal neutron radiography(TNR)and several MeV fast neutron radiography(MFNR).We tested HKFNR on a 4.5 MV Van de Graaff ac...Several hundred keV fast neutron radiography(HKFNR)can be a complementary technique to common thermal neutron radiography(TNR)and several MeV fast neutron radiography(MFNR).We tested HKFNR on a 4.5 MV Van de Graaff accelerator,and the experimental results show that the spatial resolution of this technique is better than MFNR and close to TNR.Several hundred keV fast neutrons can penetrate some thermal neutron absorbers such as Cd,and it is feasible to investigate its use on some materials which are transparent to cold/thermal neutrons,such as aluminum,using this technique.展开更多
A 104-MHz ladder interdigital-H radio frequency quadrupole accelerator(T-IH-RFQ)is developed for applying RFQs to heavy ion implantation and accelerator-based mass spectroscopy in recent years at the Institute of Heav...A 104-MHz ladder interdigital-H radio frequency quadrupole accelerator(T-IH-RFQ)is developed for applying RFQs to heavy ion implantation and accelerator-based mass spectroscopy in recent years at the Institute of Heavy Ion Physics,Peking University.It could accelerate ions with a mass-to-charge ratio of less than 14,from 2.9 keV/u to 35.7 keV/u within a length of 1.1 m.The T-IH-RFQ cavity operating at H21(0)mode was constructed successfully.Based on a well designed rf power feeding system,the cavity was cold measured and tested with high rf power.In the case of cold measurement,the rf properties were obtained using a vector network analyzer with the help of a perturbation capacitor.During a high power test,the inter−electrode voltage was derived from the energy spectrum of x-rays measured by a high purity Ge detector.The results show that the specific shunt impedance of the T-IH-RFQ cavity reaches 178 kΩm,which could meet the requirements of beam dynamics design.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11079001 and 10775009.
文摘A four-rod radio frequency quadruple (RFQ) accelerator is designed,manufactured,installed and commissioned for the Peking University Neutron Imaging Facility (PKUNIFTY).This 2699.6-mm-long RFQ accelerator with the mean aperture radius of 3.88mm is operating at 201.5MHz in pulse mode.An inter-electrode voltage of 70kV is needed to accelerate the injected 50keV 40mA D+ ions up to 2MeV.We present the rf system,high rf power feeder design,lowver rf measurements and higher rf power test.Especially,the rf commissioning was carried out with rf power up to ~280 k W and duty factor of 4%.The measured x-ray spectrum shows that the rf inter-electrode voltage reaches 70.7 kV.It is found that the specific shunt impedance of the RFQ cavity reaches 52.7kΩ.m.
基金Supported by the National Basic Research Program of China under Grant No 2010CB833106。
文摘Several hundred keV fast neutron radiography(HKFNR)can be a complementary technique to common thermal neutron radiography(TNR)and several MeV fast neutron radiography(MFNR).We tested HKFNR on a 4.5 MV Van de Graaff accelerator,and the experimental results show that the spatial resolution of this technique is better than MFNR and close to TNR.Several hundred keV fast neutrons can penetrate some thermal neutron absorbers such as Cd,and it is feasible to investigate its use on some materials which are transparent to cold/thermal neutrons,such as aluminum,using this technique.
基金by the National Natural Science Foundation of China under Grant Nos 10775009 and 11079001.Y.C.Nie would like to thank the China Scholarship Council(CSC)for financial support when he was in Frankfurt.
文摘A 104-MHz ladder interdigital-H radio frequency quadrupole accelerator(T-IH-RFQ)is developed for applying RFQs to heavy ion implantation and accelerator-based mass spectroscopy in recent years at the Institute of Heavy Ion Physics,Peking University.It could accelerate ions with a mass-to-charge ratio of less than 14,from 2.9 keV/u to 35.7 keV/u within a length of 1.1 m.The T-IH-RFQ cavity operating at H21(0)mode was constructed successfully.Based on a well designed rf power feeding system,the cavity was cold measured and tested with high rf power.In the case of cold measurement,the rf properties were obtained using a vector network analyzer with the help of a perturbation capacitor.During a high power test,the inter−electrode voltage was derived from the energy spectrum of x-rays measured by a high purity Ge detector.The results show that the specific shunt impedance of the T-IH-RFQ cavity reaches 178 kΩm,which could meet the requirements of beam dynamics design.
