A waterproof nanocrystalline soft magnetic alloy core with a size of O.D.850 mm×I.D.316 mm×H.25 mm for radio frequency acceleration was successfully developed by winding 18μm 1k107b MA ribbons.Theμ'_(p...A waterproof nanocrystalline soft magnetic alloy core with a size of O.D.850 mm×I.D.316 mm×H.25 mm for radio frequency acceleration was successfully developed by winding 18μm 1k107b MA ribbons.Theμ'_(p)Qf products reached 7.5,10,and 12 GHz at 1,3,and 5 MHz,respectively.Theμ'_(p)Qf products of the MA core(O.D.250 mm×I.D.100 mm×H.25 mm)manufactured using a 13μm MA ribbon further increased by 30%.Detailed improvements on the MA core manufacture process are discussed herein.Continuous high-power tests on the new MA cores demonstrated its good performance of waterproofness,particularly its stability of highμ'_(p)Qf products.The MA core with highμ'pQf product and large size can operate under a high average RF power,high electric field,and in deionized water,which will be used in the China Spallation Neutron Source PhaseⅡ(CSNS-Ⅱ).展开更多
In this work, samples of carbon/carbon(C/C) and chemical vapor deposited(CVD) SiC-coated C/C samples were investigated to understand the AO damage mechanism in low Earth orbit(LEO) environment. The ground-based simula...In this work, samples of carbon/carbon(C/C) and chemical vapor deposited(CVD) SiC-coated C/C samples were investigated to understand the AO damage mechanism in low Earth orbit(LEO) environment. The ground-based simulated atomic oxygen(AO) generator was employed. Results indicate that the CVD SiC coating exhibited improved radiation resistance properties against AO radiation as evidenced by a 16%better strength retention ratio, 60% less mass ablation, and increased strength stability. The magnitude of these influences affected the surface morphology, as observed by scanning electron microscopy(SEM)and surface resistance meter test results. The variations in the surface constituents were confirmed by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) results. The main products left on surface after AO exposure are SiO2 and SiCxOyfilm. Additionally, Si atoms are found to be the preferential reacting element in the SiC coating, and this process is accompanied by graphite precipitation, grain growth, and crack necking. Also, the damage mechanism of the AO-exposed SiC coating was revealed and is discussed.展开更多
基金supported by the funds of the National Natural Science Foundation of China (Nos. 11175194, 11875270, and U1832210)Youth Innovation Promotion Association CAS (No. 2018015)Guangdong Basic and Applied Basic Research Foundation (No.2019B1515120046)
文摘A waterproof nanocrystalline soft magnetic alloy core with a size of O.D.850 mm×I.D.316 mm×H.25 mm for radio frequency acceleration was successfully developed by winding 18μm 1k107b MA ribbons.Theμ'_(p)Qf products reached 7.5,10,and 12 GHz at 1,3,and 5 MHz,respectively.Theμ'_(p)Qf products of the MA core(O.D.250 mm×I.D.100 mm×H.25 mm)manufactured using a 13μm MA ribbon further increased by 30%.Detailed improvements on the MA core manufacture process are discussed herein.Continuous high-power tests on the new MA cores demonstrated its good performance of waterproofness,particularly its stability of highμ'_(p)Qf products.The MA core with highμ'pQf product and large size can operate under a high average RF power,high electric field,and in deionized water,which will be used in the China Spallation Neutron Source PhaseⅡ(CSNS-Ⅱ).
基金funded by the National Natural Science Foundation of China (Nos. 51632007 and No. 51672218 and No. 51821091)the National Key R&D Program of China (Grant No.2017YFB1103500)
文摘In this work, samples of carbon/carbon(C/C) and chemical vapor deposited(CVD) SiC-coated C/C samples were investigated to understand the AO damage mechanism in low Earth orbit(LEO) environment. The ground-based simulated atomic oxygen(AO) generator was employed. Results indicate that the CVD SiC coating exhibited improved radiation resistance properties against AO radiation as evidenced by a 16%better strength retention ratio, 60% less mass ablation, and increased strength stability. The magnitude of these influences affected the surface morphology, as observed by scanning electron microscopy(SEM)and surface resistance meter test results. The variations in the surface constituents were confirmed by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) results. The main products left on surface after AO exposure are SiO2 and SiCxOyfilm. Additionally, Si atoms are found to be the preferential reacting element in the SiC coating, and this process is accompanied by graphite precipitation, grain growth, and crack necking. Also, the damage mechanism of the AO-exposed SiC coating was revealed and is discussed.
