An ionic liquid ion source(ILIS)is a kind of high brightness ion source capable of providing high-speed positive or negative ion beams.This paper presents a miniaturized ILIS based on an array of porous metal strips.T...An ionic liquid ion source(ILIS)is a kind of high brightness ion source capable of providing high-speed positive or negative ion beams.This paper presents a miniaturized ILIS based on an array of porous metal strips.The porous emitter array,integrated with seven 10 mm long strips,is fabricated using wire electrical discharge machining(WEDM)combined with electrochemical etching.The assembled ILIS is 30 mm×30 mm×17.5 mm in size and weighs less than 25 g.A series of experiments,including anⅠ-Ⅴcharacteristic test,a retarding potential analyzer(RPA)test,and a spatial plume distribution test,have been conducted in vacuo to characterize the performance of the ILIS.Results show that the emitted current is up to about 800μA and ion transparency is as high as 94%.Besides,RPA curves reveal that the total fragmentation rate of the emitted particles accounts for 48.8%in positive mode and 59.8%in negative mode.Further,with the increase in applied acceleration voltage,the voltage loss rises while the energy efficiency decreases.It is also found that the plume perpendicular to the strips has a higher divergence than the one parallel to the strips.A numerical simulation by COMSOL reveals that the electric field distribution between the two electrodes results in such a spatial plume profile.展开更多
布里渊光频域分析技术(Brillouin Optical Frequency Domain Analysis,BOFDA)是近年来在国际上研发成功的一种分布式光纤传感技术,该技术已经开始被广泛应用于结构体和工业设备等的温度和应变感测,而最新的分布式应变测试技术可达到20c...布里渊光频域分析技术(Brillouin Optical Frequency Domain Analysis,BOFDA)是近年来在国际上研发成功的一种分布式光纤传感技术,该技术已经开始被广泛应用于结构体和工业设备等的温度和应变感测,而最新的分布式应变测试技术可达到20cm的空间分辨率和±2με的应变测试精度。文中首先介绍了BOFDA的工作原理以及技术验证,然后将该技术应用到钻孔灌注桩的桩身应变测量中,得到了桩身轴力及侧摩阻力的变化规律,并与钢筋应力计测得的桩身轴力数据做了对比,结果表明,BOFDA测试结果准确,可作为一种新型的桩基测试技术加以推广。展开更多
基金supported by National Natural Science Foundation of China(No.52075334)。
文摘An ionic liquid ion source(ILIS)is a kind of high brightness ion source capable of providing high-speed positive or negative ion beams.This paper presents a miniaturized ILIS based on an array of porous metal strips.The porous emitter array,integrated with seven 10 mm long strips,is fabricated using wire electrical discharge machining(WEDM)combined with electrochemical etching.The assembled ILIS is 30 mm×30 mm×17.5 mm in size and weighs less than 25 g.A series of experiments,including anⅠ-Ⅴcharacteristic test,a retarding potential analyzer(RPA)test,and a spatial plume distribution test,have been conducted in vacuo to characterize the performance of the ILIS.Results show that the emitted current is up to about 800μA and ion transparency is as high as 94%.Besides,RPA curves reveal that the total fragmentation rate of the emitted particles accounts for 48.8%in positive mode and 59.8%in negative mode.Further,with the increase in applied acceleration voltage,the voltage loss rises while the energy efficiency decreases.It is also found that the plume perpendicular to the strips has a higher divergence than the one parallel to the strips.A numerical simulation by COMSOL reveals that the electric field distribution between the two electrodes results in such a spatial plume profile.
文摘布里渊光频域分析技术(Brillouin Optical Frequency Domain Analysis,BOFDA)是近年来在国际上研发成功的一种分布式光纤传感技术,该技术已经开始被广泛应用于结构体和工业设备等的温度和应变感测,而最新的分布式应变测试技术可达到20cm的空间分辨率和±2με的应变测试精度。文中首先介绍了BOFDA的工作原理以及技术验证,然后将该技术应用到钻孔灌注桩的桩身应变测量中,得到了桩身轴力及侧摩阻力的变化规律,并与钢筋应力计测得的桩身轴力数据做了对比,结果表明,BOFDA测试结果准确,可作为一种新型的桩基测试技术加以推广。
