新型行波离轴离子传输器的设计与表征  

Design and Characterization of a Novel Traveling-wave Off-axis Ion Transmitter

作　　者：曾鹏宇 何星亮 郭星 邓辅龙 孙红恩 吴斌[1] 赵忠俊[1,2] 段忆翔 ZENG Peng-yu;HE Xing-liang;GUO Xing;DENG Fu-long;SUN Hong-en;WU Bin;ZHAO Zhong-jun;DUAN Yi-xiang(School of Mechanical Engineering,Sichuan University,Chengdu 610044,China;Aliben Science&Technology Co.,Ltd,Chengdu 611930,China)

机构地区：[1]四川大学机械工程学院,四川成都610044 [2]成都艾立本科技有限公司,四川成都611930

出　　处：《质谱学报》2024年第4期510-518,I0003,共10页Journal of Chinese Mass Spectrometry Society

基　　金：四川省科技计划项目(2022YFG0082)。

摘　　要：为滤除质谱系统中来自电喷雾电离源(ESI)的大量中性污染物和带电液滴,提高质谱系统的灵敏度、信噪比和耐用性,出现了一种基于行波堆叠环的离轴离子传输器。根据其结构特性,本研究设计了对应的行波射频耦合供电电源及测控系统。采用以太网通讯协议控制现场可编程逻辑门阵列(FPGA)以实现全电路的信号控制和发生,通过12位模数转换器(ADC)和16位数模转换器(DAC)实现8通道行波幅值的监控,并设计双平面变压器耦合电路,在堆叠环上成功实现了行波提供轴向动能的效果。测试了硬件系统在离轴传输结构上的电参数稳定性和精度,结果表明:行波电源可控电压范围为0.1~100 V;行波电源脉冲频率范围为0~400 kHz;直流转直流(DC-DC)直流高压纹波小于0.03%;行波高低电压全量程检测绝对误差小于0.03 V;行波高低电压控制输出全量程绝对误差小于0.04 V;多通道射频峰峰值电压差小于1 V;行波上升下降时间均小于30 ns;射频和行波波形平滑,该电源系统能够满足堆叠环离轴传输器的电源设计要求。在粗真空下,采用利血平离子对离轴结构的性能进行测试,实验结果为行波堆叠环结构的离子传输和离轴分离提供了基本理解,对高信噪比质谱系统的研发具有重要价值。To enhance the sensitivity,signal-to-noise ratio and durance of electrospray mass spectrometer,an off-axis ion guide combining a traveling-wave(TW)stacked-ring and a shaped ion funnel has been designed,which is capable of filtering out the neutral contaminants and charged droplets entrained in the electrospray plume.According to its structural characteristics,the corresponding TW and radio frequency(RF)coupling power supply and measurement as well as control system were designed.Customizable Ethernet communication protocol was used to control the field-programmable logic gate array(FPGA)for full-circuit signal control and generation,and an 8-channel traveling-wave amplitude monitoring was achieved through a 12-bit analog-to-digital converter(ADC)and a 16-bit digital-to-analog converter(DAC).In addition,dual-plane transformer coupling circuit was designed.The use of traveling wave changed the central reference frame of the RF,achieving the purpose of programmed RF and the effect of TW in the stacked-ring to provide axial kinetic energy.The stability and accuracy of the electrical parameters of the hardware system on the off-axis transmission structure were tested.The results showed that the controllable voltage range of TW power supply is 0.1-100 V and the controlled DC power supply’s full range detection and control absolute error are less than 0.04 V.The frequency of TW up to 400 kHz,both rising edge and falling edge are less than 30 ns.Furthermore,the waveforms of TW,RF and post-coupling waveform are sufficiently smooth.The test results also showed that the performance of the power supply and measurement and control system are stable and reliable,and their accuracy and range can satisfy the design requirements.Then,the performance of off-axis structure was tested under rough vacuum using reserpine ions.It was found that the reference voltage difference between the upper and lower traveling-waves(the voltage which the ions were extracted),the voltage of the upper traveling-waves,and the traveling-wave duty cyc

关 键 词：质谱 离轴离子传输器 耦合电源 

分 类 号：O657.63[理学—分析化学]