慢正电子寿命谱仪电子学系统原型机的研制
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摘要
慢正电子束技术(Slow Positron Technique)已经成为凝聚态物理学、化学和材料科学研究的主要研究工具之一,对材料表面微观缺陷的分析有明显的优越性。慢正电子湮没寿命测量主要利用慢正电子束流的单色性及能量连续可调等特点,研究缺陷在材料表面或近表面不同深度的分布信息。获得慢正电子湮没寿命测量起始时间的方法主要有两种:(1)利用慢正电子入射到样品时产生的二次电子获取时间起始信号;(2)利用对慢正电子束流进行脉冲化的脉冲调制信号作为起始信号。对慢正电子寿命谱仪而言,前者由于二次电子的能量和角度的分散性导致时间分辨率较低,目前最好可达350ps(FWHM);而后者的时间分辨率可达135-250ps(FWHM)。
     为打破国内材料科学的研究限制,追赶国际先进正电子研究手段的步伐,根据低能脉冲调制正电子束技术,中国科学技术大学的核固体物理实验室设计了一套脉冲式慢正电子寿命谱仪装置,其脉冲调制系统包括斩波器(Chopper)、预集束腔(Pre-Buncher)、主集束腔(Main-Buncher)和脉冲调制电子学系统。谱仪装置的设计目标是使连续的慢正电子束流经过三路信号的调制后,在样品处得到宽度为150-200ps的正电子窄脉冲,并实现慢正电子谱仪装置的寿命测量达到好于200ps的时间分辨。
     根据谱仪装置的设计原理并在参考赫尔辛基大学和北京高能所同类装置电子学系统的基础上,将谱仪电子学系统分为两个子系统:其一为脉冲调制电子学系统,该系统必须产生三路同步的高精度调制信号,来实现对慢正电子束的“筛选”和“聚焦”,以便在样品处得到宽度为150-200ps的正电子窄脉冲;同时,该系统必须提供与斩波器信号同步的时间起始信号。其二为高精度时间测量电子学系统,该系统必须对脉冲调制电子学系统给出的时间起始信号和探测器给出的时间停止信号进行高精度的时间间隔测量,以达到谱仪装置好于200ps的时间分辨。
     为了能够达到谱仪装置的设计目标,对电子学系统提出以下要求:
     1.斩波器信号为50MHz的脉冲信号,且具有大于5V的幅度、小于2ns的上升沿和下降沿、约7ns的脉冲宽度:预聚束腔和主聚束腔信号分别为频率50MHz和200MHz的正弦信号,且幅度都大于2V;
     2.三路信号间的相位晃动在60ps范围内;
     3.三路信号间的相位关系能够以小于50ps的步长进行调节;
     4.在20ns内测量精度好于64ps的时间测量。
     从上述要求可知,如何获得快边沿脉冲信号、保证各路信号间的低晃动及实现高精度的时间测量将是电子学系统设计的难点所在。
     针对设计要求及难点,在电子学系统设计中主要采用如下的技术路线:以一路时钟信号作为“源”信号,运用直接数字频率合成技术由此“源”信号产生一个频率可进行微调的高频信号,并通过对此高频信号进行分配分频得到三路信号,这是保证信号间相位稳定的关键;运用脉冲宽带放大技术获得大幅度快边沿信号,在获得快边沿信号的同时保证了引入较小的相位晃动;运用高精度的门延时技术实现信号间的相位调整;使用专用的TDC器件实现高精度的时间测量。
     本论文设计有如下几个主要特点:
     1.由一路信号通过变化得到三路信号的方法保证了在每次系统上电时信号间都能够有确定的相位关系;
     2.脉冲宽带放大技术获得大幅度快边沿信号,同时保证了对信号附加较小的晃动;
     3.精密门延时技术实现信号间相位的调整;
     4.专用的高精度时间测量器件TDC-GPX的使用,保证了系统的测量精度;
     5.内部集成DSP硬核大容量可编程逻辑器件(FPGA)的使用,为在线核信号数字处理提供研究平台,同时,为电荷修正的前沿定时方式时间测量作进一步的研究提供了测试平台,便于与恒比定时方式时间测量进行对比性实验;
     6.国内首台自行设计、以集成电路芯片为基础的脉冲式慢正电子寿命谱仪电子学系统原型机。系统的主要功能集成在NIM插件电路上实现,避免了使用大量的分立器件而存在的不兼容风险,同时,避免了由国外商业模块搭建的集成系统不容易根据实验条件改造和调节的缺点,增加了系统的灵活性。
     目前,本论文所设计的电子学系统原型机已经完成,并经过了一系列电子学测试,测试结果表明电子学系统设计满足设计指标要求,即将与慢正电子寿命谱仪一起进行联合实验测试。
Positron annihilation lifetime spectroscopy(PALS) is a sensitive probe of vacancy type defects in materials.Low-energy positron beam is accepted to be a useful tool for surface studies,such as nondestructive depth profiling of defects in surfaces and interfaces.There are two practical methods to obtain the start signal from a slow positron beam:(1) detecting the secondary electrons generated on the implantation of the positron into the sample as the start signal;(2) pulsing the positron beam by means of an appropriate radio-frequency fields and using the pulsing signal of the beam pulsing system as the start signal.The former method,although easier to implement,suffers usually from poor resolution due to the spread in secondary electron velocities.The best time resolution was 350 ps.The former technique gives good results(high counting efficiency and time resolution) but its complexity of installation and operation make it available in only a few laboratories.The time resolution was 135~350 ps.
     In order to break the limitations of the internal research for materials science and reach international advanced level,an apparatus of low-energy positron lifetime spectroscopy(LEPLS) based on beam pulsing method has recently been established in the University of Science and Technology of China(USTC),and the beam pulsing system consists of a reflection type chopper,a pre-buncher,a main-buncher,and a beam-pulsing electronics system.The design goal is to compress the DC beam into pulse duration of 150~200ps(FWHM) at the target and obtain time resolution with better than 200ps for lifetime measurement of LEPLS.
     According to the principle of LEPLS and referring to the similar apparatuses in the University of Helsinki and the Beijing High Energy Institute,the prototype electronics system is in two electronics subsystems:beam pulsing subsystem and time measurement subsystem.The beam pulsing subsystem generates three beam pulsing signals to chop and buncher the beam,and one "start" signal for lifetime measurement.The time measurement subsystem measures the time interval of the "start" and the "stop" signal from PMT.
     In order to achieve the design goals of LEPLS,the requirements for electronics system are as follows:
     1.Chopper signal is a 50 MHz pulse signal with amplitude greater than 5 V, edge time less than 2ns and pulse width about 7ns;pre-buncher signal is a 50MHz sine signal with amplitude greater than 2 V;main-buncher signal is a 200MHz sine signal with amplitude greater than 2 V.
     2.Phase jitter between three signals is less than 60ps.
     3.The step of phase adjust between three signals is less than 50ps.
     4.RMS of time measurement in range of 20ns is better than 64ps.
     According to the requirements above,the difficult points of the electronics system design are how to obtain the signal with fast edge-time,maintain the low jitter between three signals,and achieve good resolution of time interval measurement.
     Aiming at the design requirements and difficult points,the main technical features of this system are:generating three required signals from one source signal and using techniques of frequency synthesis,clock multi phase,precise delay and broadband pulse amplification to meet requirements of the waveform,frequency and phase relationship for the three beam pulsing signals,and using dedicated TDC IC for time interval measurement.
     Most key characters in this thesis are listed as follows:
     1.The method of generating three required signals from one source signal ensures to obtain certain phase between three signals at the electronics system power-up every time.
     2.Using the technique of broadband pulse amplification to obtain signal with fast edge-time,and add small additional jitter to the signal meantime.
     3.The precise phase adjust is achieved by using the technique of precise gate delay.
     4.A TDC-GPX chip with high precision for time interval measurement is used to maintain the good time resolution.
     5.A large capacity and high performance FPGA(Field Programmable Gate Array) device,by taking the advantages of its embedded DSP cores and other abundant resources,provides a platform to implement digital nuclear signals processing in hardware,and implement time measurement in leading edge timing with charge correction which is used to compare with time measurement in constant fraction timing.
     6.The first prototype of electronics system for LEPLS internally,based on IC,is self-designed and achieved.The core function of the electronics system is integrated in two NIM modules,which avoids using a large number of discrete devices with the risk for compatibility,and avoids the shortcoming that the integrated system constructed by the foreign commercial modules is not easy to transform in accordance with the experimental conditions.
     Presently,the prototype of electronics system has been produced.After a series of electronics test,the electronics system prototype is proved to meet the electronics requirements.Afterwards the in-filed test with LEPLS will be implemented.
引文
[1]Lande A.Quantum Mechanics,Sir Isaac Pitman & Sons.Ltd.,1951
    [2]Chao C Y.Phys.Res.,1930,36:1519
    [3]Anderson C D.Science,1932,76:238
    [4]Lemer R G and Trigg G L,Encyclopedia of Physics.Mass.,Addison-Wesley Pub,1981
    [5]韩荣典,叶邦角,翁惠民等。慢正电子束技术的应用与发展,物理学进展,1999,19(3):305-330
    [6]郁伟中。正电子物理及其应用,科学出版社,2003,P425
    [7]张天保,刘年庆.核探测器和核电子学会议资料汇编,北京:原子能出版社,1979,328
    [8]马雁云。慢正电子寿命谱仪的研制,中科院博士学位论文,2007
    [9]Schodlbauer D,Speer P,Triftshauser W.Nucl.Instrum.Methods,1988,B34:258
    [10]Lynn K G,Frieze W E,Schultz P J.Phys.Rev.Lett.,1984,52:1137
    [11]Stanislaw S,Mihail P P,Kelvin G L.Review of Scientific Instruments,2002,73:147
    [12]Suzuki R,Kobayashi Y,Mikado T,et al.Japanese Journal of Applied Physics,1991,30(3B):L532
    [1]K Fallstr(o|¨)m,T Laine.Construction of the Helsinki University of Technology(HUT) pulsed positron beam,Applied Surface Science,149(1999) 44 - 48
    [2]Antti Laakso.Construction of a pulsing system for low-energy positrons,Dissertation for the degree of Doctor,Helsinki University of Technology,2005
    [3]Antti Pelli.Implementation and testing of high voltage system for pulsed low-energy positron beam and conventional positron beam studies in InN,Dissertation for the degree of Doctor,Helsinki University of Technology,2007
    [4]马雁云,裴士伦,曹兴宗等。北京慢正电子强束流束团化系统设计,高能物理与核物理,2006,第30卷第2期,
    [5]马雁云。慢正电子寿命谱仪的研制,中科院博士学位论文,2007
    [6]WANG Bao-Yi,Ma Yan-Yun,WANG Ping,et al.Development and application of the intense slow positron beam at IHEP,Chinese Physics C,2008,Vol.32,No.2
    [7]Gao Chuan Bo,Xiong Tao,Xi Chuan-Ying.Simulation of time bunching for a pulsed positron beam,Chinese Physics B,2008,Vol.17,No.11
    [8]A V Akindinov,A Alici,F Anselmo,et al.Design aspects and prototype test of a very precise TDC system implemented for the Multigap RPC of the ALICE-TOF,Nuclear Instruments and Methods in Physics Research A 533(2004) 178 - 182
    [9]J Schambach for the STAR Collaboration TOF Group.Proposed STAR Time of Flight Readout Electronics and DAQ,Computing in High Energy and Nuclear Physics,LaJolla,California,March 2003
    [10]郭建华,刘树彬,周世龙。 BESIII TOF前端读出电子学系统原型设计和实验结果,高能物理与核物理,2006年第30卷第8期
    [1]D Sch(o|¨)dlbauer,P Speer,G K(o|¨)gel,et al.Nucl.Instrum.& Methods,B34(1988) 258
    [2]Suzuki R,Kobayashi Y,Mikado T,et al.Japanese Journal of Applied Physics,1991,30(3B):L532
    [3]K Fallstr(o|¨)m,T Laine.Applied Surface Science,149(1999) 44 - 48
    [4]Gao Chuan Bo,Xiong Tao,Xi Chuan-Ying.Simulation of time bunching for a pulsed positron beam,Chinese Physics B,2008,Vol.17,No.11
    [5]Zhang L B,Yao Z X,Ji C and Zhang Z J.1997,Oil Geo - physical Prospecting,32 654(in Chinese)
    [6]Rob A Rutenbar.Circuits and Devices Magazine,IEEE,Volume 5,Issue 1,Jan.1989Page(s):19 - 26
    [7]Genetic Algorithm and Direct Search Toolbox~(TM)User's Guide,Ver.2.0,2005,MathWorks,Inc.,Natick,MA,U.S.A.
    [8]杨檍,鲍景福。现代频率合成技术的研究进展,电讯技术,2007年47卷2期
    [9]薛文。DDS任意波形发生器的设计与实现,南京理工大学,硕士学位论文,2004年
    [10]王雅君,吴玉广,黎文福。基于FPGA的新的DDS+PLL时钟发生器,中国集成电路,2006年15卷8期
    [11]AD9912 datasheet,Rev.0,2007,Analog Devices,Inc.
    [12]DDS-Based Clock Jitter Performance vs.DAC Reconstruction Filter Performance,Analog Devices,Inc.,AN-837,Rev.0,2006
    [13]Direct Digital Synthesizers in Clocking Applications Time Jitter in Direct Digital Synthesizer-Based Clocking Systems,Analog Devices,Inc.,AN-823
    [14]AD9912 Evaluation Board,Rev.0,2008,Analog Devices,Inc.
    [15]刘抒珍,童子权,任丽军,刘小红。DDS波形合成技术中低通椭圆滤波器的设计,哈尔滨理工大学学报,2004年9卷5期
    [16]AD9510datasheet,Rev.A,2005,Analog Devices,Inc.
    [17]Evaluation Board for AD9510,Rev.0,2005,Analog Devices,Inc.
    [18]张岳华,虞孝麒,胡元峰等。两个不同原理的延时功能NIM插件的研制,核电子学与探测技术,2007,27(1):70
    [19]彭能岭,虞孝麒,胡元峰。基于FPGA的8通道高速计数器的研制,核电子学与探测技术,2006,26(6):821.
    [20]MC100EP195 datasheet,Rev.16,2006,ON Semiconductor,Inc.
    [21]Jim Williams.High Speed Amplifier Techniques,Linear Technology App,Note 47,1991
    [22]Y W YEAP.Ultra Widband Signal Generation,Microwave Journal,2005,9
    [23]Liu Jinyuan,Shan Bing,Chang Zenghu.High voltage fast ramp pulse generation using avalanche transistor,Review of Scientific Instruments,1998
    [24]J Ha,C Nguyen.A New Ultra-Wideband,Ultra-Short Monocycle Pulse Generator With Reduced Ringing,IEEE Microwave and Wireless Components Letters,2002,12(6):206
    [25]何小艇。高速脉冲技术,杭州:浙江大学出版社,1990
    [26]钱卫明,阴泽杰。一种通用可编程的高速ECL时钟成形和分频模块,核电子学与探测技术,2001,21(1):18
    [27]Clock(CLK) Jitter and Phase Noise Conversion,Application note 3359,2004,Maxim Integrated Products,Inc.
    [28]Phase Noise and Jitter - A Primer for Digital Designers,EE Design,2003,Zarlink Semiconductor
    [29]Jitter and Signal Noise in Frequency Sources,Raltron Electronics corp.
    [30]THS3201datasheet,SLOS416A-JUNE 2003-REVISED JANUARY 2004,Texas Instruments incorporated
    [31]MC10E1651 datasheet,Rev.8,2006,ON Semiconductor,Inc.
    [32]Model 567 Operating and Service Manual,Advanced Measurement Technology,Inc.,2002
    [33]Trump 8k/2k Hardware Manual,Advanced Measurement Technology,Inc.,2002
    [34]康华光。电子技术基础(第四版)模拟部分,北京:高等教育出版社,2006
    [35]ZHL-1A datasheet,Rev.1,2007,Mini-Circuits
    [36]ZHL-1-2W datasheet,Rev.OR,2007,Mini-Circuits
    [37]马雁云。慢正电子寿命谱仪的研制,中科院博士学位论文,2007
    [38]Cyclone Device Handbook,C5V1-1.4,2003,Altera Corporation
    [39]吴秀清,周荷琴。微型计算机原理与接口技术(第二版),合肥:中国科学技术大学出版社,2002
    [40]CDCF5801A datasheet,SCAS813A-AUGUST 2005- REVISED DECEMBER 2005,Texas Instruments incorporated
    [41]Configuration Handbook,CF5V 1-2.2,August 2005,Altera Corporation
    [42]MAX3232 datasheet,Rev.11,2007,Maxim Integrated Products,Inc.
    [43]Antti Pelli.Implementation and testing of high voltage system for pulsed low-energy positron beam and conventional positron beam studies in InN,Dissertation for the degree of Doctor,Helsinki University of Technology,2007
    [44]余昌盛,许力。基于C++Builder 6的串口通信程序实现方法研究,机电工程,2004年21卷7期
    [1]谢一冈,陈昌,王曼等。粒子探测器与数据获取,北京:科学出版社.2003
    [2]郭建华。北京谱仪(BESIII)飞行时间读出电子学系统设计与实现,中国科学技术大学博士学位论文,2005
    [3]虞孝麒。核电子学方法,中国科技大学,1996
    [4]安琪。粒子物理实验中的精密时间间隔测量,核技术,2006年第29卷第6期
    [5]TDC-GPX datasheet,2007,ACAM
    [6]TDC-GPX Evaluation System,2005,ACAM
    [7]TDCoGPX-PLL Regulation Circuits,Application Note No.13,ACAM
    [8]TLK1501 datasheet,SLLS428F-JUNE 2000-REVISED JANUARY 2004,Texas Instruments incorporated
    [9]AFBR-53D5Z datasheet,V02-0457EN,May 25,2007,Avago Technologies
    [10]许永和.EZ-USB FX系列单片机USB外围设备设计与应用,北京:北京航空航天大学 出版社,2002
    [11]Universal Serial Specification Revision 2.0
    [12]CY7C68013 datasheet,Revised January 15,2002,Cypress Semiconductor Corporation
    [13]EZ-USB FX2 Technical Reference Manual,Rev.A,2008,Cypress Semiconductor Corporation
    [14]EZ-Loader Design Notes,1998,Cypress Semiconductor Corporation
    [15]赵豫斌,江晓山。BESIII漂移室电子学时间测量电路的三种方案比较,核电子学与探测技术,2007年第27卷第2期
    [16]MAX9601 datasheet,Rev.1,2002,Maxim Integrated
    [17]MC 100EP195 datasheet,Rev.16,2006,ON Semiconductor,Inc.
    [18]MC 100EL05 datasheet,Rev.3,2006,ON Semiconductor,Inc.
    [19]MC100LVEP11 datasheet,Rev.11,2006,ON Semiconductor,Inc.
    [20]DAC7612 datasheet,SBAS106,1999,Burr-Brown Corporation
    [21]虞孝麒。核电子学方法,中国科学技术大学,内部教材
    [22]李勇,苏弘,千奕。多道时间幅度变换电路的设计,核电子学与探测技术,2006年第26卷第4期
    [23]AD8066 datasheet,Rev.G,2006,Analog Devices,Inc.
    [24]AD9233 datasheet,Rev.A,2006,Analog Devices,Inc.
    [25]Fully Differential-Amplifiers,James Karki,Texas Instruments,Application Report,SLOA054D,January 2002
    [26]AD8138 datasheet,Rev.F,2006,Analog Devices,Inc.
    [27]OPA227 datasheet,SBOS110A-MAY 1998-REVISED JANUARY 2005,Texas Instruments incorporated
    [28]REF3220 datasheet,SBVS058B-JUNE 2005-REVISED FEBRUARY 2006,Texas Instruments incorporated
    [29]Cyclone Ⅲ Device Handbook,CIII5V1-2.0,2008,Altera Corporation
    [30]Interfacing to High Speed ADCs via SPI,Rev.A,2007,Analog Devices,Inc.
    [31]Configuration Handbook,2008,Altera Corporation
    [32]TPS54383 datasheet,SLUS774B-AUGUST 2007-REVISED OCTOBER 2007,Texas Instruments incorporated
    [33]NCP566 datasheet,Rev.1,2007,ON Semiconductor,Inc.
    [34]LM333T datasheet,DS009065,1999,National Semiconductor Corporation
    [35]LM1084 datasheet,2005,National Semiconductor Corporation
    [36]MA3J147 datasheet,Panasonic
    [37]武安河,邰铭,于洪涛。Windows 2000/XP WDM设备驱动程序开发,北京:电子工业出版社,2003
    [38]WinDriver v6.03 User's Guide,Jungo Ltd,2003
    [1]刘莉,王晓军。电磁兼容设计中的地线干扰与抑制,现代电子技术,2005,20
    [2]古树忠。电子电路应用系统的接地问题及对策,电子工艺技术,2001,1
    [3]吕俊霞。电子设备的地线干扰及其抑制方法,印制电路信息,2007,VOL 1
    [4]R Suzuki,T Ohdaira,T Mikado.A positron lifetime spectroscopy apparatus for surface and near-surface positronium experiments.Radiation Physics and Chemistry,58(2000) 603 - 606
    [5]Antti Pelli,Antti Laakso,Klaus Ryts(o|¨)1(a|¨),et al.HV Design of a Pulsed Lifetime Beam with a Grounded Sample
    [6]Antti Laakso.Construction of a pulsing system for low-energy positrons.Dissertation 133(2005) Finland
    [7]Chunqing He,Eisaku Hamada,et al.Development on a pulsed slow-positron beam:Moderator and bunching signal waveform.Nuclear Instruments and Methods in Physics Research B,211(2003) 571 - 576
    [8]E Hamada,N Oshima,T Suzuki,et al.New system for a pulsed slow-positron beam using a radioisotope.Radiation Physics and Chemistry,58(2000) 771 - 775
    [9]Howard Matis,Dick Jared.Grounding Requirements Document for STAR,Controlled STAR Note 202A,May 14,1997
    [1]TDS3054B Manual,Tektronix,Inc.
    [2]Andy Kuo,Touraj Farahmand,et al.Jitter Models and Measurement Methods for High-Speed Serial Interconnects,ITC International Test Conference,2004,IEEE
    [3]DB463 Delay Box,Advanced Measurement Technology,Inc.
    [4]Model 567 Operating and Service Manual,Advanced Measurement Technology,Inc.
    [5]Trump 8k/2k Hardware Manual,Advanced Measurement Technology,Inc.
    [6]Agilent 33250A Manual,Agilent,Inc.
    [7]MC100EP195 datasheet,Rev.16,2006,ON Semiconductor,Inc.
    [8]郭建华,刘树彬,封常青等。BESIII飞行时间计数器前端电子学测试系统设计,核技术,2007,30(7):610-614
    [9]TDC-GPX datasheet,2007,ACAM
    [10]TLK1501 datasheet,SLLS428F-JUNE 2000-REVISED JANUARY 2004,Texas Instruments incorporated

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