Clover探测器的效率刻度
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摘要
HPGe探测器主要用于测量γ射线的能谱，其能量分辨一般为几个KeV，要比常用的NaI(T1)探测器好几十倍，使许多用NaI(T1)谱仪测量时无法分辨的谱线清楚地分开。因此，实际上绝大多数涉及复杂γ射线能谱的研究都是用高纯锗探测器进行的。
Clover型HPGe探测器由四块相同的HPGe晶体模切加工组装而成，较常用的由单块HPGe晶体组成的探测器，在角分辨能力、最高计数率、探测效率和抑制多普勒展宽等方面具有明显优势。
本论文在一个较宽的能量范围内对Clover探测器的γ射线探测效率利用通用蒙特卡罗程序MCNP4C进行了理论模拟，在低能部分进行了实验测量，并对理论模拟和实验测量的结果进行了比较，对Clover探测器的γ射线探测效率进行了刻度。
Clover的外面包裹着8块反康BGO晶体。16路BGO反康信号的逻辑OR信号作为数据获取系统的门信号，控制着信号的取舍。
实验利用Kmax多参数数据获取系统，以事件记录方式对Clover的四路输出信号同时进行记录。在离线数据处理中，对四路数据按事件方式进行处理，由对应于同一事件的各路能量相加，得出Clover的测试能谱和探测效率，并对由四块晶体间的cross-talk效应引起的事件探测效率增加做了分析。
HPGe detector, of which the energy resolution is much better than the normally used NaI(Tl) detector, is widly used to detect theγ-ray. The HPGe detector can distinguish two spectrums of which the difference between the two energy information is not distinct. Therefor, the Ge detector is applied to most researches related to complexγ-ray spectrum.
The Clover detector which contains four HPGe crystals has superiority in the aspects of angular resolution, the maximum count rate and energy resolution over the detector that contains only one crystal.
The efficiency is calibrated over a large range of energy by means of theoretical simulation and experiment. MCNP4C, a general Monte Carlo program, is used in the process of theoretical simulation. The results of the theoretical simulation and experiment is compared.
The Clover detector is surrounded by 8 crystals of BGO. Each crystal matches two photomultiplier tubes each of which generates an anti-compton signal. The logic OR of the 16 anti-compton signals is used to control the data acquisition system.
Kmax, which is a multiple parameters data acquisition system based on CAMAC -BUS , records the data of four output channels of the Clover detector event by event on the computer disk. The efficiency and energy spectrum of the Clover detector is obtained by addition of energy information corresponding to the same event in the process of off lining data processing. The increase of the efficiency resulted from the effect of cross section among the four crystals in one Clover is illuminated in the paper.
Clover型HPGe探测器由四块相同的HPGe晶体模切加工组装而成，较常用的由单块HPGe晶体组成的探测器，在角分辨能力、最高计数率、探测效率和抑制多普勒展宽等方面具有明显优势。
本论文在一个较宽的能量范围内对Clover探测器的γ射线探测效率利用通用蒙特卡罗程序MCNP4C进行了理论模拟，在低能部分进行了实验测量，并对理论模拟和实验测量的结果进行了比较，对Clover探测器的γ射线探测效率进行了刻度。
Clover的外面包裹着8块反康BGO晶体。16路BGO反康信号的逻辑OR信号作为数据获取系统的门信号，控制着信号的取舍。
实验利用Kmax多参数数据获取系统，以事件记录方式对Clover的四路输出信号同时进行记录。在离线数据处理中，对四路数据按事件方式进行处理，由对应于同一事件的各路能量相加，得出Clover的测试能谱和探测效率，并对由四块晶体间的cross-talk效应引起的事件探测效率增加做了分析。
HPGe detector, of which the energy resolution is much better than the normally used NaI(Tl) detector, is widly used to detect theγ-ray. The HPGe detector can distinguish two spectrums of which the difference between the two energy information is not distinct. Therefor, the Ge detector is applied to most researches related to complexγ-ray spectrum.
The Clover detector which contains four HPGe crystals has superiority in the aspects of angular resolution, the maximum count rate and energy resolution over the detector that contains only one crystal.
The efficiency is calibrated over a large range of energy by means of theoretical simulation and experiment. MCNP4C, a general Monte Carlo program, is used in the process of theoretical simulation. The results of the theoretical simulation and experiment is compared.
The Clover detector is surrounded by 8 crystals of BGO. Each crystal matches two photomultiplier tubes each of which generates an anti-compton signal. The logic OR of the 16 anti-compton signals is used to control the data acquisition system.
Kmax, which is a multiple parameters data acquisition system based on CAMAC -BUS , records the data of four output channels of the Clover detector event by event on the computer disk. The efficiency and energy spectrum of the Clover detector is obtained by addition of energy information corresponding to the same event in the process of off lining data processing. The increase of the efficiency resulted from the effect of cross section among the four crystals in one Clover is illuminated in the paper.
引文
[1] 复旦、清华、北大合编，原子核物理实验方法，原子能出版社，1994
[2] 丁洪林，核辐射探测器，核工业总公司研究生部(内部资料)，2003
[3] CLOVER 4×60×60 BC OPERATING MANUAL Canberra Eurisys S. A.
[4] 吕海江，蔡康松，焦铮，程和平，李铮，BGO晶体的性能研究，吉首大学学报(自然科学版)，Vol．27，No2，Mar．2006，pages58-60
[5] 雷祥国，郭应祥，周小红，张玉虎，刘忠，谢成营，王华磊，骆鹏，宋立涛，于海萍，郑勇，柳敏良，罗万居，何建军，轴对称型BGO反康屏蔽探测器研制，核电子学与探测技术，Vol．23，N03，May2003，Pages193-196
[6] 文万信，靳根明，BGO高能Y探测器性能测定与效率模拟，高能物理与核物理，Vol．26，No11，Nov．，2002，Pages1178-1183
[7] 金文绵，李素梅，MCNP3B使用手册，中国原子能科学研究院，1998
[8] 许淑艳，蒙特卡罗方法在实验核物理中的应用，北京：原子能出版社，1996
[9] 卢涵林，γ探测器的效率刻度和一些修正问题
[10] F. Y. Frank Chu, Coral. M Baglin, Nuclear chart index, 1998up
[11] 周春林，黎素芬，徐从学，基于反符合测量技术的HPGeY谱仪系统峰康比影响因素研究，核电子学与探测技术，2006／04，Vol．24 No．24
[12] 王崇杰，张爱莲，吕建洲，HPGeY探测器的点源效率函数及其参数确定，核技术，Vol29，No1 January 2006
[13] D. A. W. Bossus, J. J. J. M. Swagten and P. A. M. Kleinjans, Experience with a factory-calibrated HPGe detector, Nuclear Instruments and Methods in Physics Research A, 15 August 2006 Vol.564(02), P.ges 650-654
[14] Pavel Dryak and Petr Kovar, Experimental and MC determination of HPGe detector efficiency in the 40-2754 keV energy range for measuring point source geometry with the source-to-detector distance of 25 cm, Applied Radiation and Isotopes, October-November 2006 Vol.064(1011), P.ges 1346-1349
[15] 朱传新，陈渊，郭海萍，牟云峰，王新华，安力，高纯锗探测器探测效 率研究，核电子学与探测技术，Vol．26，No．4 March 2006
[16] J. L. Gutierrez-Villanueva, A. Martin-Martin, V. pena, M. Carcia-Talavera, C. Gomez, R. Pardos, Monte Carlo calibration of a portable HPGe detector to determine 137Cs inventories in soils, Applied Radiation and Isotopes, October-November 2006 Vol.064(1011), P.ge 1333
[17] H. A. El-Gharbawy, S. M. Metwally, T. Sharshar, T. Elnimr and H. M. Badran, Establishment of HPGe detector efficiency for point source including true coincidence correction, Nuclear Instruments and Methods in Physics Research A, 11 September 2005 Vol.550(1-2), Pages 201-211
[18] S. Ashra; A. Likar; T. Vidmar, Precise modeling of a coaxial HPGe detector, Nuclear Instruments and Methods in Physics Research A, 1999 Vol.438(2-3), Pages 421-428
[19] D. Karamanis, V. Lacoste, S. Andriamonje, Experimental and simulated ef ciency of HPGe detector with point-like and extended sources, Nuclear Instruments and Methods in Physics Research A, 2002 Vol.487(3), Pages 477-487
[20] 周丰群，杨景康，拓飞，易艳玲，孔祥忠，HPGey谱仪系统死时间校正方法的实验研究，高能物理与核物理，Vol．29，No．12，Doc．，2005
[21] companion to 93/94 catalog "Instruments & Systems for Nuclear Spectroscopy", EG&G ORTEC公司
[22] Euro-summary-02-06315, Zhong Qiping
[23] 张斌全，马吉增，程建平，刘立业，毛永，蒙特卡罗方法汁算用于低能光子测量的高纯锗探测器的效率，核电子学与探测技术，Vol．25，No．3，May 2005，Pages 274-277
[24] 张庆，古度意彦，HPGe探测器测量低能Y射线～(241)Am的研究，核电子学与探测技术，Vol．24，No．5，Sept 2004，Pages 498-501
[25] 方晓明，李欣年，碘化钠探测器和高纯锗探测器Y能谱仪性能比较，上海大学学报(自然科学版)，Vol．10，No．4，Aug．2004，Pages389-399
[26] 徐翠华，张庆，周强，任天山，耿秀生，HPGe探测效率和符合相加修正系数的蒙特卡罗计算，中国辐射卫生，Vol．13，No．2，June 2004，Pages92-94
[27] 李琦，连琦，常永福，夏兵，HPGe探测器的效率曲面研究，原子能科学技术，Vol．31，No3，May 2001，Pages254-157
[28] 彭朝华，李广生，陈细林，温书贤，低能HPGe探测器的绝对效率刻度，中国原子能科学研究院年报，1999年00期
[29] J. -M. Laborie, G. Le Petit, D. Abt, Monte Carlo calculation of the effciency response of a low-background well-type HPGe detector, 2002 Vol.479(2-3), Pages618-630
[30] Martin A. Ludington, Richard G. Helmer, High accuracy measurements and Monte Carlo calculations of the relative effciency curve of an HPGe detector from 433 to 2754 keV, Nuclear Instruments and Methods in Physics Research A, 2002 Vol.446(3), Pages506-521
[31] Z. Elekes, T. Belgya, G. L. Molnar, Absolute full-energy peak efciency calibration of Clover BGO detector system, Nuclear Instruments and Methods in Physics Research A, 2003 Vol.503(3), Pages580-588
[2] 丁洪林，核辐射探测器，核工业总公司研究生部(内部资料)，2003
[3] CLOVER 4×60×60 BC OPERATING MANUAL Canberra Eurisys S. A.
[4] 吕海江，蔡康松，焦铮，程和平，李铮，BGO晶体的性能研究，吉首大学学报(自然科学版)，Vol．27，No2，Mar．2006，pages58-60
[5] 雷祥国，郭应祥，周小红，张玉虎，刘忠，谢成营，王华磊，骆鹏，宋立涛，于海萍，郑勇，柳敏良，罗万居，何建军，轴对称型BGO反康屏蔽探测器研制，核电子学与探测技术，Vol．23，N03，May2003，Pages193-196
[6] 文万信，靳根明，BGO高能Y探测器性能测定与效率模拟，高能物理与核物理，Vol．26，No11，Nov．，2002，Pages1178-1183
[7] 金文绵，李素梅，MCNP3B使用手册，中国原子能科学研究院，1998
[8] 许淑艳，蒙特卡罗方法在实验核物理中的应用，北京：原子能出版社，1996
[9] 卢涵林，γ探测器的效率刻度和一些修正问题
[10] F. Y. Frank Chu, Coral. M Baglin, Nuclear chart index, 1998up
[11] 周春林，黎素芬，徐从学，基于反符合测量技术的HPGeY谱仪系统峰康比影响因素研究，核电子学与探测技术，2006／04，Vol．24 No．24
[12] 王崇杰，张爱莲，吕建洲，HPGeY探测器的点源效率函数及其参数确定，核技术，Vol29，No1 January 2006
[13] D. A. W. Bossus, J. J. J. M. Swagten and P. A. M. Kleinjans, Experience with a factory-calibrated HPGe detector, Nuclear Instruments and Methods in Physics Research A, 15 August 2006 Vol.564(02), P.ges 650-654
[14] Pavel Dryak and Petr Kovar, Experimental and MC determination of HPGe detector efficiency in the 40-2754 keV energy range for measuring point source geometry with the source-to-detector distance of 25 cm, Applied Radiation and Isotopes, October-November 2006 Vol.064(1011), P.ges 1346-1349
[15] 朱传新，陈渊，郭海萍，牟云峰，王新华，安力，高纯锗探测器探测效 率研究，核电子学与探测技术，Vol．26，No．4 March 2006
[16] J. L. Gutierrez-Villanueva, A. Martin-Martin, V. pena, M. Carcia-Talavera, C. Gomez, R. Pardos, Monte Carlo calibration of a portable HPGe detector to determine 137Cs inventories in soils, Applied Radiation and Isotopes, October-November 2006 Vol.064(1011), P.ge 1333
[17] H. A. El-Gharbawy, S. M. Metwally, T. Sharshar, T. Elnimr and H. M. Badran, Establishment of HPGe detector efficiency for point source including true coincidence correction, Nuclear Instruments and Methods in Physics Research A, 11 September 2005 Vol.550(1-2), Pages 201-211
[18] S. Ashra; A. Likar; T. Vidmar, Precise modeling of a coaxial HPGe detector, Nuclear Instruments and Methods in Physics Research A, 1999 Vol.438(2-3), Pages 421-428
[19] D. Karamanis, V. Lacoste, S. Andriamonje, Experimental and simulated ef ciency of HPGe detector with point-like and extended sources, Nuclear Instruments and Methods in Physics Research A, 2002 Vol.487(3), Pages 477-487
[20] 周丰群，杨景康，拓飞，易艳玲，孔祥忠，HPGey谱仪系统死时间校正方法的实验研究，高能物理与核物理，Vol．29，No．12，Doc．，2005
[21] companion to 93/94 catalog "Instruments & Systems for Nuclear Spectroscopy", EG&G ORTEC公司
[22] Euro-summary-02-06315, Zhong Qiping
[23] 张斌全，马吉增，程建平，刘立业，毛永，蒙特卡罗方法汁算用于低能光子测量的高纯锗探测器的效率，核电子学与探测技术，Vol．25，No．3，May 2005，Pages 274-277
[24] 张庆，古度意彦，HPGe探测器测量低能Y射线～(241)Am的研究，核电子学与探测技术，Vol．24，No．5，Sept 2004，Pages 498-501
[25] 方晓明，李欣年，碘化钠探测器和高纯锗探测器Y能谱仪性能比较，上海大学学报(自然科学版)，Vol．10，No．4，Aug．2004，Pages389-399
[26] 徐翠华，张庆，周强，任天山，耿秀生，HPGe探测效率和符合相加修正系数的蒙特卡罗计算，中国辐射卫生，Vol．13，No．2，June 2004，Pages92-94
[27] 李琦，连琦，常永福，夏兵，HPGe探测器的效率曲面研究，原子能科学技术，Vol．31，No3，May 2001，Pages254-157
[28] 彭朝华，李广生，陈细林，温书贤，低能HPGe探测器的绝对效率刻度，中国原子能科学研究院年报，1999年00期
[29] J. -M. Laborie, G. Le Petit, D. Abt, Monte Carlo calculation of the effciency response of a low-background well-type HPGe detector, 2002 Vol.479(2-3), Pages618-630
[30] Martin A. Ludington, Richard G. Helmer, High accuracy measurements and Monte Carlo calculations of the relative effciency curve of an HPGe detector from 433 to 2754 keV, Nuclear Instruments and Methods in Physics Research A, 2002 Vol.446(3), Pages506-521
[31] Z. Elekes, T. Belgya, G. L. Molnar, Absolute full-energy peak efciency calibration of Clover BGO detector system, Nuclear Instruments and Methods in Physics Research A, 2003 Vol.503(3), Pages580-588