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1.
The power voltages of Photomultipliers (PMTs) at RIBLL LASCAR scintillator detector array are distributed between 900 V and 1 800 V irregularly. 392 CC123 modules are employed to supply high voltage for the PMT array. The CC123 module serves as PMT interface groupware package, and it can transform 12 V DC input voltage to ranges of 0~-2200 V for the PMT power supply corresponding to 0~ 5 V output voltage from the control board crate. The relation of PMT power supply with the output voltage of the control crate is shown in Fig.1.  相似文献   

2.
The LASCAR (Large Area Scattering Chamber at PABLL) scintillator detector array is developed to detect neutrons and charged particles from the reaction induced by, the RIBs from RIBLL. It consists of 8 scintillator plus light guide blocks. As shown in Fig.l, each block matches with 49 photomultipliers (PMTs) of 9214SB type from Electron Tubes Limited. Some technical improvements and the latest performance test of the 294 PMTs in 6 blocks of LASCAR are described in this report.  相似文献   

3.
描述了RIBLL终端大型探测器之一的大面积闪烁光纤阵列探测器(LASFA)的工作原理和结构特点, 报道了LASFA的研制以及单元性能的改进与测试。 LASFA具有很高的时间分辨和空间分辨能力, 可以很好地测量RIBLL终端各种轻带电粒子的信息。 The principles and structure characteristics of Large Area Scintillating Fiber Array(LASFA) detector at RIBLL (Radioactive Ion Beam Line in Lanzhou) are described. The development of LASFA and the characteristics of the scintillating fibers unit are reported. LASFA can be used to detect the light charged particles at RIBLL terminal due to its good time and spatial resolutions.  相似文献   

4.
The performance of superconducting nanowire single-photon detector (SNSPD) involving niobium nitride with the fan coupling antenna array is analyzed. The SNSPD has a high detection efficiency and counting rate. Hydrogen silsesquioxane and niobium nitride are filled in the gold grating deposited on the substrate in which the fan coupling antenna arrays are embedded. By changing the position of the fan coupling antenna array, the maximum area of optical intensity is obtained and the photon collection efficiency is increased by 26.5 times. The detection efficiency of SNSPD is improved without changing the detection speed. These parameters are important for designing a practical single-photon detector,  相似文献   

5.
A test result of a module for the collision centrality detector array (CCDA), a simple detector array for the event classification of the centrality, is presented. The CsI(Tl) module has PMTs on both ends to read out signals. The beam test results indicate that it provides a good light charged particles (LCP) identification and a reasonable energy resolution. The energy spectra of LCPs are compared with the GEANT simulation.  相似文献   

6.
对用电化学方法制备Si大孔阵列管坑工艺进行了初步探索。 通过对Si在KOH溶液中各向异性湿法蚀刻和在HF酸溶液中的电化学蚀刻过程中各种参数的摸索, 确定在室温下制备大孔阵列的最佳配比浓度, 蚀刻出符合要求的管坑阵列, 为进一步制备结构化闪烁屏奠定了实验基础。 The 3 D structures in silicon are increasingly coming to use in many fields. For example, the high resolution X ray digital imaging detector can be made by coupling CCD and the scintillating screen which is made by the array trenches filled with CsI(Tl). In the present work, we explored the technology of etching micro array on the n type silicon with high resistance. By studying the relative parameters of anisotropic etching of KOH and electro chemical etching of HF, the optimized concentration of HF was determined and the micro pore array trenches with 200 μm in depth were realized. The results establish an experimental base for further fabrication of the scintillating screen.  相似文献   

7.
In the Large High Altitude Air Shower Observatory (LHAASO) project, the one kilometer square extensive air shower array (KM2A) is the the largest detector array in terms of effective area. It consists of 5635 electromagnetic particle detectors (EDs) and 1221 muon detectors (MDs). Each ED is composed of 16 scintillator tiles readout by wavelength-shifting fibers that are bundled and attached by a 25 mm PMT. The design of the unit and its performances, such as photoelectron yield, time resolution and uniformity, are discussed in detail. An assembling scheme for the whole ED is established to guarantee the uniformity throughout all 16 tiles in a single ED and all EDs in mass production.  相似文献   

8.
A simulation of the properties of the shifting scintillator neutron detector using 6LiF/ZnS(Ag) scintillation screens is performed.The simulation results show that the light attenuation length of standard BC704 scintillator is about 0.65 mm.Its thermal neutron detection efficiency,gamma sensitivity and intrinsic spatial resolution can achieve around 50.0%,10 5and 0.18 mm(along X-axis) respectively.For the detector,air coupling position resolution is better than the silicone oil coupling.Some of the simulation results are compared with experimental results.They are in agreement.This work will be helpful for constructing neutron detector for high intensity powder diffractometer at Chinese spallation neutron source.  相似文献   

9.
A prototype array for the LHAASO-KM2A, which consists of 42 detector units and fully overlaps the ARGO-YBJ experiment, was set up at the Yangbajing cosmic ray observatory and has been in stable operation since Octoter 2010. The resulting performances of the KM2A electromagnetic particle detector prototypes fully meet the design requirements. Through hybrid observation of cosmic ray showers with the ARGO-YBJ experiment, the performances and long-term stability of the prototype array are tested and the results are consistent with expectation. The cosmic ray moon shadow observed by the prototype array is also presented.  相似文献   

10.
LHAASO-WCDA is a large ground-based water Cherenkov detector array planned to be built at ShangriLa, Yunnan Province, China. As a major component of the LHAASO project, the main purpose of LHAASO-WCDA is to survey the northern sky for very-high-energy(above 100 GeV) gamma ray sources and measure the spectrum. To gain full knowledge of the water Cherenkov technique and to investigate the engineering issues, a 9-cell detector array has been built at the Yang-Ba-Jing site, neighboring the ARGO-YBJ experiment. With the array, charge calibration methods for both low and high ranges of the PMT readout are studied, whose result shows that a precision at several percentages can be reached, which can satisfy the requirement of the detector array. During the long term operation, the charge calibration stability and environmental afection are studied; in this paper, the results are discussed. These calibration methods are proposed to be applied in the future LHAASO-WCDA project.  相似文献   

11.
针对低强度射线成像,自主研制了一种像元为0.1 mm高探测效率的液闪阵列屏.为此,基于倾斜刀口边缘响应的测量原理,建立了理论模拟方法和实验研究方法,对该液闪阵列屏开展了空间分辨性能研究.通过理论模拟,给出了液闪阵列屏在14 MeV中子和1.25 MeV伽马射线激发下的调制传递函数,并与像元为0.1,0.3和0.5 mm的闪烁纤维阵列屏进行了理论对比.在60Co伽马射线源上,对液闪阵列屏和像元为0.3和0.5 mm的两种国产闪烁纤维阵列屏进行了调制传递函数实测研究.理论模拟和实验结果一致,均表明液闪阵列的空间特性优于闪烁纤维阵列屏,而且具有更好的均匀性,对1.25 MeV伽马,空间分辨接近0.9 lp/mm,而其他两种纤维阵列屏仅达到0.5 lp/mm,对于14 MeV中子,液闪阵列屏的空间分辨可达到1.8 lp/mm.  相似文献   

12.
Processes attendant to the propagation of gammas in the sea water, in the wall of an immersed detector, and in a scintillator are simulated by the Monte Carlo method. The Compton spectra recorded by a deep-sea scintillation detector are simulated as a function of the wall thickness for two design versions of the detector. From the photoabsorption peak, the properties of wall materials, V-95 and steel 40, are compared. The background spectra of gammas generated in the scintillator are calculated. It is shown that a reasonable increase in the dimensions of the detector (without increasing those of the scintillator) improves the gamma detection efficiency.  相似文献   

13.
为测量中国锦屏地下实验室(China JinPing underground Laboratory,CJPL)极低通量的中子本底,需要建造大型快中子液体闪烁体探测器。建造探测器需要选用低放射性本底材料,并且化学性质稳定,不与液体闪烁体发生反应而影响液体闪烁体(EJ-335)的性能。为此,建造了小型液闪探测器,在其中分别放入聚四氟乙烯、无氧铜、氟橡胶、全氟醚橡胶这4种材料进行长期浸泡,并分别进行了如下测试:液闪长时间浸泡各种材料前后液闪的吸收光谱测试;用60Co γ源检测小型液闪探测器光产额随时间的变化情况;用Am-Be中子源检验探测器在浸泡前后的n-γ甄别性能。最终实验结果表明,聚四氟乙烯和全氟醚这2种材料与液闪有很好的兼容性,可作为大型快中子液闪探测器的容器和密封圈的备选材料。In order to measure the flux and spectrum of neutron background which is extremely low in China JinPing underground Laboratory (CJPL), liquid scintillator detector with large scale used to detect fast neutron need to be fabricated. Surrounding materials used in detector require the excellent performance, such as low radioactivity as well as stable chemical properties, which do not react with liquid scintillator, so as to avoid affecting the performance of detector. Polytetrafluoroethylene(PTFE), highly purified no-oxygen copper, fluororubber and perfluoroelastomer had been put in a small detector and soaked for a long time. The change of absorption spectrum and light yield along with time as well as the performance of n-γ discrimination after soaked were tested. The results show that PTFE and Perfluoroelastomer are compatible with liquid scintillator, which offers a reference for the selection of material used in container and seal of liquid scintillator detector used to detect fast neutron.  相似文献   

14.
The particle density in extensive air showers fluctuates at the ground level. These fluctuations, at the scale of the scintillator detector size (several meters), lead to the diversity of the individual detector responses. Therefore, small-scale fluctuations contribute to the error in the estimation of the primary energy by a ground array. This contribution is shown to be non-Gaussian. The impact on the primary energy spectrum measured by a ground array is estimated. It is argued that super-GZK events observed by AGASA experiment do not result from the energy overestimation, due to the small-scale fluctuations, of lower energy events. The text was submitted by the authors in English.  相似文献   

15.
为了比较3种闪烁体探测器的性能,利用蒙特卡罗方法计算了不同光纤直径的闪烁体阵列的空间分辨和能量沉积。模拟结果表明:相同光纤直径的普通液体闪烁体阵列空间分辨力比塑料闪烁体阵列提高了约0.1 mm,而氘代液体闪烁体阵列空间分辨力约为普通液体闪烁体阵列的1/2;富氢闪烁体的能量沉积比氘代闪烁体高;闪烁体光纤直径越小,分辨力越好;闪烁体越厚,光产额越高。  相似文献   

16.
The TRIUMF-ISAC Gamma-Ray Escape Suppressed Spectrometer is a high energy-resolution, high efficiency γ-ray detector array for radioactive beam experiments. It consists of high-purity germanium detectors with scintillator suppressors and waveform digitization. TIGRESS can operate in modes optimized for either maximum efficiency or for high peak-to-total, and can switch between these modes within a day. The digitized waveforms provide 6 mm FWHM position resolution for incident 137Cs γ rays. The array hosts a suite of auxilliary detectors for charged particles and neutrons.  相似文献   

17.
研究了基于硅光电倍增管(SiPM)双端读出的面积为10 cm ×10 cm的薄塑料闪烁体探测器的时间性能。239Pu放射源测试结果显示:(1)在多支SiPM串连读出方式下,随着SiPM数量的增加,探测器时间分辨逐渐变好;(2)在固定12支SiPM数量不变的情况下,并联支路越多,探测器时间分辨越差;(3)采用快时间塑料闪烁体并增加其厚度,可有效提高探测器时间分辨;(4)采用比束斑尺寸更大的塑料闪烁体,可有效提高探测器时间分辨的位置均匀性;(5)对于1 mm厚的EJ232塑料闪烁体探测器,在单端12支SiPM串行连接的情况下,可获得好于131 ps的时间分辨。这一研究对RIBLL2起始时间探测器的升级改造具有重要的指导意义。  相似文献   

18.
Summary An experiment is described in which air shower measurement are carried out by means of a ?track detector? placed in a test location near the center of a conventional array telescope currently in use for gamma-ray astronomy. This array, consisting of scintillators (GREX, operated at Haverah Park (U.K.) by the Department of Physics of the University of Leeds), provides, in the usual way, for each shower it selects, its own estimates of shower direction and shower particle density at the test location. Estimates of the muon density at the test location are provided by a large muon detector in operation nearby. The scintillator array triggers this muon detector and it is able to provide flexibly tailored trigger signals for the track detector. This detector named PLASTEX (acronym for Palermo Leeds Air Shower Tracking Experiment), consisting of tracking chambers above and below a thin sheet of lead, designed to provide data on charged particles incident from the air, on the stopping, scattering and multiplication of these particles in the lead sheet and on charged particles created in the lead sheet by shower photons. From these data estimates are derived of the densities and directional properties of the electrons, photons and muons striking the track detector. These results are to be compared with those given by the conventional detectors and with theoretical predictions given by simulations that are being carried out. The objective is to develop and assess optimal procedures for employing clusters of PLASTEX-type detectors as telescopes for the observation of UHE cosmic rays, including cosmic gammarays, over a very wide energy range. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.  相似文献   

19.
在星光Ⅲ实验装置上开展皮秒激光脉冲中子源实验,使用液体闪烁体探测器测得较好的中子信号,利用飞行时间法获得中子的能量/时间分布,通过示波器电压时间积分与阻抗之比得到不同能量段的电荷值。建立液体闪烁体探测器Geant4计算模型,通过实际打靶情况与标定情况下液体闪烁体探测器出光口收集到的可见光光子数之比,结合标定的灵敏度数据,获得液体闪烁体探测器对不同能量中子的灵敏度。计算得到源发射的中子能谱,能量在1 MeV以上的液体闪烁体探测器方向测得的中子产额为1.04108 sr-1。  相似文献   

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