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钨酸铅(PbWO4)闪烁晶体研究进展 总被引:2,自引:1,他引:1
钨酸铅(PbWO4)闪烁晶体是拟使用于西欧大型强子对撞机(LHC)中精密电磁量能器量有希望的候选者,本文概要介绍了近年来国际上对于钨酸铅晶体的研究进展。包括它的闪烁性能、发光机制、辐照硬度和杂质效应等。本文最后列出了欧洲核子研究中心(CERN)的CCC组最近对75根大尺寸PWO晶体综合测试的统计结果。这有助于建立批量生产PWO晶体的质量监控方法。 相似文献
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无机闪烁晶体及其应用 总被引:4,自引:0,他引:4
本世纪40年代后期发现NaI:Tl晶体具有优良的闪烁特性后,NaI:Tl被广泛应用于X射线和γ射线的探测技术。随着核探测技术在医学、物理、化学、地质勘探等科学技术领域中的发展,一系列无机闪烁晶体,如BGO、CWO、CsI:Tl、CsI等相继问世,并在这些领域中得到了应用。近年来,为了提高核医疗设备如PET等的性能和建造大型高能物理实验装置,如SSC和LHC,对新型快速、高密度、耐辐照的无机闪烁晶体 相似文献
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闪烁晶体材料的研究进展 总被引:1,自引:0,他引:1
闪烁晶体用于X射线和γ射线等高能粒子探测,在分子医学成像、高能物理、核物理、安全检查、材料无损探伤和地质探矿等领域有着广泛的应用。随着人们对闪烁晶体的更加深入的认识以及晶体生长技术的发展,许多已开发的闪烁晶体的性能得到优化和提高,应用范围也随之扩大,随着应用的更高要求,对闪烁晶体的综合性能要求越来越高,进一步设计、发现、开发和生长具有高密度、优良光学均匀性、高能束粒子阻止本领、高光产额、快衰减、高稳定性、低成本等综合优良性能的闪烁晶体仍然是闪烁材料研究的重点。简要综述了近年来卤化物、钨酸盐、锗(硅)酸盐、铝酸盐和硼(磷)酸盐等重要闪烁晶体材料的研究进展及其闪烁性能和应用前景。 相似文献
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总结了不同离子掺杂YAG晶体的生长、闪烁特性和Ce∶YAG晶体的发光机理。Yb∶YAG晶体具有非常短的衰减时间(0.98ns),但光产额只有约1190phot/MeV。Ce∶YAG晶体的衰减时间为88ns,光产额可达26000phot/MeV,它具有优良的综合性能,已应用于闪烁探测器和大规模集成电路检测。Gd或Gd/Ga等稀土离子与Ce共掺可进一步提高YAG晶体的闪烁性能,最高光产额达44000phot/MeV,衰减时间为56.9ns。 相似文献
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PbF2:Gd,Eu晶体X射线激发的发射光谱 总被引:1,自引:1,他引:0
用脱氧剂非真空环境下、Stockbarger方法生长未掺和掺钆和铕的、浓度范围在0.1 ̄0.2wt%的PbF2:β晶体。本文报导X射线激发PbF2:Gd晶体的Gd^3+发射。揭示了分别来自^6P和^6I多重态312.5和277.4nm发射带,而^6D→^8S发射被点阵再吸收。^6I的发射强度低于^6P,说明^6P能级优先占据。室温下以X射线激发在368.9和814.5nm之间观察到14条Eu^3+ 相似文献
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H. Kraus F.A. Danevich S. Henry V.V. Kobychev V.B. Mikhailik V.M. Mokina S.S. Nagorny O.G. Polischuk V.I. Tretyak 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2009,600(3):594-598
The scintillation properties of a zinc tungstate crystal, shaped as a hexagonal prism (height 40 mm, diagonal 40 mm) were determined. An energy resolution of 10.7% for the 662 keV γ-line of 137Cs was measured with the scintillator placed in a light collection setup similar to that used by the CRESST dark matter search. The light output and decay kinetics of ZnWO4 were examined over the temperature range 7–300 K and confirmed to be competitive with those of CaWO4. The radioactive contaminations of the ZnWO4 scintillator measured in the Solotvina Underground Laboratory do not exceed 0.1–10 mBq/kg (depending on radionuclide). Our study highlights the excellent feasibility of this ZnWO4 scintillator for a cryogenic dark matter experiment. 相似文献
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Novel methods for measuring afterglow in developmental scintillators for X-ray and neutron detection
C.M. Bartle A. EdgarL. Dixie C. VaroyR. Piltz S. BuchananK. Rutherford 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,651(1):105-109
In this paper we discuss two novel methods of measuring afterglow in scintillators. One method is designed for X-ray detection and the other for neutron detection applications. In the first method a commercial fan-beam scanner of basic design similar to those seen at airports is used to deliver a typically 12 ms long X-ray pulse to a scintillator by passing the test equipment through the scanner on the conveyor belt. In the second method the thermal neutron beam from a research reactor is incident on the scintillator. The beam is cut-off in about 1 ms using a 10B impregnated aluminum pneumatic shutter, and the afterglow is recorded on a dual range storage oscilloscope to capture both the steady state intensity and the weak decay. We describe these measurement methods and the results obtained for a range of developmental ceramic and glass scintillators, as well as some standard scintillators such as NaI(Tl), LiI(Eu) and the plastic scintillator NE102A. Preliminary modeling of the afterglow is presented. 相似文献
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R. Hoischen S. PietriD. Rudolph W. ProkopowiczH. Schaffner S. EmdeP. Golubev A. WendtN. Kurz H.J. WollersheimJ. Gerl 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,654(1):354-360
The design, R&D, and testing of a new plastic-scintillator detector for Time-of-Flight measurements with relativistic heavy-ion beams are presented. A design approach using 32 independent precise timing measurements of the same physical event is followed. This is different from the conventional scheme, which aims at two or four high-precision measurements. A circular, 27 cm in diameter, BC-420 plastic-scintillator sheet is read-out by 32 photomultiplier tubes in order to achieve an intrinsic detector resolution on the order of 10 ps root mean square. 相似文献
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A. K. Sinha 《Sadhana》2009,34(2):243-254
Heat load studies have been performed for the first crystal of a double crystal monochromator to be installed in a beamline
of the 2·5 GeV synchrotron radiation source Indus-2. Finite element analysis (FEA) has been used to calculate the temperature
distribution and the mechanical distortions on these crystals. Several cases of cooling schemes and heat loads have been studied.
Based on these FEA results, the analytical relationships available in the literature have been modified. It is shown that
modified analytical results compare well with the empirical results obtained from FEA. The optimisation of the cooling conditions
can be achieved by doing FEA calculations for only one case. All other cases can then be calculated by using analytical relations
proposed here. The proposed analytical equations are generic in nature and can be applied for any source—crystal combination
and therefore would be useful for performance prediction of any new monochromator on a new synchrotron source without taking
recourse to time consuming, computation-intensive FEA. 相似文献
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A novel two-dimensional circular photonic crystal (CPC) structure with a sectorial opening for shaping the beam of light sources was designed and investigated. When combined with light sources, the structure acts like an antenna emitting a directional beam which could be advantageously used in several nanophotonic applications. Using the two-dimensional finite-difference time-domain (2D FDTD) method, we examined the effects of geometrical parameters of the structure on the directional and transmission properties of emitted radiation. Further, we examined the transmitting and receiving properties of a pair of identical structures as a function of distance between them. 相似文献
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Masaru Kitamura Hideki Yoshikawa Takaho Tanaka Sei Fukushima 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2003,510(3):389-398
The quality of the YB66 crystal was investigated by rocking curve measurements using a conventional X-ray source and the synchrotron radiation of BL15XU at SPring-8 before and after the irradiation with synchrotron radiation. It is confirmed by evaluating the full-width at half-maximum of rocking curve and by the Lang topographic method that the YB66 crystal has a nonuniform quality and distribution of energy resolution, and that density of dislocations and subgrain boundary structures depended on the position of the crystal, as reported previously. A significant change in the quality of the YB66 crystal was not observed between before and after irradiation of synchrotron radiation. The qualities of single YB66 crystals are sufficiently good to maintain a high resolution for dispersing synchrotron radiation at power density and power of not more than 1.7 W/mm2 and 0.13 W, respectively, for about 1000 h at the third-generation light source SPring-8.
Furthermore, reactivity of YB66 crystal with GaIn was studied by SEM, EDX in the laboratory and by a transmission function of synchrotron radiation dispersed by a YB66 (4 0 0) double-crystal monochromator in the beam study of BL15XU. From these experiments, it is concluded that the reaction of YB66 crystal with GaIn does not occur. Thus, GaIn as an interface material between a YB66 crystal and a Cu holder coated with Ni is available for an indirect cooling system of BL15XU at SPring-8. 相似文献
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M. Ojaruega F.D. BecchettiA.N. Villano Hao JiangR.O. Torres-Isea J.J. KolataA. Roberts C.C. Lawrence 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,652(1):397-399
The response of large deuterated liquid scintillators (up to 10 cm diameter by 15 cm) to neutrons 0.5-20 MeV has been studied using the 2.5 MeV neutron generator at the University of Michigan, and the d(d,n), 13C(d,n), 27Al(d,n) and other reactions at the University of Notre Dame FN tandem accelerator. The latter utilize 9 and 16 MeV deuteron beams including a pulsed beam, which permitted time-of-flight measurements. Combining pulse-shape discrimination and time-of-flight allows gating on specific neutron energy groups to determine the detector response to specific neutron energies. This will permit accurate simulation of the detector response functions for applications of these detectors in nuclear research and homeland security applications. 相似文献
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光波在晶体表面来回反射形成了多种不同振幅的光波,光波叠加方式的不同会产生完全不同的效果.针对o光与e光非相干叠加和相干叠加两种情况,导出了光强公式.用铌酸锂晶体做了实验,结果与理论十分吻合.这对于分析晶体偏光干涉测量中的干扰以及充分利用干涉图信息改进测量方法与测量精度均具有重要意义. 相似文献
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Tissue-equivalent pure organic semiconducting crystals (OSCs) have unique advantages in direct X-ray detectors (DXDs), especially for biological tissue fluoroscopy, but their low carrier mobility and inherent weak absorption restrict the limit-of-detection (LoD) and sensitivity of DXDs. High-mobility OSCs theoretically facilitate charge collection and performance leaps, however, they are rare and suffer from poor solubility due to high conjugation, leading to nearly impossible crystal growth from solution and subsequent device applications. Here we report an ingenious solution-processed crystal-growth and high-performance DXD using 2,6-diphenylanthracene (2,6-DPA), a high-mobility OSC we developed recently. In contrast to previous OSCs, high-mobility 2,6-DPA exhibits low dark current density and large photoconductive gain, resulting in record-breaking LoD of <85 nGyair s−1 and sensitivity of >103 μC Gyair−1 cm−2. Compared with semiconductors containing high-Z atoms (Z is atomic number), the accuracy of 2,6-DPA based DXDs is not affected by near-edge absorption effects. Moreover, the non-linear relationship between irradiation current and dose rate is confirmed as a high injection effect. High mobility and ingenious crystal growth strategy make 2,6-DPA an ideal active material for DXDs and also provide the possibility for more optoelectronic applications. 相似文献