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微通道板光子计数成像探测器预处理实验研究 总被引:4,自引:2,他引:2
微通道板光子计数成像探测器是嫦娥三号极紫外相机的关键成像器件,嫦娥三号极紫外相机被用于探测地球等离子层中极微弱的He+共振散射辐射,为了消除微通道板内部吸附的残余气体产生的离子反馈等背景噪音对探测器微弱信号成像性能的影响,需要对微通道板进行预处理.预处理包括高温真空烘烤和紫外光电子清刷.根据预处理的实验要求,设计了一套微通道板预处理装置,为微通道板预处理实验提供高真空环境和高温加热及保温功能.本文详细介绍了微通道板预处理实验的实现过程,对三片Z型级联的微通道板进行预处理实验后,背景噪音由27.09counts/s·cm2降低为0.53counts/s·cm2、空间分辨率达到125μm,上述实验结果表明MCP在预处理之后其表面、亚表面和体内吸附的杂质气体得以有效去除,获得了稳定的增益,成像性能也得以改善. 相似文献
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极紫外波段微通道板光子计数探测器 总被引:2,自引:0,他引:2
研究了一种极紫外波段微通道板(MCP)光子计数探测器,用于探测地球等离子体层中极微弱的30.4 nm辐射。通过改变电压、温度等参数对比了该微通道板光子计数探测器的暗噪声和分辨率的变化。结果表明:微通道板探测器的暗噪声主要来源于残余气体离子反馈和热噪声,因此要降低探测器暗噪声,应对微通道进行彻底的预处理除气,并尽量避免探测器在高温状态下工作,常温下经过预处理的微通道板光子探测系统的暗计数率仅为0.34 count/(s.cm2)。系统的分辨率主要受电压和计数率的影响,受温度影响不明显。由于不同的微通道板有不同的耐压范围,过小或过大的电压或计数率都会造成系统分辨率的降低。 相似文献
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基于CE-3极紫外(EUV)相机最高工作温度为70 ℃的要求,对EUV相机的微通道板(MCP)位置灵敏阳极光子计数成像探测器实验件在70 ℃时的性能进行了研究,该探测器主要由工作在脉冲计数模式下的MCP堆、楔条形感应电荷阳极及相关的模拟和数据处理电路组成。为了获得稳定的MCP堆电子增益及较小的暗计数率,对MCP堆进行了预处理,包括380 ℃条件下真空高温烘烤18 h,以及电子清刷100 μA·h,并测量了预处理前后暗计数率;测量了探测器工作在室温和70 ℃时的暗计数率、空间分辨率、增益,测量结果表明探测器的空间分辨率为5.66 lp/mm,与室温下空间分辨率相同,暗计数率虽然小于1 counts/(s·cm2),但70 ℃暗计数率是室温的2~5倍;对探测器的使用寿命进行了初步分析。实验结果和分析表明探测器在空间分辨率、暗计数率、使用寿命等方面均满足EUV相机的要求。 相似文献
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GEM探测器是一种新型微型气体探测器(Micro-Pattern Gas Detector), 在粒子物理实验及低能X射线成像系统中有着较大的应用前景. 文章研制了一种适用于低能X射线成像和带电粒子径迹测量的三级GEM气体探测器. 使用放射源55Fe对其气体放大特性、电荷传输效率及能量分辨本领等性能进行了实验研究, 重点研究了传输区电场对气体有效增益和能量分辨本领的影响. 实验结果表明, 三级GEM探测器的暗电流和噪声较小, 有效增益能够达到105以上并稳定地工作, 对5.9keV的X射线能量分辨率可达24%, 传输区电场强度大于3000V/(cm.atm)时, 能量分辨率基本稳定在30%左右. 相似文献
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室温下首先采用160keVHe离子注入单晶Si样品到剂量5×1016ions/cm2,部分样品再接受80keVSi离子辐照到较高的剂量5×1015ions/cm2或接受高密度H等离子体处理.应用透射电镜观测分析了800℃高温退火引起的空腔的形成形貌.结果表明,附加Si离子辐照或H等离子体处理会影响Si中空腔的生长.就Si离子附加辐照而言,由于辐照引入富余的间隙子型缺陷,因此,它会抑制空腔的生长,而高密度H等离子体处理则有助于空腔的生长.定性地讨论了实验结果. 相似文献
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An experimental setup for studying optical materials under the action of plasma-emitted intense (up to 105 W/cm2) ultraviolet and vacuum ultraviolet radiation is described, and methods for estimating the radiation damage are developed. The damage produced in calcium fluoride ionic crystals at ~300 K by low (103 rad) and moderate (106 rad) absorbed doses is experimentally estimated. 相似文献
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The absolute intensity of a vacuum sliding spark (length 2–10 cm, half cycle 0,8 μsec) has been measured in the spectral region between 0,4 and 3μ. From the long wavelength radiation emitted from an optically thick layer, one gets the temperature, from the short wavelength radiation emitted from an optically thin layer, one obtains the density. Using polyethylene as an insulator we reached a temperature of 4·105 °K at electron densities of 8·1018 cm?3 and current densities of 1.2·106 A/cm2. The temporal development of temperature and density has been determined. The maximum intensity at λ=0.43 μ was found to be 5·104 (7·1010 W/cm3 ster) as large as that of the positive crater of a properly driven carbon arc. At λ=3 μ this same parameter turned out to be 300 times as large (5·107 W/cm3 ster). 相似文献
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Yu. V. Korobkin V. B. Rozanov A. S. Shikanov G. A. Vergunova 《Journal of Russian Laser Research》1998,19(2):134-152
The results of study of frequency-tuned monochromatic x-ray source are reported. The source was developed on the basis of a vacuum diode with a laser-plasma cathode. The source proposed is particularly promising, if the range of x-ray energy higher than 5 keV is of interest. The source features a spectral brightness higher than 1019 photons/(cm2·s·sr·keV) and an x-ray pulse duration no larger than 10?8 s. An electromagnetic model of such a cathode is proposed and evaluated in order to assess the feasibility of an x-ray source with a laser-plasma cathode of higher performance. The possibility of using a ferroelectric electron emitter is discussed. 相似文献
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Hans Conrads 《Zeitschrift für Physik A Hadrons and Nuclei》1967,200(4):444-455
A lithium plasma is produced by discharging a 40 kV, 0,3 μF capacitor through a lithium-hydride-capillary (diameter 2 mm, length 20 mm) in vacuum (p~10?4 Torr). During the first half-cycle (0,6 μs) Bremsstrahlung of Li III is observed in the visible and infrared, and the Lyman series of Li III together with the recombination continuum in the vacuum UV (100 Å). The high members of the Lyman series are broadened by Stark effect giving an electron density of about 6 · 1018 cm?3. In the infrared the radiation is emitted from an optically thick plasma at a time when the free-free continuum in the visible is emitted from an optically thin plasma. Temporal development of electron temperatureT e and electron density Ne has been measured from the absolute intensity in these spectral regions. Typical values ofT e=230 000° K andN e 5 · 1018 cm?3 e.g. have been obtained. For these values the relaxation time for an ionisation equilibrium is short compared to the observation time. The complete ionisation of Li III has been checked by absorption measurements near 100 A. Thus the absolute intensity of the recombination continuum could be calculated. An experimental arrangement was built to measure simultaneously the time history of the intensity in the vacuum ultraviolet, in the visible, and infrared spectral regions. 相似文献
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用金属蒸汽真空弧源,以40kV加速电压对纯锆样品分别进行了1016—1017/cm2的钇、镧离子注入,注入温度约为130℃.然后对注入样品进行表面分析.x射线光电子能谱分析表明,注入的钇以Y2O3形式存在,镧以La2O3形式存在.俄歇电子能谱表明,纯锆基体表面的氧化膜厚度随着离子注入剂量的增加而增加,当离子注入剂量达到1017/cm2时,氧化膜的厚度达到了最大值.卢瑟福背散射显示镧层的厚度约为30nm,同时直接观察到当离子注入剂量为(La+Y)1017/cm2时,纯锆样品表面发生了严重的溅射.
关键词:
纯锆
钇和镧离子共注入
卢瑟福背散射
x射线光电子能谱 相似文献
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Michal Novotn?? P??emysl Fitl Anna Krasilnikova Sytchkova Ji???- Bul?-?? Jan Lanaok Petr Pokorna David Najdek Jia Boan 《Central European Journal of Physics》2009,7(2):327-331
The effect of pulsed laser treatment of metal, and metal blacks, was studied. Gold and black gold thin films were fabricated
by thermal evaporation of gold in a vacuum and nitrogen atmosphere respectively. Black gold films were grown in a nitrogen
atmosphere at pressures of 200 Pa and 300 Pa. UV pulsed laser radiation (λ = 266 nm, τ = 4 ns), with fluence ranging from 1 mJ·cm−2 to 250 mJ·cm−2 was used for the film treatment in a vacuum and nitrogen atmosphere. The nitrogen pressure was varied up to 100 kPa. Surface
structure modifications were analyzed by optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy
(SEM). Energy dispersive X-ray spectroscopy (EDX) was used for chemical characterization of the samples. A significant dependence
of the film optical and structural properties on laser treatment conditions (laser fluence, ambient pressure and number of
applied pulses) was found. The threshold for observable damage and initiation of changes of morphology for gold and black
gold surfaces was determined. Distinct modifications were observed for fluences greater than 106 mJ·cm−2 and 3.5 mJ·cm−2 for the gold and black gold films respectively. Absorbtivity of the black gold film is found to decrease with an increase
in the number of laser pulses. Microstructural and nanostructural modifications after laser treatment of the black gold film
were observed. EDX analysis revealed that no impurities were introduced into the samples during both the deposition and laser
treatment.
相似文献
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T. V. Kazachevskaya S. I. Avdyushin D. A. Gonyukh A. I. Lomovsky A. A. Nusinov P. M. Svidsky Yu. N. Tsygelnitsky V. N. Oraevsky I. M. Kopaev S. I. Boldyrev E. D. Mishchenko 《Radiophysics and Quantum Electronics》1996,39(11-12):1011-1014
Data on the equipment mounted on board the KORONAS-I satellite and solar flux measurements in the extreme ultraviolet range (λ<130 nm) are presented. A thermoluminescent technique was used for solar ultraviolet radiometry (SUR). Vacuum ultraviolet solar spectrometry (VUSS) equipment based on the gas-photoelectron spectrometry method was employed to measure the He II 30.4 nm line in the solar spectrum. The solar flux in the region λ <130 nm was 7.5 erg·cm?2s?1 and the Lyman alpha line intensity was (3.3–3.7) · 1011 quant·cm?2s?1 in the low solar activity period from March to June 1994. The intensity of the He II (30.4 nm) line was varied in the limits of (6.0–7.5)·109 quant·cm?2s?1 from the 4 th to the 7 th of March, 1994. No intensive solar flares were registered in the observation period. An increase in the solar flux by ~15% was observed at λ <130 nm during the B4.5 X-ray flare (June 30, 1994, 01 h 08 m UT). 相似文献
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An experimental arrangement is described which allows the detection of low gas densities by resonance fluorescence in the
vacuum ultraviolet. As a light source a capillary discharge through helium was used. Fluorescence signals as a function of
density have been measured in krypton, deuterium, and hydrogen, and the results have been compared with calculations. Detection
limits of 3·109 atoms/cm3 have been obtained. 相似文献