共查询到20条相似文献,搜索用时 0 毫秒
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H. Y. Barminova 《Physics of Atomic Nuclei》2017,80(11):1665-1668
The possibility of using high-energy proton radiography for dense plasma diagnostics is discussed. The designed telescopic ion optical system for a proton radiography installation with a 1 GeV beam is presented. The schematic diagram of the proton microscope is given. It is shown that the estimate of spatial resolution for the installation obtained with consideration of chromatic aberrations of magnetic quadrupole lenses is limited from below. 相似文献
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用修正三梯度法测量强流脉冲束时间分辨发射度 总被引:2,自引:0,他引:2
三梯度法是加速器发射度测量的一种常用方法,但在低能强流的加速器上,由于空间电荷效应很显著,常规的三梯度方法不再适用.修正三梯度法是常规三梯度法考虑空间电荷效应后的改进,本文描述了修正三梯度法用于强流脉冲电子束发射度测量的理论依据,介绍了修正三梯度方法的实验方案.在35MeV,26kA,~100ns和18MeV,26kA,~100ns的两种强流脉冲电子束进行了发射度的实际测量.文中给出了在两种电子束上分别获得的实验结果和误差分析.实验结果表明,修正三梯度方法是强流脉冲电子束发射度测量的一种有效的手段. 相似文献
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Physics of Atomic Nuclei - A method for reconstruction of the volume density distribution in dynamic targets from their proton radiography image is considered. The reconstruction can be carried out... 相似文献
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A prototype of a laser driven proton accelerator is built at Peking University. Protons exceeding 10 MeV are accelerated from micrometer-thick aluminum targets irradiated by tightly focused laser pulse with 1.8 J energy and 30 fs duration. The beam energy spectrum and charge distribution are measured by a Thomson parabola spectrometer and radiochromic film stacks. The sensitivity of proton cut-off energy to the focusing of the laser beam, the pulse duration, and the foil thickness are systematically investigated in the experiments. Stable proton beams have been produced with an optimized parameter set, providing a cornerstone for the future applications of laser accelerated protons. 相似文献
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详细讨论了低能强流质子圆形加速器中质子穿越整数及半整数共振点的现象.通过对注入能量为1MeV,加速电压分别为1kV和2kV时的模拟计算,确定了束流安全穿越整数及半整数共振点对二极铁和四极铁加工误差的要求. 相似文献
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The Model study on the Resonant Phenomena in Low Energy Proton Circular Accelerators with Intense Beams 下载免费PDF全文
The phenomena that proton passes through the integer and half–integer resonance points in low energy proton circular accelerator with intense beams are discussed.The manufacturing tolerances of the dipole magnet and quadruple magnet is given through simulations on the cases when the injection energy is 1MeV and the accelerating RF voltage per one turn is 1kV and 2kV, respectively. With these given manufacturing tolerances, particles can safely cross over the integer and half–integer resonant points. 相似文献
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G. MieleO. Pisanti 《Nuclear Physics B - Proceedings Supplements》2011,217(1):149-151
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The range and straggling data obtained from the transport of ions in matter (TRIM) computer program were used to determine the trajectories of monoenergetic 60 MeV protons in muscle tissue by using the Monte Carlo technique. The appropriate profile for the shape of a proton pencil beam in proton therapy as well as the dose deposited in the tissue were computed. The good agreements between our results as compared with the corresponding experimental values are presented here to show the reliability of our Monte Carlo method. 相似文献
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Time-Resolved Fluorescent Imaging of Glucose 总被引:1,自引:1,他引:0
A method for the fluorescent imaging of glucose is described that is based on the detection of enzymatically produced hydrogen peroxide, using the europium(III) tetracycline complex as the fluorescent probe incorporated into a hydrophilic polymer layer. Coadsorption of glucose oxidase (GOx) makes these sensor layers respond to the hydrogen peroxide produced by the GOx-assisted oxidation of glucose. The hydrogel layers are integrated into a 96-microwell plate for a parallel and simultaneous detection of various samples. Glucose is visualized by means of time resolved luminescence lifetime imaging. Unlike in previous methods, the determination of H2O2 does not require the addition of peroxidase or a catalyst to form a fluorescent product. The lifetime-based images obtained are compared with conventional fluorescence intensity-based methods with respect to sensitivity and the dynamic range of the sensor layer. The main advantages provided by this sensing scheme for H2O2 include reversibility, applicability at neutral pH, and the straightforwardness of the transducer system and the imaging device. 相似文献
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Jaroslav Holoubek estmír Kok Petr tpnek 《Particle & Particle Systems Characterization》1999,16(3):102-105
We have successfully implemented a time-resolved small-angle light scattering apparatus with spatial averaging by means of conical lens or software processing. Averaging allows a significant reduction of measurement times and makes this technique suitable for the study of systems with very long times-scales, from 25 Hz to many hours. We report light scattering experiments on the dissolution of polymer blends and light reflection measurement from polymer composites as examples of applications. 相似文献
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时间分辨荧光免疫分析方法的光谱研究 总被引:6,自引:0,他引:6
时间分辨荧光免疫分析法是用三价稀土离子及其螯合剂作为示踪物 ,标记蛋白质、激素、抗体、核酸探针或生物活性细胞 ,待反应体系 (如 :抗原抗体免疫反应、生物素亲合反应、核酸探针杂交反应、靶细胞与效应细胞的杀伤反应等 )发生后 ,用时间分辨荧光技术测定反应体系中分析物的浓度 ,达到定量分析的目的。它之所以能够继放射性同位素标记、酶标记、化学发光、电化学发光后成为一种更新、更灵敏的检测方法 ,主要取决于它所用标记物三价稀土离子螯合物独一无二的物理及化学性质。主要报导了对使用的长寿命荧光团Eu3 螯合物的光谱研究结果 ,时间分辨技术及荧光增强技术的原理。实验表明 :选择 336~ 337nm的激发波长 ,有利于Eu3 的配位二酮体的激发及能量转移。 相似文献
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爆炸性物质太赫兹时间分辨光谱测量 总被引:6,自引:0,他引:6
利用自由空间电光取样方法,研究了四种炸药在太赫兹(THz)频段的光学特性。通过太赫兹时间分辨光谱测量,作者得到了四种炸药DNT(2,4-二硝基甲苯)、钝化的RDX(黑索今)、HMX(奥克托金)和TNT(2,4,6-三硝基甲苯)的透射光谱,进而计算得出它们在0.2~2.5 THz频段的吸收系数和折射率。作者发现,2,4-DNT在1.08 THz,HMX在1.82 THz存在显著的吸收尖峰,RDX在此频段存在多个吸收峰,TNT的吸收谱线相对其他三种样品比较平缓,这种共振吸收一般认为是由分子间相互作用或声子共振模式引起的。四种炸药对太赫兹波独特的吸收性质说明,太赫兹时间分辨光谱测量技术在炸药特征识别及安全检测领域具有潜在应用价值。作者对致癌物质偶氮苯进行了太赫兹光谱研究,发现了国产偶氮苯和进口偶氮苯在太赫兹波段均存在特征吸收峰,可用于物质鉴别。 相似文献
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时间分辨光学层析的实验研究 总被引:2,自引:1,他引:1
描述了一个基于Ti:Sapphire飞秒激光和同步扫描相机的时间分辨光层析(CT)实验系统。该系统采用步进电机驱动的三维移动平台对被测组织体作类似X射线层析工作方式的平行扫描,由此可获得多角度下的时间分辨投影,通过对三种代表不同吸收和散射特性组合的模拟组织体(phantom)进行实际测量,并应用相应的非线性迭代图像重建算法,获得了可靠的重建图像,研究结果表明,该系统构思简洁,工作可靠,是进行光层析成像技术研究的理想模式之一。 相似文献
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