上海交通大学：《材料组织结构表征》课程教学资源（课件讲义）3. X射线衍射-X射线的发生器与防护

三、X射线的发生器与防护

三、X射线的发生器与防护

X射线的性质 ·X射线的本质 eU-hymax=hc/Xo ·X射线与物质的交互作用 ·X射线发生器 ·X射线的防护

X射线的性质 • X射线的本质 • X射线与物质的交互作用 • X射线发生器 • X射线的防护 eU=hvmax =hc/λ0

=1.24/0 X射线与物质的交互作用 =K(Z-a) 入kKa>x或KaA0 不相干散射 KaK2入KB 反冲电子 电子{ 俄歇电子 成分分析光电子 I连续谱=aiZU 光电效应 俄歇效应 I特征=Ai亿-Ux 荧光X射线K。>0 14 a(A) A

X射线与物质的交互作用 成分分析 XRD分析 吸收衬度成像 K >K> K K >K或K <<K 0  1.24 U I连续谱= α i Z U2   R I 特征  A i U  U K ( ) 1 2    K Z  3 3  m  K4  Z

X射线发生器 ·Sealed tube 。Rotating anode Synchrotron radiation

X射线发生器 • Sealed tube • Rotating anode • Synchrotron radiation

Cathode Sealed tube Line focus Coupling to a high voltage cable Point focus Anode Cathode Cathode projection X-rays X-rays Be window Anode Water Be windows Water in ·使用方便，功率低

Sealed tube • 使用方便，功率低

Rotating anode PF Rotating anode LF opoule PF Cathode projection Water in Water out, ·高功率， 制造维护困难

Rotating anode • 高功率，制造维护困难

Synchrotron radiation X-ray ·高亮(4~12x) beam ·准直性高（分辨率高） ·频谱宽 Storage ring Injection point weaq Bending Kusu lul magnet Wavelength,入 eg.上海光源

Synchrotron radiation • 高亮 (4~12x) • 准直性高(分辨率高) • 频谱宽 eg. 上海光源

Synchrotron radiation BUMo CAT

Synchrotron radiation

X射线的防护 当心电离辐射

X射线的防护

Radiation Ionizing Radiation and Non-Ionizing Radiation Ionizing radiation has sufficient Non-ionizing radiation does not energy to remove electrons from atoms. have the amount of energy needed to remove electrons from the atom. ·Visible light ·Radio waves C ·Alpha particles B ·Beta particles uununnuAu av Photons(gamma rays and x-rays) n ·Neutron particles 10m

Radiation Ionizing Radiation and Non-Ionizing Radiation Non-ionizing radiation does not have the amount of energy needed to remove electrons from the atom. Ionizing radiation has sufficient energy to remove electrons from atoms. • Visible light • Radio waves