X-ray tube (p.48 in the textbook) 3 5 1一高压变压器2一灯丝变压器 3一X射线管 4一阳极5一阴极6一电子7一X射线
X-ray tube (p.48 in the textbook)
From continuous radiation to characteristic radiation 6 Mo Moseley's law: Ka B Characteristid λ= radiation (Z-0)2 25kV> Continuous radiation 3 网 20 2 15 First observed by 1 Barkla Sadler 10 SWL 5、 in1909 1.0 2.0 3.0 1.243 Wavelength(angstroms) 入mim V(kV) (nm)
From continuous radiation to characteristic radiation Mo First observed by Barkla & Sadler in 1909 Moseley's law: 𝜆 = 𝐵 (𝑍 − 𝜎) 2 𝜆𝑚𝑖𝑛 = 1.243 𝑉 (𝑘𝑉) (𝑛𝑚)
Characteristic and continuum (Bremsstrahlung)X-rays 75000 Characteristic CuKa Counts X-ray 50000 25000- CuL Continuum(Bremsstrahlung) X-ray CuKB 10 Energy (eV) 8
Characteristic and continuum (Bremsstrahlung) X-rays 8 Characteristic X-ray Continuum (Bremsstrahlung) X-ray
Features of characteristic X-rays Incident electron beam Ejected electron M shell White radiation (continuum) X-ray (characteristic radiation) Nucleus 9
Features of characteristic X-rays 9
Mechanism of characteristic radiation L3 Kp L2 LI M K K Nucleus Figure 2.3 Schematic illustration of characteristic X-ray radiation Cu: 入Ka1=0.15406nm 入Ka2=0.15444nm 入K6=0.13922nm KB九Ka
Cu: K< K Mechanism of characteristic radiation