Atomic and Nuclear Physics - Electron Diffraction

De Broglie's hypothesis suggests that particles have wave properties in addition to their classical particle properties.

Determining the wavelength of electrons allows for the verification of de Broglie's equation and deepens the understanding of wave-particle duality.

The technique used is Debye-Scherrer diffraction, which involves the diffraction of electrons in a polycrystalline lattice.

<p>Lattice plane spacings can be determined by analyzing the diffraction patterns produced when electrons are scattered by the atomic planes in graphite.</p> Signup and view all the answers

<p>Wave-particle duality is crucial for explaining phenomena at the atomic level, as it helps describe how particles can exhibit both wave-like and particle-like behaviors.</p> Signup and view all the answers

<p>5 keV</p> Signup and view all the answers

<p>To supply the electron diffraction tube with power for cathode heating.</p> Signup and view all the answers

<p>It must not be exposed to mechanical stress.</p> Signup and view all the answers

<p>X: focusing electrode</p> Signup and view all the answers

<p>They should be treated with care and not bent.</p> Signup and view all the answers

<p>Max. 2 mA.</p> Signup and view all the answers

<p>Danger of implosion.</p> Signup and view all the answers

<p>It should be mounted in the tube stand.</p> Signup and view all the answers

<p>Huygens’ principle states that every point on a wave front can be considered as a source of secondary wavelets that superpose to create the new wave front.</p> Signup and view all the answers

<p>The Bragg condition is significant because it indicates that constructive interference occurs when the path differences of reflected rays are integer multiples of the wavelength, allowing for clear diffraction patterns.</p> Signup and view all the answers

<p>In this model, the wavelength λ remains unchanged with respect to the incident wave front.</p> Signup and view all the answers

<p>The concentric circles indicate the reflections produced by numerous crystallites where the Bragg condition is satisfied for a given direction of incidence and wavelength.</p> Signup and view all the answers

<p>In the Bragg condition, 'd' represents the lattice plane spacing, and ϑ is the diffraction angle, which is defined by the relationship $2d imes ext{sin} heta = n imes ext{λ}$.</p> Signup and view all the answers

<p>The lattice plane spacings are given as $d_1 = 2.13 imes 10^{-10}$ m and $d_2 = 1.23 imes 10^{-10}$ m.</p> Signup and view all the answers

<p>The 'glancing angle' refers to the diffraction angle ϑ associated with the reflections satisfying the Bragg condition.</p> Signup and view all the answers

<p>The formula implies that the tangent of twice the diffraction angle is proportional to the diameter D of the rings and inversely proportional to twice the distance L between the graphite and the screen.</p> Signup and view all the answers

<p>The maximum accelerating voltage U that can be applied is 5 kV.</p> Signup and view all the answers

<p>The direction of the electron beam can be influenced by using a magnet clamped on the neck of the tube.</p> Signup and view all the answers

<p>If two diffraction rings cannot be seen perfectly, it may be necessary to adjust the magnet to illuminate another spot of the sample.</p> Signup and view all the answers

<p>The diameters D1 and D2 of the diffraction rings are measured to analyze the diffraction pattern and determine the wavelengths.</p> Signup and view all the answers

<p>The range of accelerating voltage U used in the experiment is from 3 kV to 5 kV, in steps of 0.5 kV.</p> Signup and view all the answers

<p>In addition to the diameters, the distance between the graphite foil and the screen should be measured.</p> Signup and view all the answers

<p>The measured diameters and accelerating voltages allow for the determination of the wavelengths λ1 and λ1, theory.</p> Signup and view all the answers

<p>Varying the accelerating voltage affects the size and symmetry of the diffraction rings observed.</p> Signup and view all the answers

<p>The diameter D of the diffraction rings is proportional to the square root of the accelerating voltage U.</p> Signup and view all the answers

<p>The variable L represents the distance between the graphite foil and the screen, which is 13.5 cm.</p> Signup and view all the answers

<p>Lattice plane spacings d1 and d2 can be determined by measuring the diameters D1 and D2 of the concentric rings as a function of the accelerating voltage U.</p> Signup and view all the answers

<p>When operating above 5 kV, X-rays are generated, which require precautions to avoid exposure.</p> Signup and view all the answers

<p>The formula is D = k * √U, where k is a constant dependent on other parameters.</p> Signup and view all the answers

<p>The variable k is a constant that incorporates factors such as L, h, d, m, and e, influencing the scaling of diameters.</p> Signup and view all the answers

<p>The cathode heating sockets F1 and F2, the cathode cap C, the focusing electrode X, and the anode A must be connected.</p> Signup and view all the answers

<p>The anode should be connected to a positive pole of 5 kV/2 mA output.</p> Signup and view all the answers

<p>The formula used is given as equation (VIII).</p> Signup and view all the answers

<p>The average diameters D1 and D2 are determined by taking five measurements each.</p> Signup and view all the answers

<p>The constants provided are e = $1.6021 imes 10^{-19}$ C, m = $9.1091 imes 10^{-31}$ kg, and h = $6.6256 imes 10^{-34}$ J⋅s.</p> Signup and view all the answers

<p>The distance L = 13.5 cm is crucial as it serves as a reference point for analyzing the diffraction pattern.</p> Signup and view all the answers

<p>The measured diameters D1 and D2 vary as a function of the accelerating voltage U, influencing the diffraction pattern.</p> Signup and view all the answers

<p>The symbols λ1,theory and λ2,theory represent the theoretically calculated wavelengths of electrons.</p> Signup and view all the answers

<p>Averaging five measurements minimizes errors and provides a more accurate estimation of diameters D1 and D2.</p> Signup and view all the answers

<p>Equations (IV) and (VIII) are primarily used to calculate the diameters of the diffraction rings.</p> Signup and view all the answers