BTECH PHYSICS | DAVISSON GERMER EXPERIMENT |APPLIED PHYSICS|DUAL NATURE of Radiation Telugu #btech

A crucial observation was made at an accelerating voltage of 54 volts, where a maximum electron intensity was recorded at a scattering angle of 50 degrees. This finding is represented graphically, showing the intensity of electrons relative to the scattering angle.

The Davisson-Germer experiment, conducted in 1927, is a pivotal topic in physics. It aimed to prove D. Broglie's 1924 theoretical statement that particles possess wave-like properties, similar to how light exhibits wave nature. De Broglie initially proposed that every moving particle has a wave nature, but this was a purely theoretical statement.

The Davisson-Germer experiment in 1927 provided practical proof for de Broglie's theoretical work. This led to de Broglie receiving the Nobel Prize in 1929 for his theoretical contributions, and Davisson and Germer were awarded the Nobel Prize in 1937, ten years after their successful experimental verification.

The experimental setup includes a filament, a low tension battery (B1) for heating, a high tension battery for accelerating electrons, a cylindrical path, a nickel crystal target, and a movable collector with a galvanometer. The filament, when heated, emits electrons, which are then accelerated towards the nickel crystal.

Using Bragg's equation, nλ = 2d sinθ, practical and theoretical wavelengths were calculated. For the Davisson-Germer experiment, 'n' (order of maxima) is 1, 'd' (distance between atomic layers in the nickel crystal) is 0.91 Å, and 'θ' (angle between incident ray and atomic layer) is calculated to be 65 degrees from the 50-degree scattering angle. Substituting these values gives a practical wavelength of 1.65 Å.

De Broglie's theoretical wavelength is calculated using the formula λ = 12.27 / √V, where V is the accelerating voltage (54V). This yields a theoretical wavelength of 1.67 Å. The close resemblance between the practical (1.65 Å) and theoretical (1.67 Å) values confirmed de Broglie's hypothesis of the wave nature of particles.

The procedure involves heating a filament with a low-tension battery to release electrons. These released electrons are then accelerated by a high-tension battery and directed through a narrow cylindrical path to hit a nickel crystal target. The electrons scatter off the crystal and are collected by a movable collector, with their deflection measured by a galvanometer. The accelerating voltage is varied from 44 to 68 volts.