A researcher wishes to study quantum interference effects in a beam of neutral helium…

PHYSICS · Multi-part · CBSE · Physics · Dual Nature of Radiation and Matter · Dual Nature of Radiation and Matter

Problem

A researcher wishes to study quantum interference effects in a beam of neutral helium atoms (mass 6.6×10−27 kg6.6\times10^{-27}\,\text{kg}). For the planned apparatus the interference pattern is observable only if the atoms have a wavelength of at least 0.050 nm0.050\,\text{nm}. Use h=6.63×10−34 J sh = 6.63\times10^{-34}\,\text{J\,s}. (a) Determine the speed each helium atom must have so that its wavelength meets the 0.050 nm0.050\,\text{nm} criterion. (b) At room temperature (300 K300\,\text{K}) helium atoms in a gas typically have an rms speed of about 1.25×103 m s−11.25\times10^{3}\,\text{m\,s}^{-1}. Compare this thermal speed with the speed found in part (a) and discuss briefly whether additional cooling of the gas would be required to observe interference in the apparatus.

Related theory

Browse the problem library