The double-slit experiment with carbon-60 molecules, also known as the "Buckyball experiment," involves passing a beam of carbon-60 molecules (C60) through a double-slit apparatus to observe their interference pattern. Here's an overview of how the molecular beam is typically generated:
Source of Carbon-60 Molecules: Carbon-60 molecules, or buckyballs, are typically obtained through a process called "evaporation." Initially, a solid form of carbon-60 is prepared, such as a carbon-60 powder or a crystal. This solid is then heated to a temperature where the carbon-60 molecules vaporize, forming a gas phase.
Molecular Beam Formation: To create a directed molecular beam, the vaporized carbon-60 molecules need to be collimated and accelerated. This is usually achieved using a combination of techniques, including supersonic expansion and differential pumping:
a. Supersonic Expansion: The vaporized carbon-60 gas is passed through a small nozzle or orifice into a region of lower pressure. This causes the gas to expand rapidly, forming a supersonic jet. The expansion cools down the gas and increases the velocity of the molecules, leading to the formation of a well-collimated molecular beam.
b. Differential Pumping: In order to maintain a high vacuum in the experimental region, a differential pumping system is employed. This system consists of a series of chambers with varying pressure levels. The supersonic molecular beam is introduced into a chamber at a higher pressure, and then subsequent chambers are pumped to lower pressures. This differential pumping setup helps to maintain the molecular beam's quality and prevent collisions with residual gas molecules.
Beam Alignment: The molecular beam is then directed towards the double-slit apparatus, which consists of two narrow slits separated by a small distance. The alignment of the beam with respect to the slits is crucial to achieve the desired interference pattern. Precise positioning and alignment techniques are employed to ensure that the molecular beam passes through the slits accurately.
Detection and Interference Pattern: Beyond the double slits, there is a screen or detector placed to capture the molecular beam after it passes through the slits. The pattern observed on the detector is the result of the interference between the different paths the carbon-60 molecules can take as they pass through the two slits. The interference pattern emerges due to the wave-particle duality of matter, where the carbon-60 molecules exhibit both particle-like and wave-like behavior.
It's worth noting that the specific experimental setup for the double-slit experiment with carbon-60 molecules may vary depending on the details of the experiment and the equipment used. Researchers continually refine and adapt these techniques to investigate the quantum behavior of larger and more complex molecules.