Thin carbon foil resistance to differential pressure

Thin carbon foils are used in different environments for various purposes. For example, they are used in vacuum technology to create a barrier between two volumes, in space plasma instrumentation to detect the crossing of a particle passing through them, or as a stripper of electrons for high energy particles. In the case of a change of pressure on either side of the foil, the pressure differential creates mechanical stresses to the foil that can lead to irreversible damage. Few experiments have characterized the survivability of carbon foils as a function of pressure. In this study, we show measurements of the resistance to pressure of carbon foils (CF) up to partial rupture. The focus is on ultra-thin carbon foils (e.g., 0.5-1.0 μg/cm2) that are typically used in space plasma instrumentation. However, our results can be used in other areas of experimental physics. Our results show that the finer the pitch of the supporting grid, the more pressure resistant the foil is, indicating that the CF support grid is perhaps more important in the design trade than the foil thickness. For example, we find that nominal 1.0 μg/cm2 foils mounted on 13.1 lpmm (333 lines per inch) nickel grids can hold a remarkable static pressure of ∼9 kPa (∼1.3 psi) with almost no damage.