Improved carbon micro-ribbon targets and stripper foils for the IUCF cooler ring

Abstract

Carbon micro-ribbons have been made which are stronger and a factor of three thinner than any previously made at IUCF. Ribbons of 4.2 μg/cm 2 thickness and 3.3 μm width were mounted to span 22-mm lengths. Also, open-edged (32-mm) stripper foils of 4-μg/cm 2 carbon have been prepared with significantly reduced curling at the open edge. For both the foils and ribbons, the progress is the result of efforts to produce uniform, densely distributed microscopically-sized features on the surface of glass substrates. Along with the grinding technique currently used to texture the substrates, a heat treatment method which improves the electrical conductivity of carbon micro-ribbons, and a method to make wire-grill evaporation masks with more closely regulated spacing of the wires is described. Also, initial experience depositing ultra-thin layers of several desired Cooler target materials onto the micro-ribbons is reported briefly. Carbon micro-ribbons are thought to have considerable potential as backings for Cooler targets.