Abstract: A macroboule is disclosed, formed of a bundle of hollow channel elements of fusible material and of different internal diameters. They are arranged with the elements of smallest diameter positioned in the center of the bundle and those of largest internal diameter constituting the outer row of the bundle with uniform or step by step graduation between these extremes. The macroboule is useful for forming a channel multiplier.

Abstract: 1. A process for forming a multiple-channel micro-tubular device comprising the following steps:Assembling a plurality of individual tubes of heat deformable material into a closely packed array of a predetermined cross section;Applying heat to said array to fuse said tubes into a unitary honeycomb structure;Drawing said heated structure to reduce its cross section by at least an order of magnitude;Cutting the drawn honeycomb structure into segments of a predetermined length and entrapping gas in each of the component tubes of said segments at a predetermined temperature below the fusion temperature of said material;Packing a plurality of said segments together to form a cluster;And heating said cluster to a temperature above said predetermined temperature to fuse them into a unitary structure without collapsing said tubes.