The United States of America As Represented by the Administrator of the

The United States of America As Represented by the Administrator

Ben T Ebihara

Ralph Forman

Jeffrey I Eldridge

The apparatus disclosed in the present invention measures the force at which a fiber resist the motion of an indenter driven at constant speed. This apparatus conducts these test in a vacuum of about 10.sup.-6 tort and at temperatures up to 1100.degree. C. Temperature and vacuum environment are maintained while controlling indenter motion, sample position, and providing magnified visual inspection during the test.

Apparatus for performing high-temperature fiber push-out testing

A field emission cathode 12 is positioned in a pair of intersecting cross grooves 30, 32 in the end of a ceramic tube 14 by a metal end cap 24. A spring 34 in electrical contact with the base of the cathode provides the necessary pressure to maintain continuous circumferential electrical contact between the gate film and a raised edge 38 on the end cap. With this structure the cathode chip is self-centering and easily replaceable. Also the gate film of the cathode is not abraded or rubbed during installation, and the holder is readily degassed.

Apparatus for mounting a field emission cathode

It is an object of the invention to provide a spent particle collector which will maintain its structural integrity when raised to a high temperature although constructed of materials having widely different coefficients of expansion. The collector is comprised of one or more axisymmetric stages, each stage comprising a subassembly. A subassembly includes an inner pyrolytic graphite ring, a transition ring, a ceramic insulator ring and an outer metal ring which forms part of the wall of the collector. Each transition ring is of a ductile metal having high thermal conductivity and is provided with an annular sputter shield wall extending toward the source of spent particles and, where necessary, a trough in the other surface to enclose the sputter shield of the next adjacent transition ring. A plurality of radial extending slots are provided in a transition ring to form segments which are retained in their position by the sputter shield. This arrangement with the ceramic ring outwardly of the transition ring keeps the latter in contact with the inner pyrolytic graphite ring.

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Strongsville, OH, United States of America

Ben T Ebihara