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South Dakota State University

Qi Hua Fan

Li Qin Zhou

Zhengrong Gu

Mukul Kumar Dubey

A method for using plasma to activate biochar is disclosed where reactive gas(es) are excited by external power; biochar set on a sample holder is electrically biased or set at a floating potential so that charged particles of a certain type are attracted to the biochar, leading to intensive chemical reactions.

Method for plasma activation of biochar material

The present invention discloses a novel rectangular sputtering magnetron cathode that significantly improves target utilization and sputtering efficiency. Different from conventional magnatron design that considers only magnetic field distribution and is, therefore, qualitive or empirical, the present magnetron cathode is developed through computer-aided simulation of plasma discharge. The magnetic and electric fields are optimized in a combined manner by quantitatively simulating electron trajectories, electron/Ar collisions, space charge distribution, and target erosion profile. Sputtering tests with Cu target show a target utilization of 55%&tilde;65%, much higher than conventional target utilization which is about 40%. Meanwhile, high sputtering efficiency is achieved by maintaining a relatively strong magnetic field over the surface of the target, which can be thicker than 12 mm, as a result of effective confinement of high-energy electrons.

Growing community of inventors

Ann Arbor, MI, United States of America

Qi Hua Fan