Massachusetts Institute of Technology

Other

Donna L Smatlak

Daniel R Cohn

Barton G Lane, Iii

Leslie Bromberg

Jeffrey E Surma

Charles H Titus

Paul P Woskov

J Kenneth Wittle

Herbert H Sawin

William C Guss

Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury.

Continuous, real time microwave plasma element sensor

A method and apparatus for the pyrolytic destruction or synthesis of gases via a highly tunable combination of radio frequency heating and electron beam irradiation is disclosed. The method is appropriate for destroying toxic gases emanating from hazardous wastes and for synthesizing new molecules from the molecules of a gas. The method is also appropriate for creating scavenger gases and hot gases with large enthalpy for use in sterilization procedures, for example. Embodiments are disclosed employing inductive or direct waveguide/cavity coupling of radio frequency power to the gas. In embodiments of the invention, magnetic fields are used to modify the paths of the electrons in the beam to facilitate tuning and improve the energy efficiency of the system. In a two-stage system, solid and/or liquid wastes are first heated in order to vaporize the toxic materials. Then, the gases produced in the first stage are destroyed by the combination of radio frequency heating and electron beam irradiation of the invention.

Tunable plasma method and apparatus using radio frequency heating and

A toroidal ECR reactor is described in which a poloidal magnetic field is established in a plasma generating chamber in which a specimen to be processed is disposed on an electrode in a specimen chamber. Microwaves and gaseous reactants are introduced into the plasma generating chamber. A plasma discharge occurs in which high energy electrons are confined in a plasma source region extending between a magnetic mirror formed in the specimen chamber out of line-of-sight to the wafer(s) when disposed on the electrode. A baffle region formed between the two chambers prevents microwaves from entering the specimen chamber. The reactor is particularly suitable for etching or depositing films on semiconductor substrates, since the sensitive substrates are not exposed to the high energy ions and/or photons of the source region.

Toroidal electron cyclotron resonance reactor

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Arlington, MA, United States of America

Donna L Smatlak