Sandia National Laboratories

Douglas A Chinn

Arnold Burger

Ralph B James

Gomez W Wright

David J Irvin

F Patrick Doty

A &#x3c0;-conjugated organic material for detecting ionizing radiation, and particularly for detecting low energy fission neutrons. The &#x3c0;-conjugated materials comprise a class of organic materials whose members are intrinsic semiconducting materials. Included in this class are &#x3c0;-conjugated polymers, polyaromatic hydrocarbon molecules, and quinolates. Because of their high resistivities (&#x2267;10ohm&#xb7;cm), these &#x3c0;-conjugated organic materials exhibit very low leakage currents. A device for detecting and measuring ionizing radiation can be made by applying an electric field to a layer of the &#x3c0;-conjugated polymer material to measure electron/hole pair formation. A layer of the &#x3c0;-conjugated polymer material can be made by conventional polymer fabrication methods and can be cast into sheets capable of covering large areas. These sheets of polymer radiation detector material can be deposited between flexible electrodes and rolled up to form a radiation detector occupying a small volume but having a large surface area. The semiconducting polymer material can be easily fabricated in layers about 10 &#x3bc;m to 100 &#x3bc;m thick. These thin polymer layers and their associated electrodes can be stacked to form unique multi-layer detector arrangements that occupy small volume.

Organic materials and devices for detecting ionizing radiation

A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/o NHF and 10 w/o HOin water.

Surface treatment and protection method for cadmium zinc telluride crystals

A valve actuator based on a conductive polymer gel is disclosed. A nonconductive housing is provided having two separate chambers separated by a porous frit. The conductive polymer is held in one chamber and an electrolyte solution, used as a source of charged ions, is held in the second chamber. The ends of the housing a sealed with a flexible elastomer. The polymer gel is further provide with electrodes with which to apply an electrical potential across the gel in order to initiate an oxidation reaction which in turn drives anions across the porous frit and into the polymer gel, swelling the volume of the gel and simultaneously contracting the volume of the electrolyte solution. Because the two end chambers are sealed the flexible elastomer expands or contracts with the chamber volume change. By manipulating the potential across the gel the motion of the elastomer can be controlled to act as a &ldquo;gate&rdquo; to open or close a fluid channel and thereby control flow through that channel.

Actuator device utilizing a conductive polymer gel

A CdZnTe (CZT) crystal provided with a native CdO dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals is disclosed. A two step process is provided for forming the dielectric coating which includes etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and passivating the CZT crystal surface with a solution of 10 w/o NH F and 10 w/o H O in water after attaching electrical contacts to the crystal surface.

Ionizing radiation detector

A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/o NH F and 10 w/o H O in water.

Growing community of inventors

Livermore, CA, United States of America

Douglas A Chinn