SBIR-STTR Award

Removal of heat from the next generation of particle detection systems used in high energy physics experiments, under development by the Department of Energy, will present challenging thermal management and structural design issues. The most significant system design issue existent in the detectors which observe particle collisions, is that the detectors, their associated on-board electronics, support structure and cooling components place an undesirable amount of material in the path of the charge particles whose trajectories they are designed to measure. This project is to develop innovative, low-mass, stable composite structures with exceptionally good thermal conductivity which can be machined into complex shapes. An ultra lightweight integrated structure and cooling concept will be developed using advanced composite materials that are highly thermally conductive and have low physical interactions with the charged particles. The concept is ideally suited to addressing the needs of high energy physics detectors to be built at the Large Hadron Collider at CERN. The goal of Phase I is to evaluate an innovative leak-tight, carbon-carbon structure concept that would serve to cool and support thin, delicate pixel and silicon strip detectors. The structure will be highly stable, possess an exceptionally high thermal conductivity, as well as be adaptable to complex shapes to satisfy the detector applications. An important aspect will be to demonstrate electrical compatibility with detector performance. Phase II will be concerned with advancing the integration of cooling and support structure system for an entire pixel detector. Major elements of a pixel detector will be constructed, and comprehensive thermal and stability tests would be conducted.Commercial Applications and other Benefits as described by the awardee:Advancements in ultra-lightweight composite cooling structures will find application in space programs in which DOE has a key interest, like the Gamma-Ray Large Aperture Space Telescope (GLAST). Commercial applications may be found in the computer applications requiring heat removal in confined spaces.

Although the charged-particle tracking devices that are under development for experiments at the Large Hadron Collider (LHC) at CERN will achieve high precision through the use of silicon detectors, they still require design innovations and a unique choice of materials to achieve stringent experimental goals. To accomplish these goals, structure and cooling concepts must be combined to effect a highly stable platform for supporting the delicate detector modules. This project will integrate the cooling and structural aspects for a pixel detector that employs the distinct advantages of carbon-carbon materials in an ultra-lightweight, stable dector design. The carbon-carbon materials can be tailored to achieve a thermal conductivity significantly higher than aluminum, yet with a coefficient of thermal expansion low enough to ensure high dimensional stability. In addition, the materials are radiation-hard and would be unaffected by the intense radiation field found in the LHC. In Phase I, cooling structures for a pixel detector sector were constructed and tested in a simulated environment of -15 °C. Ultra-lightweight carbon-carbon tubes were fabricated and sealed with a glassy-carbon coating as well as with resin. The tubes were sandwiched between structural facings in which the heat dissipation, 6000 W/m5, simulated the module electronics. Heat was removed with < 5 °C overall temperature gradient between the module mounting surface and the coolant. Phase II will complete the development and stability testing of the sandwich structures, develop a means for achieving electrical isolation of the modules, and develop a production capability for the LHC.

Commercial Applications and Other Benefits as described by the awardee:
These devices should find application in high energy physics detectors like ATLAS and CMS, where radiation-hard, ultra-lightweight stable systems are required. They should also find use in space-based tracking experiments, e.g., NASA=s Gamma-ray Large Aperture Space Telescope (GLAST), where lightweight, passively cooled stable structures are needed