Ultra-Lightweight Carbon Foam for Future Collider Tracking Detectors

Lowmass, ultrastable particle tracking detectors will be critical elements of upgrades to experiments at the Large Hadron Collider (CERN) and at potential future electronpositron colliders. Mass assigned to support structures, although critical in function, compromises detection through production of secondary particles that interferes with particle tracking. This SBIR focuses on lowering the mass associated with sandwich core materials being used in detector support structures, by a factor of 5 or more. This will require new, innovative, and entirely different foam processing. The method proposed will lead to a hollow foam ligament, with ligament shell material composed solely of high conductivity graphite. Accomplishing this advancement in foam properties will also provide a new innovative material pushing battery anode and cathode performance to a higher level. Allcomp produced hollow ligament foam, at a density of 0.03, 0.05g/cc, and 0.08g/cc. In the brief period afforded by Phase I we thermally and structurally tested the material in manner appropriate to HEP detector application. Foam ligament thermal conductivity was measured at close to 2 times that of copper. Further processing development proposed in Phase II will raise the conductivity to 1500W/mK, approximately 4 times that of copper. Phase II will further advance Allcomps graphitic foam processing. The graphite ligament material will become highly ordered pyrolytic graphitic. Phase II will focus on varying the chemical vapor deposition variables to improve the quality of carbon deposition. Our objective is to reduce the surface defects in the thinwalled graphite ligaments. Gains in ligament graphitic quality is reflected in increased electrical and thermal conductivity. Sandwich structures with this advanced foam will be made and thermally tested. Active cooling of the structures with both air and liquid will embrace the realm of future HEP tracking applications. Through a collaborative effort with battery development teams, this material will be studied for application of anodes and cathodes. Light weight conductive graphite foam is an enabling material for the next generation extremely lightweight detectors for high energy physics experiments. Hollow, low mass graphitic foam is under evaluation for advanced cathodes for batteries. Advanced high performance heat exchanger and energy storage devices for industry, aerospace, nuclear, and power generation, power storage, and many other applications can be developed using graphite foam. As an example, researchers at the Oak Ridge National Laboratory (ORNL) are proposing.