Radiation-Tolerant Thermal Interface Material with High Thermal Conductivity and Adhesion for HL-LHC Applications

The Large Hadron Collider in Switzerland is the largest particle accelerator in the world.Upgrades bringing higher resolution (higher luminosity) is called HLLHC and will require improved lightweight materials.Thermal interface materials having higher thermal conductivity (> 4 W/mK) with low atomic mass and excellent radiation-resistance are required to achieve tight tolerances on detectors.The objective of the Phase I effort was to make a polymernanostructured carbon composite with a microstructure with nearly isotropic thermal conduction in excess of 4 W/mK using a polymer system that retains flexibility while leading to improved adhesion and high radiation-resistance.The Phase I effort produced 20 different samples with through-thickness thermal conductivity in excess of 4 W/mK, with values ten times higher than presently used.Radiation exposure under a neutron fluence of 1x1016 neutrons/cm2 showed that the material remained flexible.Adhesive strengths were double the target value.All Phase I objectives were met.The Phase II work will build upon the Phase I results and apply tailored microstructures to other polymer systems in order to make thermal interface materials capable of bonding to porous carbon structures used within the High-Luminostiy, Large Hadron Collider.The Phase II research will show that it is possible to maintain the high specific thermal conductivity achieved in Phase I while increasing radiation-tolerance and make stiffer interfaces for improved detection.Thermal interface materials with higher thermal conductivities can be used for dissipating heat from a wide range of electronic devices.These materials also have the ability to shield electromagnetic interference and can be used as infrared heaters for a variety of applications.Filled-polymers with enhanced thermal conductivities and electrically conductivity can be molded, extruded, or cast to produce new grades for more demanding applications.