In particle accelerators, electrons are pushed to extreme energies by electromagnetic fields that oscillate inside evacuated metal cavities. Those cavities are usually made of copper. Even in SLAC’s most advanced accelerators, it is the strength of the copper material that determines how much field we can apply and how much acceleration we can achieve. The same holds true for tabletop accelerators used in materials processing and cancer treatment. Today’s cavities are made of “dead soft” copper, which is weaker than most plastics. But switching to other forms of copper that are 10 to 100 times stronger – stronger than some steels – could help us overcome the current limitations on acceleration. This talk will describe how SLAC scientists are using X-rays to explore the microstructure of various forms of copper under realistic accelerator operating conditions. Learning how to employ copper’s super-powered states, maintain its strength and guard against damage will enable more compact and powerful particle accelerators.