SLAC National Accelerator Laboratory uses massive quantities of aluminum foil to perform "bake out" of their equipment. In a typical bake out, the equipment is blanketed in foil, wrapped with electrical heat tape, and then covered in foil again. Heat tape is used to heat the metal chamber just enough to loosen any residues that could cause trouble. The aluminum foil helps spread the heat evenly. | Photo of SLAC

Where there are physicists, there is likely foil. I’m not even talking about “FOIL” - the mnemonic device to helps you multiply binominals. I’m talking about plain wrap-your-sandwich-in-it aluminum foil. It’s just a theory, but then so is the Standard Model.

Ask any physicist working with a particle accelerator, x-ray or other light source about their lab equipment. No matter how precise and expensive, it’s probably wrapped in foil. The reason: aluminum foil is lightweight, inexpensive and works wonders as an insulator for temperature, electricity and magnetic charges. Here are a few ways our Energy Department researchers find the shiny stuff crucial to their mission:  

1. Performing a “bake out”

Lawrence Berkeley Lab’s Advanced Light Source alone goes through about 20,000 square feet of the stuff each year, enough to cover a major league baseball in-field. It's likely they're using it to "bake out" their equipment, the same as does SLAC National Accelerator Lab. SLAC has a couple great video and article about the “bake out,” a maintenance procedure that involves metal strips, metal tape, and lots of foil that allows their equipment to keep its near-perfect vacuum.

2. Target practice for your x-ray laser

Have you ever accidentally put aluminum foil in the microwave and turned it on? I imagine that is similar to experiments that researchers use to explore conditions inside stars and giant planets. When SLAC or Berkeley Lab turn their powerful x-ray lasers onto, yes, a piece of foil, they are recreating conditions only found at the centerof suns. Earlier this year, SLAC heated a piece of foil to 3.6 million degrees F (or about 2 million degrees C). And they aren’t alone. Berkeley, Lawrence Livermore, Brookhaven, Princeton Plasma Physics Lab all run similar experiments involving x-rays and foil. Just one big microwave unlocking the secrets of the universe.

3. Growing nanoscale crystals for the next generation solar cells

In 2009, Berkeley Researchers published a work in Nature titled, “Three-dimensional nanopillar-array photovoltaics on low-cost and flexible substrates.” If you read into this (much easier to read) article from Berkeley Lab, it turns out these researchers found out a way to grow crystals on aluminum foil sheets (a.k.a. -- “low-cost and flexible substrates”), peel them off like stickers and work them into flexible solar cells.

4. Protecting your atomic force microscope from static

You may not notice it immediately in this photo, but Antonio Checco’s desk is completely wrapped in foil. His reasoning for this: aluminum foil helps get rid of static. Understandably, he was tired of frying his equipment with the static electricity his body generated walking on the plastic floors, so he covered his desk in foil and grounded it. You can read his full explanation in this 2010 Q&A.

5. Protecting yourself from invasive radio signals

This actually isn't advancing science, but this is an article about aluminum foil – on a government website. Where does your mind immediately go? Tin foil hats -- and that’s exactly what we wanted you to think. Though, even if you were wearing a shiny hat to block our radio signals, you may find, as did four researchers at MIT, that if these waves existed -- which we can neither confirm nor deny -- your headgear would only amplify the waves.

Next time you are unwrapping your sandwich remember that Energy Department researchers maintain their machines, develop new solar cells, and create hot dense matter with the same versatile aluminum foil.