It pains me to say this, but sometimes I’m too busy to make blog posts. It’s not that I don’t love you, dear reader. Even when I’m not writing to you, I think about you. In fact, it’s especially when I’m not writing to you that you’re on my mind.
So let’s try this new thing. Every Friday, I’ll post a photo of some cool particle accelerator thing along with a short li’l description. If I keep them short, I can totally keep to a weekly schedule. Bonus for you: short = readable!
Let’s start with this one:
That giant yellow thing is called a cryomodule.
Ok, so you know how your laptop gets warm after you’ve used it for a while? That warmth comes from electric current moving through copper. Copper is a good conductor but it’s not perfect. Some of that electric current gets dissipated as heat.
Accelerators can require huge electric currents, either to power magnets that steer the beam, or to create huge electric fields that accelerate the beam. (Remember, we talked about this?) Well, so if copper gets hot in your laptop, think how hot it would get if you pumped megawatts of power through it. Instead, accelerator components can be built with superconductors. Superconductors have perfect DC conductivity, and near-perfect AC conductivity. So you can move those huge currents without melting your machine.
What does all this have to do with a cryomodule? Well, superconductors need to be cold in order to work, where “cold” usually means “a few degrees above absolute zero”. This means you need to flow liquid helium (which is really super cold) across your superconducting components. A cryomodule accommodates and insulates all that insanely complex plumbing. It also manages the electrical transition between a cold superconductor and a room-temperature power source, houses tuners and diagnostic equipment, damps mechanical vibrations, and does some other stuff that it would take too long to explain right now.
Look, here’s another photo of some cryomodule innards:
You're looking at a low-quality cell phone photo of a shockingly complicated device.
Surprisingly, that big open pipe is not where the accelerator beam goes. It’s the return pipe for the helium, which evaporates as it soaks up heat from the accelerator. The beam pipe is just below the gas return pipe, and it’s sealed off so that it stays clean and pristine.
Next Friday: The cleanest room you have ever seen.