Scientists with X-Ray Eyes

JILA scientists Margaret Murnane and Henry Kapteyn run a lab at JILA together. They’re also married to each other. They specialize in studying lasers and light. One of the things they like to do in the lab is watch what’s happening inside molecules. They’ve come up with a very clever way to do this.

First, they zap molecules they want to study with a short burst of laser light. The laser light gently kicks the molecules and starts them shaking. Next, they send another burst of light from a different laser into the shaking molecules. This burst of laser light does something extraordinary: It plucks an electron out of each molecule that is shaking! What’s more, the intense energy of the laser speeds up the electrons so they first fly away from the molecules and then fly back toward the molecules like a boomerang. Finally, the electrons smash back into the same molecules they came out of. The electrons’ boomerang flights take about 2 quadrillionths of a second.

When the electrons smash back into their molecules, a burst of X-rays comes out of the molecules. Margaret and Henry study the X-rays to learn about different changes that can occur inside the molecules after they’ve lost an electron and then had it smash back into them.

Sometimes, the molecules can change in ways that make it hard to emit X-rays. For instance, the place the electron came from can disappear. When that happens, it’s hard for the electron to get back inside its molecule. If the electron can’t get back inside, then X-rays aren’t emitted.

Other times, the place the electron came from is still there, almost like it’s waiting for the electron to return. When this happens, it’s easy for the electron to get back inside its molecule, and the molecule emits an X-ray.

Margaret and Henry are still studying this interesting way to “look” inside molecules. They hope to use it to uncover new information about how atoms and electrons move when they’re part of a molecule. - Julie Phillips

Vocabulary

Atom:Particle that is the smallest amount of a unique substance like oxygen or gold.

Electron:Part of an atom that exists as a cloud around the nucleus, or main part of an atom.

Laser:Device that emits intense light

Molecule:Particle made up of one or more atoms linked together

X-ray:A very high energy form of light that eyes can’t detect.