can X-rays be refracted?

Question

Light can be refracted by traveling in various transparent mediums. Light is just one of the electromagnetic wave ranges. There are others, including Xrays and Gamma rays. It seems we can not focus these other kinds of rays. So I guess that they can not be refracted. Why not, are they too short?

ElectroMagnetic waves spread out and would be able to go around any atoms they encounter. What is it in the medium that makes them bend (refracts them)?

Answer 1

The total light wave inside a medium is the sum of the incident wave plus the wave which results from the excitation of the electrons--for when an electron is jiggled, it sends out its own light pulse.

You can get the whole effect by adding up the contributions from all of the oscillating electrons plus the incident wave. So the mechanism of refraction is the jiggling.

Now the jiggling electron itself behaves very much like a mass on a spring. The spring has its own frequency. For driving frequencies which are much higher than this natural frequency, the spring response is very small (because when it tries to go one way, it's almost immediately nudged in the other). Hence for frequencies well above the natural atomic frequencies--which are usually in the visible to near UV range but well below the Xray range--there is very little refraction. In fact, Xray frequencies are high enough to simply kick electrons off of atoms, rather than make them jiggle. This is why they're dangerous.

Answer 2

Sharper focusing of hard X-rays has been achieved with a device developed at Argonne National Lab.

Because of their high energy, X-rays are hard to focus: they can be reflected from a surface but only at a glancing angle (less than a tenth of a degree); they can be refracted but the index of refraction is very close to 1, so that making efficient lenses becomes a problem; and they can be diffracted, but the thick, variable pitch grating required for focusing is tricky to achieve.

Answer 3

Elementary physics -- any beam of energy can be diverted (refracted). Water refracts any rays shot into it, including X-rays and gamma rays. Higher energy waves are not refracted as much by water as, say, the visible light spectrum, but they are refracted to some degree.

Answer 4

No. X-rays can be manipulated by reflection, diffraction and interference effects but not refraction because there are no materials with suitable refractive indices to cause refraction.

Answer 5

Thank you, R.E. Taylor, for your answer. I learned something important today from you.