What are Soft X-rays
Soft X-rays are electromagnetic radiation with wavelength in the range of 0.12 nm to 5nm (or 5 millionths of a millimeter). This range of “light” lies between UV (like the light from a tanning bed) and Hard X-rays (which you might receive at the dentist’s office).
Photons in this range of the electromagnetic spectrum have energies of 250eV to 10,000eV.
Due to the inherently short wavelength of the soft X-ray, one is able to use this “light” to see extremely small features and to make minute features.
Within the soft X-ray regime, there is a region called the “water window” (2.32-4.36nm) in which the “light” passes through water, but is absorbed by Carbon, Oxygen, Nitrogen and Sulphur. In this region brilliant images of biological materials can be capture that are unavailable with other techniques.