What is X-Ray Spectroscopy?

X-Ray Spectroscopy, a technique that uses beams of charged particles to excite atoms, trigger energy level transfers and collect data by measuring photons, is one of the most useful analytical tools available to scientists. By analysing wavelengths that fall in the X-Ray region of the electromagnetic spectrum, scientists can unlock valuable insight into the structural, chemical and elemental characteristics of matter.

How X-Ray Spectroscopy works

X-Ray Spectroscopy relies on energy level shifts to generate data. The process starts by exciting atoms using a beam of charged particles. Once excited, electrons are forced to move to a higher energy level. As the electrons return to their pre-excitation level, energy is released in the form of photons. Specialised instruments called X-Ray Spectrometers are used to measure the unique wavelengths and radiation dispersion patterns of these photons. Data is used to identify different elements within the matter, determine concentrations and map atomic structure.

Within the X-Ray Spectroscopy niche, scientists can choose from two specialised techniques. Wavelength-Dispersive X-Ray Spectroscopy (WDXS) uses a crystal to diffract light while Energy-Dispersive X-Ray Spectroscopy (EDXS) uses a beam of charged particles.

The origins of X-Ray Spectroscopy 

While German physicist Wilhelm Conrad Röntgen is credited with discovering X-Rays in 1895, it wasn’t until the 1900s that the technology was used for Spectroscopy. A pair of British physicists used a crystal to analyse the interactions between X-Ray radiation and atoms. They coined the term ‘X-Ray Crystallography’ and went on to win the 1915 Nobel Prize in Physics for their contributions to science.

Applications for X-Ray Spectroscopy

X-Ray Spectroscopy is an incredibly versatile tool used across a wide range of scientific disciplines and industries. Here’s a glimpse at just some of the different types of spectroscopy uses:

Archaeology

As a non-destructive analytical technique, X-Ray Fluorescence (XRF) Spectroscopy is a valuable tool within the archaeology sector. Low-level radiation is used to excite atoms, determine the elemental composition of archaeological samples and generate unique “fingerprints” which can be used to track the geological sources of rocks, tools, weapons and other ancient artefacts.  

Astronomy

From observing black holes to detecting the unique spectral signatures of rocks found on Mars, X-Ray Spectroscopy has some truly astronomical applications. For example, the state-of-the-art Alpha Proton X-Ray Spectrometer is just one of many sophisticated instruments onboard NASA’s Mars Curiosity Rover.

Engineering

Back on Planet Earth, engineers rely on X-Ray Spectroscopy to identify different chemical elements found within matter. The ability to gain high-resolution insight into the composition of materials helps engineers make informed decisions when designing and executing projects.

Want to go beyond archaeology, astronomy and engineering applications? Find out more about the types of spectroscopy used for qualitative and quantitative analysis in our complete guide: ‘What Are the Different Types of Spectroscopy?’