Nikon Metrology

New Scientist magazine shares the history of X-ray tubes

Computed tomography, Nikon Metrology, X-ray and CT Inspection

A recent article in the New Scientist magazine takes a look at the CT scans of X-ray tubes, created by Herminso Villarraga-Gomez. Read below to find out what inspired Herminso to create these images and how they were taken.  


Modern Rotating Anode Tube - Herminso Villarraga-Gómez, Nikon Metrology, Inc., Americas.

A new addition to ‘The Evolution of X-ray Tubes’ collection of images: Modern Rotating Anode Tube – Herminso Villarraga-Gómez, Nikon Metrology, Inc., Americas.


This is an X-ray image of a rotating anode X-ray tube from modern times (1960s-to-today). The rotating anode tube is an improvement of the Coolidge tube, which helps with the dissipation of heat at the focal spot. A considerable quantity of heat is generated at the anode by incidence of electrons when X-rays are being generated. The use of rotating target anode, which is usually provided in the form of a disc, avoids the electrons hitting just at one given spot at the target and concentrating all the heat on it. The rotation spreads the heat along the entire disc when the electron beam is incident on a region away from the disc center. (The picture above was taken with a Nikon XT H 450 CT system housing a modern X-ray tube).


What was the motivation behind this project?

I’m a physicist and an optical engineer currently working in the tech industry (at Nikon Metrology) with X-ray machines. Since 2015 (the International Year of Light and Light-based Technologies—as declared by the United Nations), I decided to start a project of imaging (with X-rays) the interior of technological evolutions—it can be called “the evolution of things”. It started with the publication of a first submission to the Optics and Photonics News (OPN) that appeared in the December 2015 issue. The image submitted at that time was called “The Evolution of Electric Light Bulbs” featuring an Edison style incandescent light bulb, a fluorescent light bulb, and a LED light bulb. The next year, in 2016, I created the “the Evolution of the Computer Mouse” to feature the transition from wired electro-mechanical trackballs to a wireless optical/laser tracking mechanism. This past year my submission theme to the OPN was “The Evolution of X-ray Tubes”.

Why the evolution of things?

I very much like the theory of evolution because not only can it be applied to natural selection in the heritable characteristics of biological populations over successive generations but also to the evolution of ideas, or to the evolution of technological innovations. The big advantage with the latter is the evolution of technological innovations can be easily perceived in our current times without the need to wait for time-scale transitions that cover several generations of species as the case of biological evolution. My inspiration comes from seeing X-ray images every day in my current job at Nikon Metrology. My focus toward X-ray technologies started in 2012 when I started my PhD at the University of North Carolina at Charlotte (USA) with a project that involved using X-rays for metrology—for dimensioning things (not only for imaging).

How were the images created?

The images were taken using an X-ray CT system. I used a Nikon CT system for my radiographs of the evolution of things. However, since CT (or CAT scan) is used for 3D imaging from multiple radiographs but I was only interested in a single 2D radiographic image, I limited the use of the CT system capability to shoot only a single X-ray image, to obtain the best radiograph that I could possibly get for my object of interest.



Take a closer look at The Evolution of X-ray Tubes project.

Read the New Scientist article – ‘Ghostly images show the history of x-ray tubes’.