STAR X-ray Source Accelerator Project
Thomson Backscattering Source

The overall design of the STAR electron accelerator provides a clear view of its various subsystems, including the three radiofrequency power stations (bottom left), the photoinjector and linear acceleration section (center/top left), and the two low-energy beamlines—one reaching up to 60 MeV (top right) and the other up to 150 MeV (bottom right). The light beamlines in the lower right direct the generated X-rays toward the SoftX and µTomo experimental stations. The entire accelerator spans 24 meters in length.

Paleogene mosquito trapped in Baltic amber
Deposit age: 40 million years
Mine/extraction area: Kaliningrad
Experimental station: µTomo@STAR

Amber is a resin that, once solidified, preserves plant and animal remains. Most inclusions are insects—primarily flies and mosquitoes—that remain intact for millions of years, providing essential information for understanding biological evolution. Microtomography offers a three-dimensional view of the insect, capturing even the details of its internal organs.

Virtual cross-section of a spent battery
Experimental station: µTomo@STAR

This tomographic section reveals the internal structure of the battery's active material, composed of eight button cells arranged in series, one on top of the other (only six are shown in the image). In the depleted battery, fractures and defects are visible, caused by its deterioration.

Outer and inner surface of a goldfish heart.
Experimental station: µTomo@STAR

The heart of goldfish (Carassius auratus) consists of four chambers: the venous sinus, atrium, ventricle, and arterial bulb. The image primarily highlights the ventricle, which has an outer compact layer and an inner spongy layer. On the right, the internal cavity structure is shown in white (with progressively smaller intertrabecular spaces as you move from the lumen towards the epicardial region) of the ventricle. This heart is used as a research model in the study of cardiac plasticity, allowing the analysis of tissue, molecular, and cellular aspects of the organ.

Tomographic projection of a human molar
Experimental station: µTomo@STAR

Transparent representation of the outer surface (enamel) and inner surface (pulp chamber) of a human molar. The internal space consists of a central cavity, occupied by the dental pulp, and the root cavities, through which nerves and blood vessels pass.

Tomographic projection of a larva in its cell
Experimental station: µTomo@STAR

The Megachile Chalicodoma Sicula is particularly common in Mediterranean countries. It builds a nearly waterproof nest by mixing sand and earth with a secretion from its labial glands. The nest has a spherical or hemispherical shape and can be found attached to rocks, house walls, or thin twigs of shrubs. Inside the nest, there are several elongated cells filled with honey and pollen. An egg is laid in each cell, from which the larva develops.

Obsidian from Sierra de las Navajas (Mexico)
Experimental station: µTomo@STAR

Tomographic representation of the outer surface (right) and the internal vesicles (left) of an obsidian. Obsidian is an effusive igneous rock characterized by its glassy structure. Its formation is due to the rapid solidification of lava. Unlike the "our" obsidians from Lipari, those from Sierra de las Navajas contain elongated vesicles in a specific direction (shown in blue). These tiny cavities play a significant role in determining their chromatic characteristics (color and surface shine) and mechanical properties (how they break under pressure). Obsidian has been used to create pendants or votive objects, as well as knives, arrowheads, or other cutting tools.

Tomographic projection of a zebrafish skeleton
Experimental station: µTomo@STAR

The zebrafish, or Danio rerio, is a small freshwater fish that is easy to breed in the lab. It is widely used in pharmacological and toxicological studies, as well as in the evaluation of new therapies, due to its genetic similarity to humans and its ability to absorb molecules dissolved in water. For this reason, it is also considered an indicator species for marine ecosystem pollution.

Internal pores of a polymer sample
Experimental station: µTomo@STAR

To highlight the pores and surface of a polymer sample (created using 3D printing), only the surface of the "digital twin" obtained through X-ray microtomography was sectioned.

3D printing technology is now used in many fields, such as healthcare, construction, and the transportation industry, due to its ability to reproduce objects with even very complex shapes. However, the quality of the parts produced can be affected by the manufacturing process, leading to various types of defects such as porosity or slag inclusions. Understanding the role of these defects will help make this production technique (known as "additive manufacturing") increasingly effective.

External surface of hydrogen embrittled steel
Experimental station: µTomo@STAR

A steel sample subjected to 700 bar of hydrogen was pulled to failure in order to assess its tensile behavior. These tests, conducted in collaboration with RINA S.p.A. – Centro Sviluppo Materiali (CSM), allow for the observation of fractures that form internally in steel samples considered as potential materials for hydrogen containment and distribution, supporting the ongoing energy transition. Notably, the fracture surface exhibits a jagged profile. The sample diameter is 6 mm.

Cross-section of a goji berry: seeds and filaments
Experimental station: µTomo@STAR

This image shows a cross-section of a goji berry (Lycium barbarum), displaying its flattened, rounded seeds and the remnants of the internal partition walls. The section size is 5 mm, with the smallest details measuring in hundredths of a millimeter.

Revealed Staurolite crystal
Experimental station: µTomo@STAR

This Staurolite crystal (an aluminum and iron sub-nesosilicate mineral) is embedded within a volcanic rock and cannot be seen from the outside. Its appearance is characteristic of prismatic cross-shaped twin crystals. The Staurolite, like the other inclusions in the rock, is made visible by removing the surrounding rock from the tomographic image.

Calabrian chili pepper: skin, flesh, seeds, and filaments
Experimental station: µTomo@STAR

Transparent rendering of a Calabrian chili pepper (Capsicum annuum, Calabrian cultivar). This rendering displays the entire fruit, including the morphology of all its parts, such as the internal structure of the seeds, the membranes surrounding them, and the stratigraphy of the outer pulp.

Internal trabeculae of a chicken bone
Experimental station: µTomo@STAR

Cross-section of a chicken femur. The trabeculae, or spongy bone tissue, are interconnected in various ways, forming communicating spaces known as marrow cavities, which are filled with bone marrow, blood vessels, and nerves.

Bones and cartilage of a very young gecko
Experimental station: µTomo@STAR

The skeleton of a young common gecko (Tarentola mauritanica) is displayed in great detail. The smallest phalanges are similar in size to a human hair.