UFC - Ultra Fast Ceramic

What is UFC?

Functional ceramics are all-important for high image quality. UFC or Ultra Fast Ceramic is a scintillator material which quickly and efficiently transforms radiation from the X-ray tube into light signals. These signals in the visible spectrum are in turn picked up by photodiodes, transforming them into electric signals, which are computed to become visual 2D or 3D images.

Conventionally, other single crystalline substances are used in X-ray detectors such as cadmium tungstate (CdWO4), or cesium iodide (CsI). In our Ultra Fast Ceramic we use a crystal lattice of rare earth compounds gadolinium oxysulfide (GOS). UFC has a large X-ray absorption coefficient and due to its fast decay, reacts very rapidly to changes in X-ray intensity. These properties make it the ideal scintillator not only for time-critical medical imaging, but also for other fields and dynamic applications.

What's the difference?

UFC is superior to conventional detector materials in many ways - from light output, to decay time and drift. This outstanding product has proven itself in the challenging field of medical imaging.

Now, we see our Ultra Fast Ceramic being used in more and more industries - in order to deliver ever-improving levels of accuracy and efficiency elsewhere.

Recently security has become a major issue at airports for baggage control, in public transport and other public locations such courtrooms, embassies and the like. Backscatter X-ray machines that look beneath the clothing can detect hidden weapons, explosives, or illegal substances. Here, fast detector speed is of great importance – UFC is the perfect choice.

The huge volume of cargo passing through airports and cargo controls at harbours, can occasionally be daunting, slowing down processes and causing inconvenience to both passengers and staff. Table-top systems equipped with fast detector technology can speed up screening and enables fast throughput.

Quality assurance and testing are critical in the food industry. Contaminant issues can adversely affect brand image, long-term success of a company and consumer safety. Food processing and packaging requires ongoing analysis of foreign particles (e.g. metal, plastics or glass splinters) and broken or insufficient filled packets.

Through the use of our UFC scintillator material, X-ray technology can identify what is in materials of any kind, sort regardless of their color and contamination, and recycle them. With this technology, substances can be separated according to their atomic weight and density. This makes it possible to separate elements of a material into different material types.

Non-destructive evaluation is becoming more popular in the wood and furniture industries, as precious resources need to be managed carefully and efficiently. Furthermore, various attributes of wood panels largely determine panel end-uses. New design and manufacturing techniques require improved performance and strength of wood panels – which correspond to their density distribution. Automated non-destructive analytical techniques give insights into wood and fibre properties, such as density, allowing a more cost-efficient approach to wood exploitation and furniture production. UFC scintillation materials are robust in handling and fast – boosting your production and your outcome.

Synthesis of the ceramic material

First the basic ceramic raw materials are dissolved in water. They contain rare earth oxysulfides and other compounds. With the application of heat, a chemical transformation takes place. Tiny rod-like crystallites of microscopic size grow from the supersaturated solution. Following the filtering off of water and subsequent drying, a powdered intermediate product results.

In the oven process which then follows, the powder is reduced in a gaseous atmosphere to the actual fluorescing detector material. This compacted powder now consists of the special UFC chemical formula.

Sintering the ceramic material

Scintillator ceramics must be optically translucent to transparent to ensure maximum transmittance of radiation. Only high-density ceramic with extremely low residual porosity, inclusions or grain boundaries (voids) meets this requirement.
 

Pressure-assisted sintering of the powder to a nearby 100% dense, homogeneous ceramic material allows the UFC properties required for detectors to emerge. Densification is achieved at very high temperatures with the simultaneous application of a compressive force of several tons.

Following cool down, the UFC pressed block is cut into wafers on a multi-wire saw with an extremely thin diamond wire. The wafers are then ground to their exact final size. In the next step, their physical characteristics are inspected.

Structuring the array

After the testing of the UFC wafer, a reflector layer is laminated onto it. The wafer is then structured and separated into UFC arrays. Each CT product line has its own requirements in regard to size, number, and layout of the pixels. The required structure is first transferred to the wafer, fully automatically and in two dimensions, using an ultrahigh-precision saw.

The interstitial zones of the pixels and the rear of the array are coated with a special reflecting polymer so as not to lose any of the light produced in the scintillator and to optically separate the pixels. Several tests are carried out to verify conformity with rigorous mechanical and optical tolerances.