UFC - Ultra Fast Ceramic

UFC - a Breakthrough in Scintillation Materials
Siemens is the technology leader in medical Computed Tomography - we offer the world's fastest rotating CT system1 based on out cutting-edge UFC (Ultra Fast Ceramics) detector technology


Siemens detector competence
After more than 25 years of experience in developing, designing, manufacturing and maintaining CT detector systems, Siemens has gained unparalleled insights and know-how in scintillation technology. Well-proven in the clinical setting, Ultra Fast Ceramics offer the outstanding properties that will help advance other fields and applications, too. We now offer our UFC technology to other industries for state-of-the-art X-ray analysis and non-destructive inspections.


Our competence becomes your success
Whatever your industry and focus is - whether you strive to improve process and quality control, or to drive materials research - we can help you achieve your goals. Here you can find out more about our high-performance scintillator material. Challenge us - and discover how best to benefit from our leading expertise and experience.


UFC - Technology


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.

UFC - Ultra Fast Ceramic

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.

How fast is UFC?

Due to its fast decay behaviour and extremely short afterglow, Siemens UFC scintillator material is optimized for use with the fastest CT scanners, with rotational speeds well under 0.4 seconds.

How fast is UFC

In high-speed cardiac imaging, UFC requires no compromises in the number of image projections or any other correction algorithms which would impair image quality. UFC's primary advantage is its speed in combination with other unique properties – from minuscule drift, to short afterglow and excellent mechanical behaviour and handling.


Since scanners are becoming increasingly faster, this advantage of fast decay times continues to gain in importance in medical imaging as in other dynamic applications.

Data Sheet

1. Properties

1.1 Physical Properties

1.1.1 X-ray and γ - Properties

X-ray Attenuation Coefficient, based on: μ = 1/d ln (I/Io)

Tube Voltage (polychromatic)

Attenuation Coefficient

30 kV

μ = 13.00 mm-1

50 kV

μ = 4.99 mm-1

80 kV

μ = 5.61 mm-1

120 kV

μ = 4.62 mm-1

150 kV

μ = 3.99 mm-1

Data based on experiments using a CT X-ray tube and filters 3.0 mm Al + 0.6 mm Titan; tungsten anode; attenuation coefficient of a 1.4 mm UFC detector.

Photon Energy (monochromatic)

Attenuation Coefficient

1 keV

 μ = 3230 mm-1

2 keV

 μ = 1360 mm-1

5 keV

 μ = 256 mm-1

10 keV

 μ = 167 mm-1

20 keV

 μ = 27.0 mm-1

50 keV

 μ = 2.25 mm-1

100 keV

 μ = 1.92 mm-1

150 keV

 μ = 0.688 mm-1

200 keV

 μ = 0.354 mm-1

300 keV

 μ = 0.160 mm-1

500 keV

 μ = 0.0803 mm-1

1000 keV

 μ = 0.0451 mm-1

Data based on calculations for mono energetic radiation


a) Temporary Radiation Damage (Drift)
Signal change (typical) = 0.4% at 120 kV/250mA; t=60s
1005 mm (focus detector distance). Filter 10 mm Al equivalent at 80kV.

b) Permanent Radiation Damage
No permanent damage observed during 10 years of operation and in measurement
with 30 kGray.


Uniformity of Spectral Linearity
Typical uniformity = 0.025% over a length of 10 mm using the dual energy method:
120 kV/ 194 mAs/ 1005 mm (focus detector) and
140 kV/ 126 mAs/ 1005 mm (focus detector distance)

1.2 Optical Properties

1.2.1 Optical Constants

Refractive index n = 2.2

Absorption Coefficient

μa = 0.19 cm -1

( λ < 630 nm)


μa= 0.0001 cm -1

( λ > 630 nm)

Scattering Coefficient

μa ca. 500 cm -1

( λ < 630 nm)


μa ca. 330 cm -1

( λ > 630 nm)

1.2.2 Point Spread Function (subject to future changes)




0.4 mm

0.6 mm

1.6 mm

0.8 mm

0.8 mm

2.7 mm

1.0 mm

0.9 mm

3.3 mm

2.0 mm

2.0 mm

6.9 mm

Gaussian shape:
FWHM 1) = full width at half maximum
FWTM 2) = full width at tenth maximum
Simulation for a flat wafer with no boundaries. No reflector was used.
X-ray tube voltage 140 kV, filter 2 mm Al/1.26 mm Ti.

1.2.3 Light Output Uniformity

Light output change < 1% over a length of 30 mm.
Uniform X-ray exposure uncoated ceramic.
Use of a reflector may affect this value.

1.3 Luminescence

1.3.1 Emission Wavelength Spectrum

Emission Wavelength Spectrum

1.3.2 Short Time Afterglow

Short Time Afterglow


• time 0 for tuning off source is known within ~0.2 ms
• decay to < 10-3 occurs within 0.2 ms
• a trend to teach 10-4 is seen at 2.5 - 4 ms


1.3.3 Long - Term Afterglow with Pulsed X-ray Source

Long - Term Afterglow with Pulsed X-ray Source

 • data interval is 1 ms 

• decay to 10-4 is seen after 1 ms and decay to < 10-5 within 10 ms 

• digitization noise becomes relevant below 10-5 

• a trend towards 10-6 is seen between 10 ms and 100ms 

 1.4 Bulk Properties 

 1.4.1 Density 

7.29 – 7.33 g/cm3 (99.95% of theoretical density) 

 1.4.2 Vickers Hardness (subject to future changes) 

 HV = 910 ± 50 (Force: 1.5 N, duration: 20 s, rate: 20 p/s) 

 1.4.3 Thermal Properties 

Specific Heat Capacity 

Cp ≈ 0.318 ± 0.016 Jg-1K-1 at 305 K

 Thermal Expansion Coefficient (volume) 

10.0 *10-6 ± 0.3 * 10-6 K-1 between 423 K – 873 K 

 Thermal change of light output 

The average change of light output is 6 GU/K (Temperature = from 301K to 310K) 

 Thermal Conductivity 

9.6 ± 1.4 Wm-1K-1 at 293 K 

 1.4.4 Electrical Properties 

Conductivity (dark) σd< 1 * 10-13 Ω -1 m-1

Photoconductivity (at typical light intensities) can be neglected.

2. Handling 

2.1 General Resistance

UFC is resistant to all kinds of oil, solvent and water. It dissolves in concentrated mineral acids.

2.2 Weather Resistance 

No change in characteristic properties after 3 months at an atmosphere of 100% O, a relative humidity of 100% and a temperature of 70 °C (158°F).

2.3 Machining Properties 

UFC may be precision machined and processed using all kinds of abrasive methods as sawing, lapping, polishing as well as etching.

2.4 Handling Tools 

The UFC needs to be handled according to the rules of good craftsmanship. It may not be handled using smooth metals (up to non-hardened steel). Metallic contaminations are difficult to remove.

2.5 Environmental Safety 

Due to its non poisonous nature UFC has no impact on the environment unlike other solid state scintillation materials.

3. Customizing 

3.1 Form 

Rectangular wafers or crude blocks.

Edge Length:

min: 109 mm ± 0.01 mm


max: 116 mm ± 0.01 mm


min: 1.49 mm ± 0.003 mm


max: 29.30 mm ± 2 mm

Flatness: < 10 μm

3.3 Surface Roughness

Rz = 2.5 μm – 8 μm


Security screening

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.


Security Screening

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.

Food & Packaging

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.

Recycling and sorting of any kind

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.


Wood & Furniture Industries

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.


Our high-performing UFC and solid screen scintillators are designed, manufactured and assembled to highest standards of quality and performance in our high-tech detector center Forchheim in Southern Germany. Our scientists and engineers continuously work to perfect Siemens Healthineers UFC technology and production processes – at affordable prices.


Scintillation characteristics and quality depend to a high extent on the scintillator manufacturing method, specifically on grain size, powder concentration and other aspects. While we will not give you the exact recipe, here is a short outline of the process starting from highly pure raw material, to ceramics with a pore-free, homogenous crystal structure, to a fully structured array of finest UFC.

Synthesis of the ceramic material

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.

Synthesis of the ceramic material

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

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.


Sintering the Ceramic Material

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

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.

Enquiry form

We welcome your comments about our products and services. Please use the feedback form below. You will receive a response as soon as possible.