High Resolution Low Energy X-ray Microradiography
Using Single Crystal Scintillators
J. Tous, P. Horodysky, K. Blazek / Crytur Ltd., Turnov, Czech Republic
J.A. Mares, M. Nikl / Academy of Sciences of the Czech Republic, Institute of Physics, Prague, Czech Republic
M. Kucera / Charles University, Faculty of Mathematics and Physics, Prague, Czech RepublicHigh resolution X-ray camera for micro-radiography based on CCD detector and precise thin YAG:Ce or LuAG:Ce single crystalline
screens and its different applications are described and presented. YAG:Ce or LuAG:Ce inorganic crystal scintillators arecharacterized by good mechanical and chemical stability, non-hygroscopicity, high scintillation efficiency and fast decays [1].
Screens prepared from these crystals can be used in equipments for detection of different kinds of radiation and particles (UV, VUV,electrons or ions or their beams, X- or gamma rays). The resolution achieved is about 1 micrometer at low energy X-rays.
Scintillation Materials for Imaging Screens
5

Intensity (arbitrary units)

4 1053.5 1053 1052.5 10

X-ray excited
luminescence

YAG:Ce (Y3Al5O12) Yttrium aluminum garnet
LuAG:Ce (Lu3Al5O12) Lutetium aluminum garnet

YAG:Ce0.32%
LuAG:Ce0.12%
BGO x552 10Czochralski or Liquid Phase Epitaxy grown51.5 1051 10x5

Screen thickness down to several micrometers

45 100200

400600

Wavelength (nm)

5 mm thin YAG:Ce screen

LPE LuAG:Ce sample

LPE LuAG:Eu screenThin YAG:Ce screen on FOP

Yttrium aluminum garnet activated by cerium is a fast scintillator with excellent mechanical andchemical resistance. YAG:Ce scintillation detectors are the preferred choice for electron
microscopy, beta and X-ray counting, as well as for electron and X-ray imaging screens.
Lutetium aluminum garnet activated by cerium or europium is a scintillator with a high absorption
to X-ray radiation and excellent mechanical and chemical resistance. LuAG:Ce scintillation
detectors are the preferred choice for X-ray radiography imaging screens.

High Spatial Resolution Imaging Systems
High resolution imaging system is a combination of a high sensitive digital CCD camera andan optical system with a thin scintillator imaging screen.
Very thin (down to 5 microns) screens of YAG:Ce were developed for imaging applications
requiring high spatial resolution [2]. The 2D-spatial resolution of an X-ray or other ionizing
radiation imaging systems is one of the critical parameters in non-destructive microradiography and radiation beam inspection.
High-resolution X-ray imaging digital camera
SEM image of the test grid

The X-ray CCD camera was tested eitherwith several small biological objects (insector small animals) or with special grids. The
2D-spatial resolution achieved in theimages was about 1 micrometer [2].
Radiographies of the 8-microns grid imaged by Czochralski
LuAG:Ce (left) and YAG:Ce (right )thin plates

The grid imaged by P43
powder scintillator

Detail of thebroken wire
The high resolution of the system withYAG:Ce thin screen is compared to a
standard P43 phosphor screen using thesame conditions. The objects is a gold gridwith the wires 8 microns wide. The images
were taken by using the 20 micrometers
thick YAG:Ce imaging screen or 20 microns
thick phosphor P43 (GADOX), both onquartz glass.

High Resolution Application in X-ray Radiography

The images were taken using amicrofocus X-ray tube with Cu
anode@ 40kV/2mA
X-ray radiography of a mouse kidney

X-ray radiography of a mouse brain

X-ray radiography of a spider

Aluminum foams

A walnut

X-ray inspection of fine wires in a data cable

Other applications:- X-ray spectroscopy- X-ray topography- X-ray beam adjustment- X-ray thin films diffraction- X-ray optics adjustment- X-ray microfocus spotmeasurement- X-ray imaging in industry- X-ray food inspection... and many others[1] J.A. Mares, A. Beitlerova, M. Nikl, N. Solovieva, C. D'Ambrosio, K. Blazek, P. Maly, K. Nejezchleb and F. De Notaristefani, Rad. Measur. 38 (2004), 353-356.
[2] J. Tous, K. Blazek, L. Pina and B. Sopko, Rad. Meas. 42 (2007), 925-928.

The support of Czech GA AV project KAN300100802 is gratefully acknowledged.