PIXIS-XF Fiber Optic Input X-ray Cameras from Princeton Instruments
Applications: X-ray micro tomography • X-ray phase contrast
imaging • Protein Crystallography • TEM
Front and Back-illuminated CCD's supported
X-ray photon counting capability
Proprietary Fiber Bonding Process *
Custom fiber taper configurations available
Removable phosphor screen and Be window option
Files are compatible with FIT2D software from ESRF
Easy to synchronizing with external UNIBLITZ PlIr blade x-ray shutter
(up to 30Kev)
The
PIXIS-XF is an advanced cooled digital x-ray camera system designed
for lens-less direct imaging of phosphor screens and other Lambertian
sources. When used with the optional removable x-ray scintillator
screen and the software-programmable, high-capacity or high-sensitivity
amplifier, this system can effectively provide x-ray photon counting
capability with up to 16-bit dynamic range. Phosphors screens are
available for 8 and 17 keV at a emission wavelength of 550 nm.
If Flexibility Counts The cameras are designed to detect x-ray photons for scientific
research needs to be flexible. X-ray scattering from complex crystals such
as proteins requires high dynamic range and low-noise readout, whereas
scattering from materials like polymers, fibers, and powders requires deep
cooling and rapid imaging to capture phase or morphological changes during
thermal or mechanical processing.
Phosphors Screen Options
(1) Gadolinium Oxy-Sulfide (with Terbium) powder phosphor –
Gd2O2S:Tb Princeton Instruments has developed two phosphors for 8 keV and 17
keV X-ray energies based on Gd2O2S:Tb powder. To provide highest possible
resolution, small grain material is used on a mirrored Mylar. When large
image area, high efficiency and lower costs are the considerations these
phosphors are recommended. The Gd2O2S:Tb is recommended for x-ray energies
< 33 keV as it has higher absorption efficiency and the CsI:Tl is
recommended for x-ray energies > 33keV.
(2) Cesium Iodide (with Thallium) crystalline phosphor For the application where highest possible resolution is a must
Princeton Instruments has developed phosphors based on CsI:Tl crystalline
structure for 8 keV, 25 keV and 60 keV X-ray energies. The crystalline
needle structure of CsI:Tl has a few advantages over the powder phosphors
(though it has lower absorption at x-ray energies < 33 keV). The needle
structure of CsI:Tl acts as a light guide to transmit visible light
generated from the absorbed X-ray photons and provides higher resolution
than powder phosphor and preserves resolution when x-ray energy changes a
little from experiment to experiment, and provides more uniform
light output. A special coating over the needle structure developed to
preserve the high resolution also protects it from the moisture in the
atmosphere.
Computer tomography (CT) has been used as
one of the most versatile techniques in the medical field since 1973 for
non-invasive investigations. Though CT has been used in many other fields such
as industry, archaeology, life and geosciences, it is limited in spatial
resolution. The best spatial resolution achievable by conventional CT
instruments is ~ 0.5 mm. Unfortunately, to examine the internal structure of
extremely small objects at a sub-millimeter scale, this technique is
insufficient.
Micro computer tomography (µCT)overcomes this limitation
with the availability of high-resolution, high-dynamic range CCD cameras,
high-resolution scintillators, micro-focus X-ray tubes with an optical focal
spot of < 1 µm (or synchrotron X-ray source), and software algorithms to
reconstruct 3D images. A typical system consists of an X-ray source, a rotating
table with a sample holder and a CCD camera with a computer. Depending on the
X-ray source, i.e., a micro-focus X-ray tube or a synchrotron X-ray source, a
fiberoptic- or optical lens -coupled system is used to project an image onto a
CCD camera. The best resolution delivered by these instruments is around 4
µm.
Dessert Lizard Tomogram: 10243 voxels, @ 4 µm per voxel
Tissue engineered bone from a pig orbit reconstruction Note:X-ray CT Images: Courtesy of ANU-XCT
