Photonic Science x-ray phase contrast micro tomography and nano tomography X-ray NDT Imaging

X-ray phase contrast micro tomography and nano tomography X-ray NDT Imaging detector Systems

Contact
RSSPrint

French office: Tel 00 33 (0) 4 76 93 57 20  |   Head office UK: Tel 00 44 (0) 1580 881199

info@photonic-science.co.uk

Transmission X-ray Microscopy

X-ray microscopes produces contrast using the difference in absorption of soft X-ray in the water window region

Wavelength region: 2.3 - 4.4 nm, corresponding to photon energy region of 0.28 - 0.53 keV is where the carbon atom (main element composing the living cell) and the oxygen atom (main element for water) deliver good imaging contrast.

A typical set up consists of polychromatic source used with condenser optic that relays the radiation onto the sample and a Fresnel zone plate is used in order to magnify the image onto the camera. The latter is a very high resolution cooled high sensitivity CCD camera coupled to a state of art scintillator using high NA lens with 1.4 micron effective pixel size.

An alternative solution using direct exposure of the CCD to soft X-ray is also available with 13 microns pixel size.

An other technique, known as lens less coherent diffraction imaging is emerging as a potential technique for enhancing resolution down to 1.5 the radiation wavelength. It also enables to eliminate a low transmission FZP.

Combined with XANES (by taking an image above and below the absorption edge of an element), the camera can unveil information about the chemical state of components in the sample.

Transmission X-ray Microscopy

Transmission X-ray Microscopy

Transmission X-ray Microscopy Recommend products:

X-ray XEM LC camera X-ray FDI LC camera X-ray Image Star camera

Ask an expert

X-ray Phase Contrast Imaging

X-ray Phase Contrast technique is used to unveil edge contrast in low Z materials that are barely detectable using conventional X-ray transmission imaging technique.

The contrast in X-ray images is normally generated by the difference in X-ray absorption for different materials.

The X-ray absorption coefficient is roughly proportional to the fourth power of the atomic number Z, making the imaging of objects consisting of low-Z elements like carbon, nitrogen and oxygen difficult. For nearly all elements the real part d of the complex index of refraction n (n = 1 – d + ib) in the X-ray region is larger than the imaginary part b.

As a consequence, a very subtle variation (phase shift) is introduced in the X-ray path, resulting in contrast changes around the edges of an object as light and dark fringes. Those are high spatial frequencies that can only be sensed by a very high resolution detector with excellent MTF response and good dynamic range as we are trying to image subtle intensity changes over a large background.
A highly spatially coherent X-ray source combined with a very high resolution detector are used to produce a phase contrast imaging set up.

Phase retrieval software can be offered for recovering quantitative information of a sample with known density, thus helping refining 3D tomographic reconstructions.

X-ray Phase Contrast imaging

X-ray Phase Contrast Imaging

X-ray Phase Contrast Imaging Recommend products:

X-ray VHR camera

Ask an expert

Diffraction Enhanced Imaging

Diffraction Enhanced Imaging is used to unveil edge contrast in biological samples thanks to the detection of very subtle X-ray scattering changes.

An analyzer crystal is positioned between the sample and the image detector. The narrow angular acceptance of the analyzer allows to characterize the refracted and scattered X-rays going through the sample.

Scattering angles larger than the angular acceptance of the analyzer, typically few micro radians, will not be transmitted by the analyzer, this provides extinction contrast.

Equally, only the density variations across the sample that leads to micro radian refracted X-rays will go through the analyzer, this provides refraction contrast. Those subtle differences in scattering and refracting angles produced by the samples will be converted into intensity differences, which are then detected by a high resolution X-ray detector.

Sufficiently bright source must be used in order to collect enough flux after a low acceptance solid angle analyser, equally, a very high resolution detector must be used in order to sense very subtle edge contrast changes over a range of high spatial frequencies.

Diffraction enhanced imaging

Diffraction Enhanced Imaging

Recommend products:

X-ray VHR camera

Ask an expert

X-ray Topography

X-ray Topography reveals cracks in single crystal substrates using X-ray beams that have been Bragg-diffracted by a crystal to image it.

X-ray topographs will show the distribution of various singularities that affect the Bragg reflection used in particular crystal defects such as precipitates, individual dislocations, stacking faults, domain or phase boundaries.

Topography relies on the fact that singularities or inhomogeneities can affect the spatial distribution of diffracted intensity and hence result in contrast.

In its usual meaning, topography can only be performed on single crystals, or on single grains within a polycrystal.

There is a wide range of variants: in transmission or in reflection, with a monochromatic beam, 8keV or with a white beam up to 100 keV, with a divergent beam or very well collimated beam, depending on the sample thickness and material.

A high resolution detector is necessary in order to record intensity changes produced by subtle diffracted beam path differences.

Scanning over large areas such as with Silicon wafers requires the use of detectors with good sensitivity, 100% duty cycle in order to maintain good inspection throughput.

X-ray topography

X-ray Topography

X-ray Topography Recommend products:

X-ray VHR camera X-ray FDI camera

Ask an expert

X-ray Micro and Nano Tomography

X-ray Tomography allows a 3D reconstruction from a series of radiographs for different angular positions of the sample down to sub micron resolution.

Typically a full tomographic data set will require in the order of few hundreds to a few 1000s radiographs using a 3D reconstruction Feldkamp algorithm. Optical Cone beam / fan beam reconstruction are used, with the sample rotating in a fixed plan / helicoidally around an axis perpendicular to the beam.

The total acquisition time is in the range of few seconds per frame, it depends very much on the source brilliance / geometry. 100% duty cycle detectors with simultaneous read out / exposure allows to save up to 50% of the scanning time.

Resolution down to a few hundred nanometers can be achieved by using a small focal spot source and reasonable geometric magnification. The recorded data is often several Gigabytes and can be processed using the massively parallel calculation capacity of GPUs.

Micro tomography can be combined with phase contrast imaging, either in a qualitative way (“edge enhancement”) or, more quantitatively, including phase retrieval (“holotomography”). Very high resolution cameras allows the build of scanners with sub micrometer spatial resolution whilst keeping compact dimensions and good sensitivity.

X-ray micro tomography and nano tomography

X-ray Micro and Nano Tomography

X-ray Micro and Nano Tomography Recommend products:

X-ray VHR camera X-ray FDI camera X-ray XEM camera

Ask an expert

Industrial PCB X-ray Inspection / Digital X-ray Radiography,

X-ray cameras are used to detect porosity, inclusions, cracks and even grain structure within a variety of cast components and in welded joints.

With the increasing production of many new types of components such as BGA and flip-chip devices, it is important to produce good quality real-time X-ray images to isolate dry joints, bridging/shorts, voiding, misplacement / misalignment problems down to few microns or less resolution.

A high resolution camera is used in conjunction with high geometric magnification in order to keep a compact system that includes moving stages.
The same kind of set up can be used for inspection of the latest ceramic, plastic and composite structures as well.

The cameras required for this kind of routine exposure time of < 500ms per frame and good enough resolution: typically better than 25 microns minimum feature detection capability in order to keep the geometric magnification requirements.

This keeps the overall instrument dimensions as low as possible. Simultaneous read out and exposure cycles are usually necessary for keeping duty cycle as close as possible to 100%, thus enabling higher board inspection throughput.

Industrial PCB X-ray inspection / Digital X-ray radiography

Industrial PCB X-ray Inspection / Digital X-ray Radiography,

Digital X-ray Radiography Recommend products:

X-ray VHR camera X-ray FDI camera X-ray XEM camera

Ask an expert

High Energy Non Destructive Testing / Gamma Imaging

High Energy Non Destructive Testing from 225keV up to >1 MeV, a new approach to industrial scanning requiring high resolution and high sensitivity.

The use of high energy X-rays has applications in the fields of security, nuclear industry, oil and gas exploration as well as material / chemical science industries.

The detectors can provide multiple energy selection when used with a suitable scintillator / geometry. This can produce a “color” profile from multiple X-ray photon energies up to MeVs.

The detector allows to change from one dimensional scanning to two dimensional imaging geometries, depending on the energy used / dose / resolution sought. Active areas up to 450x225mm with 245 microns pixel size are available.

Gamma imaging is a particular case. We can supply special gamma cameras for detecting / imaging nuclear residues when decommissioning specific areas in nuclear plants.

Gamma cameras with state of art line collimators are also offered for high resolution drum inspection with increased sensitivity at 1.3MeV.

X-ray NDT Imaging - High energy Non Destructive Testing / gamma imaging

High Energy Non Destructive Testing / Gamma Imaging

X-ray NDT Imaging Recommend products:

X-ray Gemstar camera X-ray XEM camera

Ask an expert

X-ray Angiography / Fluoroscopy

X-ray Angiography is performed to specifically image and diagnose diseases of the blood vessels of the body, including the brain and heart.

Traditionally, Angiography was used to diagnose pathology of vessels suffering from blockage caused by plaque build up.

However in recent decades, radiologists, cardiologists and vascular surgeons have used the X-ray Angiography procedure to guide minimally invasive surgery of the blood vessels and arteries of the heart.

The detector must deliver good enough spatial resolution, contrast and be sensitive enough in order to minimize the dose incurred by both patients and surgeons.

Recent trials have shown that it is possible to decrease the instrumental noise equivalent exposure down to less than 0.1 microrad.

This new technology should provide improvements over current flat-panel detectors for applications such as fluoroscopy and angiography.

This requires high frame rates, good spatial resolution, dynamic range and sensitivity while maintaining essentially no lag and very low instrumental noise equivalent exposure.

X-ray angiography

X-ray Angiography / Fluoroscopy

Recommend products:

X-ray XEM array

Ask an expert

X-ray Gated Respiratory, Small Animal X-ray Imaging

X-ray Gated Respiratory experiments allows to refine Small Animal models / cardiac drug monitoring.

Cardiopulmonary imaging using Micro-Computed Tomography (CT) is a challenging task due to both cardiac and pulmonary motion and the limited fluence rate available from micro- focus X-ray tubes.

Successful imaging in mice requires recognition of both the spatial and temporal scales. The geometry must be optimized to match focal spot blur with detector pitch and the resolution limits imposed by the reproducibility of gating.

Motion is minimized for any single projection with 10 ms exposures that are synchronized to both cardiac and breathing motion.

High resolution detectors with good shuttering capability, fast read out and good dynamic range are the preferred solution for this type of application. Typical input size of 90x60mm matching the animal size with about 50 microns resolution FWHM and > 10,000:1 dynamic range is a good work horse solution that can be operated at up to 10fps on a optimized region of interest.

Synchronized acquisition using two detectors would allow stereoscopic acquisition without compromising acquisition speed.

X-ray Gated respiratory, small animal X-ray imaging

X-ray Gated Respiratory, Small Animal X-ray Imaging

Recommend products:

X-ray VHR camera

Ask an expert

X-RAY cameras X-RAY phase contrast micro and nano tomography X-RAY NDT Imaging

X-RAY phase contrast micro tomography nano tomography : X-RAY NDT Imaging. Photonic Science X-ray cameras and scientific detectors.

Thema : x-ray phase contrast - micro tomography - nano tomography - X-ray NDT Imaging - X-Ray cameras

x-ray phase contrast

X-ray NDT Imaging

X-ray microscopy gamma camera

X-RAY cameras X-RAY phase contrast micro tomography and nano tomography X-RAY NDT Imaging


Photonic Science Limited - Micro and nano tomography - X-ray NDT Imaging - X-ray phase contrast cameras and Scientific detector systems