How can an inexpensive NeutronOptics Camera compete with more expensive detectors?
All cameras can be supplied with either high efficiency x-ray or neutron scintillators.
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Tomography with NeutronOptics CamerasTomography requires the collection of radiographs with the sample rotated in the beam; specialised software is then used to reconstruct 3D images of the object and its interior. Both our standard high resolution imaging software, and our latest ImageJ-for-ASCOM software can collect hundreds of images, automatically, calling other Windows routines after each image to reset the sample position using eg LabView. Simple scripts link image acquisition, sample orientation and sophisticated image display with ImageJ.
All our cameras aquire images in 16-bit greyscale FITS format, and can create TIFF stacks of sequential projections. Both FITS and TIFF image formats can be read by imageJ and other applications such as MATLAB or OCTOPUS for tomographic reconstruction. But first read one of the free on-line books such as Principles of Computerized Tomographic Imaging and The Scientist Digital Signal Processing.
Fast Neutron Radiography with NeutronOptics CamerasAt the University ot Florida, one of our 200x200mm cameras has been used with an AdelphiTech 2.45 MeV neutron generator to obtain radiographs of large objects using only the normal 0.45mm 6LiF/ZnS thermal neutron scintillator. Scintillation in ZnS was apparently produced by knock-on protons rather than 6Li fission, and long exposures were needed because such a thin scintillator does not stop many fast neutrons, though high resolution can be obtained. Fast neutron imaging, especially using compact neutron generators, has important security screening applications.
Other clients from PSI Switzerland and the Hungarian Academy of Science have recently used one of our cameras for fast neutron radiography and tomography at the 10 MW Hungarian reactor, using an 8 mm thick BC400 transparent plastic scintillator with spatial resolution of around 1.3 mm. Again knock-on protons produced the scintillation. It is remarkable that images were obtained through massive 30 cm thick lead shielding and filtering to attenuate gamma background.
High Resolution Macro ImagingMost of our neutron cameras are designed with a nominal resolution of ~100µ, because in practice resolution is determined by beam collimation and scintillator thickness, not by camera optics. With x-ray imaging, much higher beam collimation is possible, especially with synchrotrons, and the flux is orders of magnitude greater, so very thin YAG:Ce or LuAG:Ce single crystal scintillators can be used. There is some progress in producing higher resolution neutron scintillators, but the neutron microscope is still not comparable to an x-ray microscope and certainly not to an electron microscope. A good summary of a simple macro neutron camera using commercial macro lenses is given by Kardjilov.
Even our standard 300x200mm cameras with our 37x27mm Kodak KAI-11002 interline CCD, which has an nominal resolution of 70µ, would be capable of a nominal 35µ resolution over 150x100mm if our usual 50mm f/1.2 NIKKOR lens was replaced by the Micro-NIKKOR 105mm f/2.8 and the latest Gd2O2S:Tb/6LiF 35µ scintillators now available from RC-TriTec.
Custom 110x100mm Compact CameraA 110x100mm Field-of-View was required with the smallest possible high-resolution camera embedded in shielding behind a pressure cell on the ISIS pulsed source.
We designed a camera using an uncooled 1392x1040 pixel Sony ICX825ALA CCD in the compact "Infinity" housing. Full-frame readout is only 0.5s and multiple exposures can be stacked in real-time to build up an image of the sample in a strongly absorbing environment.
Tell us your specific requirement and we will design and build a camera to fulfill it.
Fast 250x200mm X-ray or Neutron Imaging CameraOur latest camera has exceptionally low noise, high resolution and fast readout over large areas. We use the new 1 inch Sony ICX694ALG EXview HAD CCD II to give a resolution of 2750x2200 pixels over an area of 250x200mm (90 µm resolution). Dark current is virtually eliminated by thermo-electric cooling by -35C, and high speed readout noise is low. The total noise count in 300s over 6 million pixels is only ~2000 counts, and that can be reduced to ~500 with the isolated hot pixel filter of imageJ. That is amazingly low, resulting in exceptional dynamic range. The 180mm long front section can easily be removed to change between different neutron and x-ray scintillators. (Detailed Manual)
- Sensor: 1" Sony EXview HAD CCD II
- Optics: High resolution f/1.4 1" lens
- Resolution: 2750 x 2200 pixels
- High sensitivity: (QE~75%), low smear
- Dark current: 0.002 e/pix/s @-10 °C
- Cooling: Regulated Peltier ΔT = -35°C
- Digital Output: 16-bit 65536 levels
- Readout Speed: 6-12 MPixels/s
- Binning and Region-of-Interest
- External Trigger: GPIO synchronisation
- SDK: C++, VB, .net, ImageJ, LabView
(Click on the photos to enlarge them)
Other CCD units and lenses can be used with this camera box, by simply changing the length of the front-end section to obtain the desired Field-of-View. For example the Nikkor 50mm f/1.2 lens can be used with the 4/3" 2048x2048 pixel KAI04022 CCD, or the very large 35mm 4008x2672 pixel KAI11002 CCD for highest efficiency and resolution.
Big 400x300mm X-ray or Neutron Imaging CameraOur biggest camera manufactured to date uses the 37x27mm Kodak KAI-11002 interline CCD with 4008x2672 pixels giving a resolution of ~100 µm over an area of 400x300mm. As usual, the scintillator is in the 200mm interchangeable front section, and the main camera body can accommodate other CCD units and lenses, with the length of the front section adjusted to obtain the desired Field-of-View with the chosen CCD.
A 400x400mm camera could be made with the even larger 36x36mm APS Kodak KAF-16803 full frame CCD with 4096x4096 pixels. This would have similar sensitivity and resolution to our popular 200x200mm camera, but with x4 the area !
- Sensor: 35mm Kodak KAI11002
- Optics: Nikkor f/1.2 50mm lens
- Resolution: 4008 x 2672 pixels
- High sensitivity: (QE~50%)
- Dark current: <0.03 at -20 °C
- Cooling: Regulated ΔT = -38°C
- Digital Output: 16-bit 65536 levels
- Readout Speed: 1 MPixels/s
- Binning and Region-of-Interest
- Software Trigger
- SDK: C++, VB, .net, ImageJ, LabView
Click the photos to enlarge them.
Note the pencil for scale.
Extended 250x200mm Camera for Radioactive SamplesRadioactive samples require special precautions to avoid damage to the CCD. Our solution is to use a telephoto lens to increase the optical path, so that the CCD section can be housed in a blockhouse several meters from the active sample, which can then be close to the scintillator to obtain the best resolution. This extended L-shaped camera is a stretched version of our 250x200mm "fast" camera. Relatively inexpensive 200mm or 100mm Canon or Nikon lenses are used, though these lenses with f/2.0 or f/2.8 are not as bright as our usual f/1.2 or f/1.4 lenses; an f/1.4 lens is x4 as efficient as an f/2.8 lens, but this camera is still fast enough for tomography on a low flux Triga reactor.
Our "extended" camera has up to three 1000mm long front segments with an 800mm high vertical section holding the CCD, lens and mirror to give a maximum optical path of 3800mm, and a minimum of 800mm. Standard Canon or Nikon lens mounts are used, so it is easy to change the lens as well as the optical path.
(Click on the photos to enlarge).
Laue crystal alignment camerasWe have developed various Laue crystal alignment cameras for x-rays to replace the old Polaroid Laue camera, and similar cameras might be used with a neutron beam. A finely collimated white beam produces a number of "Bragg spots" from a single crystal, and by measuring the positions of these spots the crystal orientation can be determined. Greater precision is obtained with backscattering, but the intensities are much weaker, especially for x-rays because of the scattering "form-factor".
We have recently developed this single CCD backscattering camera, where a fine collimator in the back of the camera directs the beam through a small hole in a mirror and out through the front carbon fibre window. The backscattered diffraction pattern from a single crystal a few cm in front of the window is captured on a scintillator behind the window, and this pattern is reflected by the mirror to the lens-coupled CCD on top.
The slim 100x50 mm neutron or x-ray cameraOur popular slim camera is only 44mm thick for a sensitive area of 100x50mm in a 120x120mm box. It can fit into the small space between the sample environment and the beam stop, no power is required except for a single 10m USB2 cable for control and image acquisition, and it is very efficient. And if you drop it it is easy to repair , since all parts can be replaced.
The mini-iCam 36 mm neutron or x-ray camera
The mini i-Cam is our smallest (and cheapest) x-ray or neutron camera, and uses the slim CCD. It is intended for the alignment of small beams and samples, for example, behind our backscattering Laue camera. It is powered by the USB2 data cable, so is very simple to set up and use.
The i-Cam is only ~160mm long and has 580 or 1040 pixel resolution over an area of 36mm diameter, so with its efficient f/1.0 lens it is also very bright. The scintillator and carbon fibre window can easily be exchanged, depending on whether x-rays or neutrons are to be imaged. A Pb-glass plate protects the CCD from radiation damage.
The mini-iCam can otherwise be supplied with a 90-degree mirror in front of the lens, with the camera perpendicular to the beam, so the Pb-glass plate is no longer needed. The in-beam length is then only 50mm for an image of 35mm diameter through the carbon fibre window. Details may differ slightly from the photo opposite.
Imaging with NeutronOptics high resolution cameras
Click to enlarge the images, which are highly compressed for the WWW.
a) High resolution 10s neutron image of an invisible crack in an ancient vase from the 1.3MW Triga reactor at the Thai Institute for Nuclear Technology (Dr. K Sasiphan, TINT)
b) High resolution x-ray images of thick objects (a valve and batteries) from only fifty
50-nanosecond pulses from a Golden Eng. 350 kVp pulsed portable x-ray generator
(Prof. Jeffrey King, Colorado School of Mines)
These applications use our advanced imaging camera with either neutron or x-ray scintillators and windows.
an inexpensive stepper rotation table (not tested) these cameras might be used for tomographic imaging.
High Efficiency Photonic Science neutron cameras
CYCLOPS is the latest and largest PhotonicScience neutron camera constructed for ILL. It consists of 16 image-intensified Peltier-cooled CCDs scanning an octagonal scintillator to cover almost complete 4π scattering in real time. Total readout time is only ~1 sec for the complete 7680x2400 array of 170µ pixels as an 8, 12 or 16-bit TIF image. A complete diffraction pattern can be obtained in only a few seconds, making it possible to follow changes in crystal structure as a function of temperature, pressure or magnetic field. Here is a short streaming video illustrating the astonishing power of such a machine, even if at present it is located on a low-flux guide with a 107.n.cm-2.sec-1 white thermal beam.
All these cameras use a white neutron beam, and will work on either reactor or spallation neutron sources.
For further details of their application and availability, please contact