How can an inexpensive NeutronOptics Camera compete, and what more do you need ?
All cameras are supplied with software & high efficiency x-ray or neutron scintillators.
Try our ImageJ Barrel Distortion Correction macro & example image stack.
Here are some notes on the kind of computer you can use.
Hot Neutron Radiography with our CamerasHot neutrons (2.45MeV or 14MeV) are very much harder to detect than thermal neutrons because they are not captured by nuclei to provide ionising fission fragments. Scintillation in ZnS can however be achieved with knock-on protons rather than 6Li fission, though long exposures are needed. Hot neutron scintillators use high density polypropylene PP as a source of knock-on protons, and NeutronOptics now offer RC-TriTec PP-ZnS scintillators. Standard sizes are 75x50mm, 125x100mm and 250x200mm (smaller is more efficient).
Small D-D and D-T neutron generators are a promising development for low-cost neutron radiography, though the hot neutron flux is low. Even so, one of our 250x200mm cameras has already been used with an AdelphiTech 2.45 MeV D-D neutron generator to obtain radiographs with long exposures (~10 min).
The efficiency of the camera can be increased by a factor of x4 by reducing the FOV to 125x100mm, and can be further increased by a factor of x64 by binning pixels 8x8. Since the resolution after binning the smaller FOV will still be 360µm, this is still sufficient with the 2.5mm PP scintillators used for fast neutrons. The smaller camera is shown above. A cheaper compact version is also available.
Other clients from ETH-Zurich, PSI Switzerland and the Hungarian Academy of Science have recently used our smaller TS14 camera for hot 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. It is remarkable that images were obtained through massive 30 cm thick lead shielding and filtering to attenuate gamma background.
1-CCD Laue backscattering crystal alignment cameraWe have developed various Laue crystal alignment cameras for x-rays, and similar cameras can be used with a neutron beam. They allow rapid crystal alignment, and can also be used for hands-on teaching of crystallography. 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 weaker, especially for x-rays because of the scattering "form-factor".
This inexpensive Sony 1" CCD backscattering camera is designed to replace the old Polaroid Laue camera, and has similar performance. A 1mm collimator traversing 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 30 mm 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 1mm inner collimator can be simply pulled out to obtain courser 2mm collimation. This Si backscattered Laue pattern was obtained by Dr Dean Hudek at Brown University. A Sm2Fe17 pattern was obtained by Dr Léopold Diop and Prof W. Donner at the Technische Universität Darmstadt in only 2 minutes (click to enlarge).
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 (13 MB) 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.
For tomography, a precision sample turntable is needed to rotate the sample in increments of eg 0.5 degree between images. For samples of up to 30 Kg, we recommend the Newport Micro-Controle URS turntables which start at ~€2500, together with the SMC100PP motor controller (~€650) and SMC-PS80 power supply (~€93) and SMC-USB USB interface(~€63).
Anders Kaestner at PSI has developed free tomography reconstruction software tools.
The partial 3D reconstruction of a clock shown opposite was obtained from FRM-2 ANTARES data provided by Burkhard Schillinger. ImageJ was used to reslice the full reconstructed XY stack to XZ slices which were then displayed by imageJ's 3D_Viewer (low resolution GIF sample).
Neutron & X-ray Imaging with NeutronOptics camerasThe NeutronOptics 250x200m with interchangeable scintillatrs can be used for both neutron and x-ray imaging with different contrast. (Click the photos to enlarge)
High Resolution Macro Imaging CamerasKardjilov has described a simple macro neutron camera using commercial large aperture macro lenses, and such lenses are an option for our imaging cameras. We have constructed an inexpensive 1:1 macro imaging camera designed to use the latest Gd2O2S:Tb high resolution neutron/x-ray scintillators now available from RC-TriTec. The photo shows our macro camera optics; without the CCD unit it is 290mm high. With a large f=100mm f/2.8 F-mount macro lens, the FOV is equal to the size of the CCD, and a 50µ grid can be imaged with 3.9µ CCD pixels to a resolution of <10µ (detail), though the real resolution will depend on the scintillator and collimation.
The camera is shown with a carbon fibre x-ray window, which unscrews to change the scintillator, but thin aluminium windows are supplied for neutrons. The C-mount adapter can be unscrewed to take Nikon F-mount cameras up to 35mm full frame. Fine manual focus locking is provided by a thumbscrew mechanism; optional remote focussing can be provided by a motorised drive, controlled either by a remote manual control box or via a USB computer connection.
Click the photo to enlarge it.
A compact version using a shorter focal length lens and lower magnification gives larger FOVs. A 75µ grid can be imaged to ~20µ pixels with a FOV of ~40mm with the Sony 1" ICX694ALG CCD. A 2x super resolution version can be made to order with an additional 50mm Rodenstock lens (Williams et al.)
The FLIR (Point Grey) IMX249 CMOS CameraNeutronOptics x-ray or neutron cameras can be supplied with an optional FLIR (Point Grey) IMX249 CMOS Camera when high frame rates are required (up to 41 fps). The maximum exposure of the IMX249 camera with USB3 is 4 seconds (30 seconds for the GigE version); dark current noise is higher for CMOS cameras, limiting them to shorter exposures.
The IMX249 is a slower frame-rate version of the IMX174, currently the best Sony CMOS detector for low-light imaging. It is a relatively large sensor, with big pixels favouring light capture, with high Quantum Efficiency (QE) The USB3 camera is powered by a 5m USB cable, and the GigE version by a powered GigE cable. Note the cooling fins added to the FLIR camera to limit temperature (and dark current), and the carbon fibre x-ray window.
- Sensor Type: Sony Pregius CMOS IMX249
- Image size: Diagonal 13 mm (Type 1/1.2")
- Resolution: 1920 x 1200
- Pixel Size: 5.86 x 5.86 µm
- High sensitivity: (QE~80% at 500-600nm)
- High dark current: (~1 e/s @ 45C)
- Full well capacity: >30,000 e- (high dynamic range)
- ADC: 12 bit grey scale, stretched to 16-bit
- Gain: 0 dB to 29.9 dB
- Readout Noise: ~7 e- (low readout noise in mode_7)
- Readout Time: ~0.025s (up to 41 fps full frame rates)*
- Interface: USB 3.1 High Speed with 5m USB cable
or PoE GigE ethernet for long distances
- Power: power over USB (or Ethernet)
- Maximum Exposure Length: 4s USB3, 30s GigE
- SDK: FLIR (Pt Grey) FlyCapture and Spinnaker C++ SDK
But rates of 9 fps can be obtained even with 10+ metre amplified USB2 extension cables.
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 with the cooled CCD is only ~1c/s/pixel (~300 counts in up to 65,536), resulting in excellent 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 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).
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