How can an inexpensive NeutronOptics Camera compete, and what more do you need ?
Try our ImageJ Barrel Distortion Correction macro and example image stack.
Choice of CCD/CMOS & Lens for Different Applications
Our cameras have two main uses; tomographic imaging and in-beam sample alignment. Cameras for radiography use large cooled detectors with big lenses, while alignment cameras are simpler. We use the same scintillators, mirrors and lenses as for the most expensive cameras, but reduce costs with fixed geometry, laser-cut welded or simple cast aluminium boxes and a large variety of commercial Sony CCD and CMOS detectors.400x300mm Cooled CMOS X-ray or Neutron Camera
This 400x300mm camera, constructed for the new Venus BL at SNS ORNL, uses a full-frame 36x24mm IMX455 CMOS detector with 9576x6388 16-bit pixels giving 50 micron optical resolution with a bright Nikon 50mm f/1.2 lens. It has high efficiency and low noise.By removing the horizontal extension, the FOV can be reduced to ~300x200mm, increasing both intensity and optical resolution. We recommend small FOVs for lower flux sources, but a larger 500x400mm camera is being constructed for the University of California.
The 400x300mm camera costs <€20K, ready to operate including the scintillators.
Extra lead shielding is recommended below and around the detector. See the user manual.
250x200mm Cooled CMOS X-ray or Neutron Camera
Our standard 250x200mm imaging cameras cost up to €10K complete with scintillators, and are better suited to lower flux sources, allowing exposures of up to 10 minutes with cooled 1" to full-frame cooled Sony CCD and CMOS detectors.Extra lead shielding is recommended below and around the detector. See the user manual.
For tomography, a precision sample turntable is needed to rotate the sample in increments of eg 0.5 degree between images. The Newport Micro-Controle URS turntables start at ~€2500, and integrate with our camera software using the SMC100PP controller.
Fast Neutron Radiography with our Cameras
Fast 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. Fast neutron scintillators use high density polypropylene PP as a source of knock-on protons, and NeutronOptics now offer RC-TriTec PP-ZnS scintillators. Sizes: 75x50mm, 125x100mm, 250x200mm, 310x310mm (smaller is more efficient).Extra lead shielding is recommended below and around the detector.
Small D-D and D-T neutron generators are a promising development for low-cost neutron radiography, though the fast 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 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. It is remarkable that images were obtained through massive 30 cm thick lead shielding and filtering to attenuate gamma background.
An Experts Meeting on Fast Neutron Radiography at FRM2 Munich in October 2019 summarises progress, and includes our paper on An Efficient Camera for Fast Neutrons.
Small Cooled X-ray or Neutron Imaging Cameras
This custom camera is based on our 1-CCD Laue camera, but uses a cooled CMOS detector for much faster read-out and higher resolution, while maintaining low noise for up to 10 minute exposures. The Field-Of-View (FOV) of up to 125x100mm depends on the choice of detector and lens. Otherwise, smaller camera boxes can be used with smaller lenses.An optional B4C/Pb neutron detector shield can be provided.
Rapid CMOS X-ray or Neutron Cameras
Up to 120 frames/sec can be obtained with this new IMX432 CMOS camera using >10m USB3.2 cables. This is interesting for high intensity sources, usually x-rays, where short exposures (~10ms) can be sufficient. You don't need cooling for short exposures, and this simplifies camera operation, since only USB power is used, with a single cable. The camera can also be supplied with the 20 fps square IMX533 detector for the same price, when higher resolution and dynamic range are required with a lower frame-rate. With x3 SharpCap hardware binning of the IMX533 detector, up to 100 frames/sec can be achieved for 1000x1000 14-bit pixels.
This fast detector can also be used for smaller Fields-of-View with the mini-iCam or macro cameras
Small CMOS neutron or x-ray alignment cameras
USB powered CMOS detectors can be used instead of our slim CCD, increasing resolution and frame rate.
C-windows (x-rays) or Al-windows (neutrons) are used.
Smaller 75x50mm compact cameras or 100x50mm
slim cameras may be more suitable for cramped sample environments.
A larger
125x125mm version or even a
simple 200x125mm guide tube monitoring camera are also available, with optional higher resolution detectors. Note that the detector can be off-centered to reduce camera depth.
The mini-iCam neutron or x-ray camera
The mini i-Cam is our smallest (and cheapest) x-ray or neutron camera, using the slim CCD. It is intended for the alignment of small beams and samples, with USB power and easily interchangeable x-ray and neutron scintillators. A CMOS version is capable of at least 25µ resolution and high frame-rates.
High Resolution Macro Neutron and X-ray Cameras
We offer two types of macro camera; the normal macro camera which uses a close-up 1:1 macro lens, and the tandem-macro camera, which uses a pair of normal lenses front-to-front, both focussed at infinity. Tandem macro cameras are claimed by PCO to be competitive in efficiency to fibre-optic bundles bonded directly to the chip, combining high efficiency with high resolution, but the FOV is small (~10mm diameter). The FOV of our normal 1:1 macro camera is equal to the size of the detector chip, up to 36x24mm for the full-frame IMX455. The FOV can be doubled to 2:1 or more by using object extension tubes.
The full-frame IMX455 1:1 Macro camera (left) offers optical resolution equal to the 3.76 µm pixel size of the CMOS chip, with a FOV of 36x24 mm. The FOV can be doubled using the scintillator extension, halving the resolution. The resolution and brightness is less than our Tandem Macro camera, with its FOV of only ~10 mm.
A 50µ grid can be imaged with 3.8µ CCD pixels to a resolution of <10µ, depending on the scintillator and collimation. The real resolution depends on the scintillator, and we recommend Ultrafine GadOx scintillators, or columnar CsI scintillators as an alternative to our standard CAWO OG2 scintillator.
The camera is shown with a carbon fibre x-ray window, which unscrews to change the scintillator; thin aluminium windows are used for neutrons. Focus locking is obtained by simply pulling the focus ring, with an option for remote focussing, using a manual control box or a USB connection.
For detectors less than full-frame, we can use less expensive micro-4/3 lenses, such as the 11x11mm IMX533 detector with a more compact APS-C macro lens.
For details, see the CMOS Macro Camera manual.
Efficient Tandem Macro Neutron & X-ray Cameras
In this Tandem Macro camera, a pair of 35mm f/0.95 tandem lenses is x8 brighter than our normal macro camera, with similar 1:1 resolution. Maximising intensity is important when thin scintillators are used for the highest resolution.
Since the FOV is necessarily small, we have chosen a smaller 11.3x11.3mm IMX533 detector, coupled with a pair of f/0.95 micro-4/3" lenses. Different focal lengths can be used, depending on the required magnification and intensity. For example, our normal macro camera could use a Tandem Macro option, with a 35mm f/1.2 imaging lens in front of the 100mm lens, to give a 3:1 macro image of our 50µ wire grid.
See our Tandem Macro Camera Manual.
The image on the right was obtained on the ILL NeXT D50 beamline from our Twin Nikkor 50mm 1:1 camera using a 10µ thick Gd2O2S:Tb/6LiF PSI/RC-TriTec scintillator with 6% of the light output of their 200µ scintillator. The inner circle shows that at least 25µ resolution was obtained for an exposure of only 3s with a neutron flux estimated to be ~5x10**7 n/cm2/s.
Gd2O2S is also a good x-ray scintillator. (Credits: Alessandro Tengattini & Lukas Helfen, ILL)
1-CCD Laue backscattering crystal alignment camera
We 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". A classic bench-top x-ray generator with a spot size of ~1mm and power of 30-50 kV and 30-50 mA is required. The photo shows the 120x100mm camera, but a compact 100x80mm camera in a 200x120x67.5mm thick box is also available at the same price.
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. A Si backscattered Laue pattern was obtained by Dr Dean Hudek at Brown University, and a
Sm2Fe17 pattern was obtained by Dr Léopold Diop and Prof W. Donner at the Technische Universität Darmstadt in only 2 minutes on a 1960's Philips generator (click to enlarge). For details, see the 1-CCD Laue camera manual
Want to use your own CCD or a custom camera ?
If you already have a CCD unit we can build a camera box for it to your own specifications, with or without scintillators and lenses. Our custom laser cut and welded aluminium boxes with B4C light-tight baffles and aluminium screws can be provided with a choice of front-end path lengths to suit the size of your CCD and the focal length of your lens. You simply bolt your CCD to the end of the main box, and swap front-ends and/or lenses to change your Field-of-View and resolution.
For example, a 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 a compact 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 build a camera to satisfy it.
(Click on the photos to enlarge them).
CYCLOPS - 16-CCD 360-degree Neutron Laue Camera
CYCLOPS is a very fast neutron Laue camera constructed for ILL Grenoble according to an ILL "Millenium Program" proposal. 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
Alan.Hewat@NeutronOptics.com.