DETECTOR PRODUCTS
Sealed Image Intensified Neutron Detectors
The basic building block of NOVA 's neutron detectors is comprised of a highly sensitive microchannel Plate (MCP) sealed within a ruggedized vacuum assembly, using the same strict performance criteria found in military night vision imaging systems. Our specialized, neutron-sensitive MCPs are vacuum baked and electron scrubbed and assembled with an aluminum or sapphire front window and precisely aligned to a high quality phosphor output window. The tube is then potted, tested for electrical performance, and evaluated in neutron radiation to meet stringent quality control standards of uniformity and sensitivity.
Typically the sealed neutron detectors have a single MCP plate, which provides a gain of approximately 1000x for each neutron captured (e.g. each neutron detected creates a 1 nanosecond pulse of ~1000 electrons. For applications where the neutron flux is low, as is the case in many university research reactors, two (Chevron configuration) or three (Z-stack configuration) MCPs are ganged together to provide several orders of magnitude higher electron gain. Schematically this configuration is shown below. A small DC power supply provides the necessary bias voltages to operate the tube.
The individual channels of the MCP are typically 6 microns, so the intensifier will provide radiographic imaging resolution below 50 µm when the phantom is placed at or near the front surface of the window, with the minimum resolution dependent upon the divergence of the neutron beam. The phosphor screen can be viewed by eye or recorded using an electronic camera for post processing. Presently NOVA offers 18 mm and 25 mm diameter image intensifiers as standard formats. Please contact us for price and delivery.
Image Intensifiers Optically Coupled To A CCD/CID Camera
Our integrated neutron detection system optically couples the high-efficiency image intensifier to a CCD camera or a radiation-hardened Charge Injection Device (CID) camera readout with a fiberoptic window or taper. The neutron images can be observed in real-time, or can be electronically archived with the associated computer hardware.
CID cameras are radiation resistant, allowing them to operate in the mixed radiation around neutron source environments. These unique cameras permit exceptional low noise imaging as compared to CCD cameras, but are considerably more expensive.
The assembly is packaged for ease of use by the operator, whether using it as a portable device or as part of fixed experiment, with the necessary electronics integrated. The compact size allows use in tight or confining areas. NOVA can also supply associated frame grabbers, computers, and basic post-processing software to archive the signals and further enhance the resolution.
Customized Neutron Imaging Systems
NOVA also provides highly customized systems targeted to specific applications and neutron beam characteristics. These systems can combine a large area phosphor screen for expanded viewing at lower resolution, and high-resolution detailing can be carried out by exchanging the phosphor screen position with the sealed image intensifier. This permits the researcher to effectively zoom the system for fine detail imaging. Both are viewed with a lens coupled, image intensified CID camera looking at a 99%+ reflective front surface mirror. Gain can be adjusted as needed for radiographic imaging of weak signals, or low contrast materials. The figure below shows schematically the layout of the detection system.
For more information, please contact NOVA
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