Development of a New High-Frame-Rate Camera for Pulsed Neutron Transmission Spectroscopic Radiography

Abstract

Pulsed neutron transmission spectroscopic radiography is an attractive new technique in energy-resolved neutron radiography. The imaging technique is based on the spectral analysis of neutrons through the time-of-flight (TOF) method. The neutron transmission spectrum that can be obtained using a time-resolved neutron imaging system includes the Bragg-scattering edges with crystallographic information and the transmission dips due to the resonance absorption of the nuclei. To obtain the neutron transmission spectrum with high-power neutron sources, we developed a new high-performance imaging system consisting of a neutron color image intensifier, photon image intensifier, high-resolution CMOS camera, and high-frame-rate camera. The system was used for experiments at the electron linac pulsed neutron source in Hokkaido University, and the targeted function was proved to be successful.

Improvement of Neutron Color Image Intensifier Detector using an Industrial Digital Camera

“…For example, if neutron transmission images can be continuously taken with a moving average of 1 second at 30 fps under the flux of 3x10 6 n/cm 2 /sec as typical small reactors, it would take as much as 1000 seconds (17 minutes) under flux 3x10 3 n/cm 2 /sec to get the similar brightness single frame image, and 10000 seconds (2.8 hours) under flux 3x10 2 n/cm 2 /sec as neutron generators, respectively. Cameras installed in the previous NII systems were video cameras, high-definition digital single-lens reflex cameras or high-speed cameras [3,4]. In case of exposing with 17 minutes or 2.8 hours in the single lens reflex camera, bulb shooting will be performed during that time.…”

“…The emitted electrons are accelerated by the electric field toward the phosphor luminescent window while maintaining the neutron incident image. For the neutron detection by the image intensifier some developments were necessary in the input and output windows with short decay time to apply to pulsed neutron sources [3,4]. As the imaging system the NII is combined with an optical system which consists of a lens and a camera.…”

High-Definition Pulsed Neutron Imaging with High-Frame-Rate Camera Using Center-of-Gravity and Super-Resolution Processing for Bright Spots from Image Intensifier

“…Recently, time-resolved neutron imaging using a pulsed neutron source has attracted attention [1][2][3], and large and small pulsed neutron sources have been developed. Further, for time-resolved neutron imaging, detectors using high-frame-rate cameras have also been developed, which use image intensifiers (IIs) to amplify scintillation light [4]. However, using IIs deteriorates spatial resolution.…”

Evaluation of High-frame-rate Camera with Digital Accumulation System Combined with Neutron Color Image Intensifier for Energy Resolved Neutron Imaging

“…This detector cannot be used for time-resolved imaging, but it can manage very intense neutron beams. An integral-type high-frame-rate camera was developed [7] as another type of a camera detector. This paper reports the performance of this integral-type camera detector at RADEN and presents the results of a feasibility study regarding this camera's neutron counting technique.…”