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Targeting improved spatial resolution, a three-dimensional positron-emission-tomography (PET) scanner employing CdTe semiconductor detectors and using depth-of-interaction (DOI) information was developed, and its physical performance was evaluated. This PET scanner is the first to use semiconductor detectors dedicated to the human brain and head-and-neck region. Imaging performance of the scanner used for ^18F-fluorodeoxy glucose (FDG) scans of phantoms and human brains was evaluated. The gantry of the scanner has a 35.0-cm-diameter patient port, the trans-axial field of view (FOV) is 31.0 cm, and the axial FOV is 24.6 cm. The energy resolution averaged over all detector channels and timing resolution were 4.1% and 6.8 ns (each in FWHM), respectively. Spatial resolution measured at the center of FOV was 2.3-mm FWHM—which is one of the best resolutions achieved by human PET scanners. Noise-equivalent count ratio (NEC2R) has a maximum in the energy window of 390 to 540 keV and is 36 kcps/Bq/cm^3 at 3.7 kBq/cm^3. The sensitivity of the system according to NEMA 1994 was 25.9 cps/Bq/cm^3. Scatter fraction of the scanner is 37% for the energy window of 390 to 540 keV and 23% for 450 to 540 keV. Images of a hot-rod phantom and images of brain glucose metabolism show that the structural accuracy of the images obtained with the semiconductor PET scanner is higher than that possible with a conventional Bismuth Germanium Oxide (BGO) PET scanner. In addition, the developed scanner permits better delineation of the head-and-neck cancer. These results show that the semiconductor PET scanner will play a major role in the upcoming era of personalized medicine. [ABSTRACT FROM AUTHOR]

We are developing a fiber type two-dimentional (2-D) position-sensitive detector having a spatial resolution less than 0.5 mm in order to use it in the time-of-flight (TOF) measurement. The detector performance was examined, and some experiments on the TOF radiography were performed using this detector. The results indicated that the detector could be applied successfully to the TOF measurement and that the TOF radiography was very useful since it gave more informative data than those obtained by the conventional radiography using a broad energy band. [ABSTRACT FROM AUTHOR]

Reports on the application of a scintillator-based area detector to the neutron time-of-flight method by developing an electronics system for the detector. Spatial resolution which was consistent with a fiber width of 0.4 millimeter; Detection efficiency for thermal neutrons.

The sharp variation of neutron attenuation at certain energies specific to particular nuclides (the lower range being from ~1eV up to ~1keV), can be exploited for the remote mapping of element and/or isotope distributions, as well as temperature probing, within relatively thick samples. Intense pulsed neutron beam-lines at spallation sources combined with a high spatial, high-timing resolution neutron counting detector, provide a unique opportunity to measure neutron transmission spectra through the time-of-flight technique. We present the results of experiments where spatially resolved neutron resonances were measured, at energies up to 50keV. These experiments were performed with the intense flux low background NOBORU neutron beamline at the J-PARC neutron source and the high timing resolution (~20ns at epithermal neutron energies) and spatial resolution (~55µm) neutron counting detector using microchannel plates coupled to a Timepix electronic readout. Simultaneous element-specific imaging was carried out for several materials, at a spatial resolution of ~150µm. The high timing resolution of our detector combined with the low background beamline, also enabled characterization of the neutron pulse itself – specifically its pulse width, which varies with neutron energy. The results of our measurements are in good agreement with the predicted results for the double pulse structure of the J-PARC facility, which provides two 100ns-wide proton pulses separated by 600ns, broadened by the neutron energy moderation process. Thermal neutron radiography can be conducted simultaneously with resonance transmission spectroscopy, and can reveal the internal structure of the samples. The transmission spectra measured in our experiments demonstrate the feasibility of mapping elemental distributions using this non-destructive technique, for those elements (and in certain cases, specific isotopes), which have resonance energies below a few keV, and with lower resolution for elements with relatively high resonance energies in the 1–30keV range. [ABSTRACT FROM AUTHOR]

A readout electronics system for linear position sensitive 3He gas detectors has been developed. It is widely used for neutron scattering instruments at KEK Neutron Science Laboratory (KENS). The basic structure of the system is quite versatile, and can be used for various imaging-systems. Several versatile readout systems have been developed at KENS. As one of such examples, a 2-dimensional imaging-system for a wavelength shifting fiber based scintillation counter system has been developed. [Copyright &y& Elsevier]

For evaluating neutron optical devices, we have developed the two-dimensional position-sensitive neutron detectors (PSND) of the crossing fibre array type. In parallel, we have studied the PSNDs of the direct coupling type with flat panel photomultiplier tubes for responding to various spatial resolutions with high detection efficiency. This paper views and reports on the recent status of development of PSNDs based on neutron scintillators in neutron optics group. [Copyright &y& Elsevier]