Background Fast neutron detection is meaningful in many research fields such as space environment monitoring.A scintillating fiber array model for fast neutron detection was proposed and developed in 1980s.Aerospace applications of the model require electronics in small size.Purpose To design a dedicated electronic system to readout and process the 384-channel signals from scintillating fiber array,and to use the designed system to fabricate a neutron detector for aerospace applications.Methods With the method of nuclear recoil,fast neutron is detected by tracking recoil proton of n–p scatter in scintillating plastic fibers.Using the peak-holding circuits and multiplexers,the system size and power consumption were reduced.Results The detector fabricated with the designed system,had 34 cm×34 cm×27 cm mechanical size,20.4 kg weight,and 30.05W power consumption.Comparing to traditional waveform sampling electronics,the designed electronics was highly integrated and had a small size.The readout electronics also gave a better energy resolution of 39%in neutron detection,while the energy resolution was 43%in previous version.Conclusion In this study,a highly integrated readout electronic system was designed and verified.The detector using the system gave good performance.The designed electronics had potential development in fast neutron detection and other high energy physics detection system.
This study fully investigated the vacuum ultraviolet excitation spectra of pure and rare-earth(RE=Eu, Tb and Dy)-doped A2Zr(PO4)2(A=Li, Na and K) phosphors. The synthesized Na and Li compounds were characterized by XRD showing two new types of phases after indexation. Although these three pure compounds had different crystal structures, they exhibited similar luminescence properties. For Eu3+-activated samples, the broad excitation band centered at 217 nm could be attributed to the CT transition between O2–(2p6) and Eu3+ ions. For Tb3+-doped samples, two groups of f-d transitions were observed, where a strong broad band at 221 nm was due to the spin-allowed f-d transition. Energy transfer from O2– to Dy3+was not observed in Dy3+-doped phosphors, probably because it overlapped considerably with the CT transition from O2– to Zr4+ at 187 nm.
Thallium-doped cesium iodide(Cs I(Tl)) screens are widely used in X-ray imaging devices because of the columnar structure of the Cs I(Tl) layer, but few reports focus on the optical role of the substrate in the screen system.In this paper, four substrates including fused silica(Si O2), silver-film coated Si O2, graphite(C) and fiber optic plate(FOP) are used to fabricate Cs I(Tl) screens by thermal evaporation. Their imaging performance is evaluated by relative light output(RLO), modulation transfer function(MTF), normalized noise power spectrum(NNPS) and noise equivalent quanta(NEQ). The results reveal that although Cs I(Tl) film on graphite plate yields images with the lowest light output, it presents relatively higher spatial resolution and better signal-to-noise characteristics.However, films on Si O2 plate obtain low MTF but high NNPS curves, whether they are coated with silver film or not.Furthermore, scintillation screens on FOP have bright images with low NNPS and high NEQ, but have the lowest MTF. By controlling the substrate optical features, Cs I(Tl) films can be tailored to suit a given application.
