ABSTRACT
Silicon carbide (SiC) detectors of an Ni/4H-SiC Schottky diode structure and with sensitive areas of 1-4 cm² were fabricated using high-quality lightly doped epitaxial 4H-SiC material, and were tested in the detection of alpha particles and pulsed X-rays/UV-light. A linear energy response to alpha particles ranging from 5.157 to 5.805 MeV was obtained. The detectors were proved to have a low dark current, a good energy resolution, and a high neutron/gamma discrimination for pulsed radiation, showing the advantages in charged particle detection and neutron detection in high-temperature and high-radiation environments.
ABSTRACT
In the present work, the SnF2 powder was modified by silane coupling agent KBM403. The Fourier transform infrared spectrum (FTIR) of the modified powder showed that KBM403 was absorbed on the surface of SnF2 particles through physical absorption besides a weak chemical absorption. Then the SnF2 powder was modified by the solution dissolved with stilbene 3. The modified SnF2 powder could improve the decentralization of stilbene 3 dopant. An organic-inorganic hybrid luminescence glass was prepared by doping the modified SnF2 powder with stilbene 3 into the low melting lead-tin-fluorophosphate (PTFP) glass. The excitation, emission and transmission (absorption) spectra were used to characterize the hybrid glass. The results showed that introducing KBM403 could improve solubility and decentralization of stilbene 3 in PTFP glass, reduce the concentration of stilbene 3 dimers, and increase the transparency and homogeneity of the glass. Meanwhile, the luminescence intensity of stilbene 3 in this hybrid glass increased evidently compared with that of the stilbene 3 doped glass. The effect was assumed to be the reduction of the quenching of luminescence from stilbene 3 dimer and the enhancement of the rigidity of stilbene 3 molecules due to the interaction between KBM403 and stilbene 3.
ABSTRACT
Lead-tin-fluorophosphate (PTFP) glasses with different concentrations of organic dye stilbene 3 were prepared by low temperature melting. The molecular aggregation and spectrum properties of stilbene 3 doped lead-tin-fluorophosphate glass were studied by means of emission spectra, excitation spectra and absorption spectra measurements. The results show that stilbene 3 dimers coexist with its monomers in inorganic glass. Compared with the excitation peak of stilbene 3 monomer, the excitation peak of stilbene 3 dimer is in the range of shorter wave band. As the concentration of stilbene 3 in the doped PTFP glass increased, the emission peak was red shifted and the concentration quenching of stilbene 3 was observed in the emission spectra. Compared stilbene 3 in PTFP glass with that in ethanol, a remarkable red shift of the absorption and emission spectra in the glass was found. The phenomenon is explained by the bond effect between stilbene 3 and matrix glass by hydrophilic interaction. And a much higher fluorescence intensity of stilbene 3 in the inorganic glass than that in ethonal is attributed to the "cage" effect.
