A double-sided silicon strip detector(DSSD)with active area of 48 mm x 48 mm and thickness of300μm has been developed. Each side of DSSD consists of48 strips, each with width of 0.9 mm and inter-strip separation of 0...A double-sided silicon strip detector(DSSD)with active area of 48 mm x 48 mm and thickness of300μm has been developed. Each side of DSSD consists of48 strips, each with width of 0.9 mm and inter-strip separation of 0.1 mm. Electrical properties and detection performances including full depletion bias voltage, reverse leakage current, rise time, energy resolution and cross talk have been studied. At a bias of 80 V, leakage current in each strip is less than 15 nA, and rise time for alpha particle at 5157 keV is approximately 15 ns on both sides.Good energy resolutions have been achieved with0.65-0.80% for the junction strips and 0.85-1.00% for the ohmic strips. The cross talk is found to be negligible on both sides. The overall good performance of DSSD indicates its readiness for various nuclear physics experiments.展开更多
The thermodyntamics of axial coordination reaction of Cobalt(Ⅱ)(pOCH3)TPP with various ligands [L=Im(imidazole), MeIm (2-methydrimidazole), EMIm (2-ethyl-4-methylimidazole)] at different temperatures in dichlorometha...The thermodyntamics of axial coordination reaction of Cobalt(Ⅱ)(pOCH3)TPP with various ligands [L=Im(imidazole), MeIm (2-methydrimidazole), EMIm (2-ethyl-4-methylimidazole)] at different temperatures in dichloromethane solvent have been studied. The equilibrium constant (β) and stoichiometric numer (n) of reaction (1) were measured by means of Shimadzu UV-240 spectrophotometer. The changes of standard molar enthalpy △ rH and molar entropy △ S of reaction (1) were calculated. The steric and electroaic effects of the three axial ligands on the reaction were compared. The kinetic study for the talal coordination faster reaction of Cobalt(Ⅱ) (pOCH3)TPP with Im in dichloromethane at dtherent temperatures by means of a Uuion Giken RA-401 stopped-flow spectrophotometer was reported. The mechanism of reaction (1) was postulated as follows:The parameters K and k were evaluated. The △ H △ S of a pre-equllibrium step (2) and △ Hm, △ Sm of a rate-determihing step (3) were also calculated.展开更多
Using positive surface charge instead of traditional γ-ray total dose irradiation, the electric field distribution of a P-channel VDMOS terminal has been analyzed. A novel terminal structure for improving the total d...Using positive surface charge instead of traditional γ-ray total dose irradiation, the electric field distribution of a P-channel VDMOS terminal has been analyzed. A novel terminal structure for improving the total dose irradiation hardened of P-channel VDMOS has been proposed, and the structure is simulated and demonstrated with a -150 V P-channel VDMOS. The results show that the peak current density is reduced from 5.51 × 10^3 A/cm^2 to 2.01 × 10^3 A/cm^2, and the changed value of the breakdown voltage is 2.5 V at 500 krad（Si）. Especially, using 60Co and X-ray to validate the results, which strictly match with the simulated values, there is not any added mask or process to fabricate the novel structure, of which the process is compatible with common P-channel VDMOS processes. The novel terminal structure can be widely used in total irradiation hardened P-channel VDMOS design and fabrication, which holds a great potential application in the space irradiation environment.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U1432246,U1632136,U1432127,11375268,11635015,and 11475263)the National Basic Research Program of China(No.2013CB834404)
文摘A double-sided silicon strip detector(DSSD)with active area of 48 mm x 48 mm and thickness of300μm has been developed. Each side of DSSD consists of48 strips, each with width of 0.9 mm and inter-strip separation of 0.1 mm. Electrical properties and detection performances including full depletion bias voltage, reverse leakage current, rise time, energy resolution and cross talk have been studied. At a bias of 80 V, leakage current in each strip is less than 15 nA, and rise time for alpha particle at 5157 keV is approximately 15 ns on both sides.Good energy resolutions have been achieved with0.65-0.80% for the junction strips and 0.85-1.00% for the ohmic strips. The cross talk is found to be negligible on both sides. The overall good performance of DSSD indicates its readiness for various nuclear physics experiments.
文摘The thermodyntamics of axial coordination reaction of Cobalt(Ⅱ)(pOCH3)TPP with various ligands [L=Im(imidazole), MeIm (2-methydrimidazole), EMIm (2-ethyl-4-methylimidazole)] at different temperatures in dichloromethane solvent have been studied. The equilibrium constant (β) and stoichiometric numer (n) of reaction (1) were measured by means of Shimadzu UV-240 spectrophotometer. The changes of standard molar enthalpy △ rH and molar entropy △ S of reaction (1) were calculated. The steric and electroaic effects of the three axial ligands on the reaction were compared. The kinetic study for the talal coordination faster reaction of Cobalt(Ⅱ) (pOCH3)TPP with Im in dichloromethane at dtherent temperatures by means of a Uuion Giken RA-401 stopped-flow spectrophotometer was reported. The mechanism of reaction (1) was postulated as follows:The parameters K and k were evaluated. The △ H △ S of a pre-equllibrium step (2) and △ Hm, △ Sm of a rate-determihing step (3) were also calculated.
基金supported by the Pre-Research Foundation(No.51311050202)
文摘Using positive surface charge instead of traditional γ-ray total dose irradiation, the electric field distribution of a P-channel VDMOS terminal has been analyzed. A novel terminal structure for improving the total dose irradiation hardened of P-channel VDMOS has been proposed, and the structure is simulated and demonstrated with a -150 V P-channel VDMOS. The results show that the peak current density is reduced from 5.51 × 10^3 A/cm^2 to 2.01 × 10^3 A/cm^2, and the changed value of the breakdown voltage is 2.5 V at 500 krad（Si）. Especially, using 60Co and X-ray to validate the results, which strictly match with the simulated values, there is not any added mask or process to fabricate the novel structure, of which the process is compatible with common P-channel VDMOS processes. The novel terminal structure can be widely used in total irradiation hardened P-channel VDMOS design and fabrication, which holds a great potential application in the space irradiation environment.
