The work of the irradiation technique group of the material center is aimed at following two aspects:1. Technique support In 2015, we have had about 500 h beam time for 42 the single event effect (SEE) tests, which co...The work of the irradiation technique group of the material center is aimed at following two aspects:1. Technique support In 2015, we have had about 500 h beam time for 42 the single event effect (SEE) tests, which cooperating with various institutes, universities, and companies. The ground tests are the basic safeguard for the spacecraft and satellite. In order to raise the irradiation efficiency of the Terminal 5, an improvement of the sample transfer system has been accomplished. To study the dependency of SEE on the ion flux, a flip-flop composed of four kinds of structure test and analysis have been done. And some SEE simulation methods have been established.展开更多
A biaxial rotational technique is proposed to improve the neutron irradiation uniformity for a large sample,and the theoretical method is established to predict and design the main parameters. The technique used a dev...A biaxial rotational technique is proposed to improve the neutron irradiation uniformity for a large sample,and the theoretical method is established to predict and design the main parameters. The technique used a device to rotate the target sample around two perpendicular axes simultaneously. Numerical calculations found that the lowest common multiple of the two angular speeds should be large enough to improve the uniformity,and the minimal experimental time should be no less than 600 s. For a three-dimensional sample with a size of 20 cm × 12 cm × 14 cm, the maximal non-uniform neutron irradiation factor of the sample is mainly determined by the distance between the center of the sample and of the point neutron source. It was computed to be less than 10% when the distance was no less than 34 cm. Experiments were carried out on the CFBR-II reactor and the experimental results were in good accordance with the theoretical analysis. As a result, the theoretical conclusions given above are reasonable and of reference value for the design of future irradiation experiments.展开更多
70 MeV-carbon-ion irradiation is used to simulate the radiation swelling induced by neutron irradiation of 3.2 × 1022 n·cm-2 in domestically-made 316 austenitic stainless steels modified by a 20%-cold-workin...70 MeV-carbon-ion irradiation is used to simulate the radiation swelling induced by neutron irradiation of 3.2 × 1022 n·cm-2 in domestically-made 316 austenitic stainless steels modified by a 20%-cold-working and Ti-adding from room temper- ature to 802℃. The created swelling is microscopically examined by the positron annihilation lifetime technique. A radiation swelling peak is observed at 580℃ and the corresponding void has an average diameter of 0.7 um which is hardly probed by macroscopic methods.展开更多
This paper resports the response of inoperable primary liver cancer to whole liver irradiation(WLI)by movingstrip technique(MST)during the period from 1980- 1988.The results showed that WLI by MST gave good response i...This paper resports the response of inoperable primary liver cancer to whole liver irradiation(WLI)by movingstrip technique(MST)during the period from 1980- 1988.The results showed that WLI by MST gave good response in this malignancy.The 5-year survival after treatment was 30.83% and median survival 25.8 months.The analysis of prognostic factors indicated that the higher the midplane tissue dose(mTD),the longer the survival(P<0.001),and that the survival of those patients tumor diameter was>8 to<13 cm and/or tumor volume>50% to <75% of liver volume was longer than that of there with tumor diameter of≥13 cm and/or tumor volume≥75% of the liver volume(P<0. 001 ).Traditional Chinese medicine is an indispensable therapy during the period of WLI by MST.Both clinical and experimental studies suggest that WLI by MST can enhance the therapeutic effect.展开更多
Effect of low-energy ion irradiation on plasma membrane permeability has been investigated by using electron spin resonance(ESR)spectroscopy of spin probe technique.The investigated system is plumule cells of wheat(Tr...Effect of low-energy ion irradiation on plasma membrane permeability has been investigated by using electron spin resonance(ESR)spectroscopy of spin probe technique.The investigated system is plumule cells of wheat(Triticum aestivum L.)seeds implanted by 30 keV N^(+) ions.ESR spectra indicated that plasmalemma permeability is sensitive to low-energy ion irradiation.Ion irradiations with increasing Huences up to semi-lethal dose lead to gradual increase in plasmalemma permeability of the plumule cells.The possible factors relevant to the changes in membrane permeability are discussed in relation to the changes in the physical state and chemical nature of membranes.展开更多
Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was...Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was used to study radiation effects on pyrochlore-rich synroc which contained simulated actinides. The amorphization and amorphous doses were determined by X-ray diffractometer (XRD) and transmission electron microscopy /select area electron diffraction (TEM/SAED). The vacancy defects induced by heavy-ion irradiation were characterized by using positron annihilation technique (PAT). The experimental results show that the amorphous dose is 0.5 dpa, the defects produced by heavy-ion irradiation are mainly voids, and irradiation could continue to intensify the vacancy defects even after the amorphous dose was reached.展开更多
Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 2...Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 220 cm ￣-1mode is attribute to As_1 which is associated, at least in part, with EL2 and EL12 defects.For Sedoped samples, the Raman peaks at 205 and 258 cm￣-1 may be due to vibrational modes in small clus-ters of arsenic, and the 77 and 185 ￣-1modes are probably associated with disorder-activated first order Ra-man scattering.Irradiated results show that the small clusters of arsenic and disorder state are increased with in-creasing irradiation fluences. Other Raman peaks will also be discussed in this paper.展开更多
文摘The work of the irradiation technique group of the material center is aimed at following two aspects:1. Technique support In 2015, we have had about 500 h beam time for 42 the single event effect (SEE) tests, which cooperating with various institutes, universities, and companies. The ground tests are the basic safeguard for the spacecraft and satellite. In order to raise the irradiation efficiency of the Terminal 5, an improvement of the sample transfer system has been accomplished. To study the dependency of SEE on the ion flux, a flip-flop composed of four kinds of structure test and analysis have been done. And some SEE simulation methods have been established.
基金Supported by the National Science Foundation of China(No.11305152)the Science and Technology Development Foundation of CAEP(Nos.2014B0103006 and 2012A0103002)
文摘A biaxial rotational technique is proposed to improve the neutron irradiation uniformity for a large sample,and the theoretical method is established to predict and design the main parameters. The technique used a device to rotate the target sample around two perpendicular axes simultaneously. Numerical calculations found that the lowest common multiple of the two angular speeds should be large enough to improve the uniformity,and the minimal experimental time should be no less than 600 s. For a three-dimensional sample with a size of 20 cm × 12 cm × 14 cm, the maximal non-uniform neutron irradiation factor of the sample is mainly determined by the distance between the center of the sample and of the point neutron source. It was computed to be less than 10% when the distance was no less than 34 cm. Experiments were carried out on the CFBR-II reactor and the experimental results were in good accordance with the theoretical analysis. As a result, the theoretical conclusions given above are reasonable and of reference value for the design of future irradiation experiments.
基金The project supported by the National Natural Science Foundation of China
文摘70 MeV-carbon-ion irradiation is used to simulate the radiation swelling induced by neutron irradiation of 3.2 × 1022 n·cm-2 in domestically-made 316 austenitic stainless steels modified by a 20%-cold-working and Ti-adding from room temper- ature to 802℃. The created swelling is microscopically examined by the positron annihilation lifetime technique. A radiation swelling peak is observed at 580℃ and the corresponding void has an average diameter of 0.7 um which is hardly probed by macroscopic methods.
文摘This paper resports the response of inoperable primary liver cancer to whole liver irradiation(WLI)by movingstrip technique(MST)during the period from 1980- 1988.The results showed that WLI by MST gave good response in this malignancy.The 5-year survival after treatment was 30.83% and median survival 25.8 months.The analysis of prognostic factors indicated that the higher the midplane tissue dose(mTD),the longer the survival(P<0.001),and that the survival of those patients tumor diameter was>8 to<13 cm and/or tumor volume>50% to <75% of liver volume was longer than that of there with tumor diameter of≥13 cm and/or tumor volume≥75% of the liver volume(P<0. 001 ).Traditional Chinese medicine is an indispensable therapy during the period of WLI by MST.Both clinical and experimental studies suggest that WLI by MST can enhance the therapeutic effect.
基金Supported in part by the National Natural Science Foundation of China under Grant No.19890302.
文摘Effect of low-energy ion irradiation on plasma membrane permeability has been investigated by using electron spin resonance(ESR)spectroscopy of spin probe technique.The investigated system is plumule cells of wheat(Triticum aestivum L.)seeds implanted by 30 keV N^(+) ions.ESR spectra indicated that plasmalemma permeability is sensitive to low-energy ion irradiation.Ion irradiations with increasing Huences up to semi-lethal dose lead to gradual increase in plasmalemma permeability of the plumule cells.The possible factors relevant to the changes in membrane permeability are discussed in relation to the changes in the physical state and chemical nature of membranes.
基金Supported by International Atomic Energy Agency under Contract No.10637
文摘Heavy-ion irradiation is commonly used to study radiation damage of high level radioactive waste (HLW) forms, but S ion was never used before. In this investigation, 100 MeV 32S ions produced by tandem accelerator was used to study radiation effects on pyrochlore-rich synroc which contained simulated actinides. The amorphization and amorphous doses were determined by X-ray diffractometer (XRD) and transmission electron microscopy /select area electron diffraction (TEM/SAED). The vacancy defects induced by heavy-ion irradiation were characterized by using positron annihilation technique (PAT). The experimental results show that the amorphous dose is 0.5 dpa, the defects produced by heavy-ion irradiation are mainly voids, and irradiation could continue to intensify the vacancy defects even after the amorphous dose was reached.
文摘Raman scattering measurements on Se-doped GaAs epitaxial layers and semi-insulating (SI) GaAs irradi-ated by 10 Mev electrons have been investigated. Several defect-related features were observed. We suggestthat the 220 cm ￣-1mode is attribute to As_1 which is associated, at least in part, with EL2 and EL12 defects.For Sedoped samples, the Raman peaks at 205 and 258 cm￣-1 may be due to vibrational modes in small clus-ters of arsenic, and the 77 and 185 ￣-1modes are probably associated with disorder-activated first order Ra-man scattering.Irradiated results show that the small clusters of arsenic and disorder state are increased with in-creasing irradiation fluences. Other Raman peaks will also be discussed in this paper.
