Review on synergistic damage effect of irradiation and corrosion on reactor structural alloys

The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research focus.This paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt reactors.The competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this paper.Conceptual approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.

Observation of therapeutic effect of lamp irradiation combined with purple gromwell oil gauze on alleviating intestinal colic in patients

BACKGROUND Intestinal colic is a common complication in patients who have undergone radical surgery for colorectal cancer.Traditional Chinese medicine has advantages,including safety and stability,for the treatment of intestinal colic.Lamp irra-diation for abdominal ironing has been applied in the treatment of many gas-trointestinal diseases.Purple gromwell oil has the effects of clearing heat,cooling blood,reducing swelling,and relieving pain.RESULTS The general effective rate in the observation group was 95.00%,which was significantly higher than that in the control group(86.67%,P<0.05).Before treatment,there was no significant difference in the duration of symptoms between the groups(P>0.05).After 1,2,3,and 4 d of treatment,the duration of symptoms in both groups were decreased,and the duration in the observation group was significantly lower than that in the control group(96.54±9.57 vs 110.45±11.23,87.26±12.07 vs 104.44±11.68,80.45±16.21 vs 99.44±14.95,73.18±15.58 vs 92.17±14.20;P<0.05).After 1,3,5,and 7 d of treatment,the NRS scores in both groups were decreased,and the NRS scores in the observation group were significantly lower than those in the control group(3.56±0.41 vs 4.04±0.58,3.07±0.67 vs 3.74±1.02,2.52±0.76 vs 3.43±0.85,2.03±0.58 vs 3.03±0.82;P<0.05).There was no significant difference in the rate of adverse reaction occurrence between the groups(P>0.05).CONCLUSION The use of lamp irradiation combined with purple gromwell oil gauze in patients with intestinal colic after radical surgery for colorectal cancer can reduce symptom duration,alleviate intestinal colic,and improve treatment efficacy,and this approach is safe.It is worth promoting the use of this treatment in clinical practice.

Neutron irradiation influence on high-power thyristor device under fusion environment

Because of their economy and applicability,high-power thyristor devices are widely used in the power supply systems for large fusion devices.When high-dose neutrons produced by deuterium–tritium(D–T)fusion reactions are irradiated on a thyristor device for a long time,the electrical characteristics of the device change,which may eventually cause irreversible damage.In this study,with the thyristor switch of the commutation circuit in the quench protection system(QPS)of a fusion device as the study object,the relationship between the internal physical structure and external electrical parameters of the irradiated thyristor is established.Subsequently,a series of targeted thyristor physical simulations and neutron irradiation experiments are conducted to verify the accuracy of the theoretical analysis.In addition,the effect of irradiated thyristor electrical characteristic changes on the entire QPS is studied by accurate simulation,providing valuable guidelines for the maintenance and renovation of the QPS.

Effects of Gamma-Ray Irradiation on Dielectric Surface Breakdown of Polybutylene Naphthalate and Polybutylene Terephthalate Under Reduced Pressure

With the increasing application of electric and electronic devices in space and nuclear power stations, the polymeric insulation materials are inevitably exposed to various kinds of environments. Accordingly, it becomes necessary to investigate the effects of the radiation and air pressure on insulation materials. This paper describes the effects of gamma-ray irradiation and reduced pressure on dielectric breakdown of polybutylene naphthalate (PBN) and polybutylene terephthalate (PBT) by applying a DC pulse voltage. Both PBN and PBT were irradiated in air up to 100 kGy and then up to 1 000 kGy with a dose rate of 10 kGy/h by using a60Co gamma-source. The effects of total dose and reduced pressure on the time to dielectric breakdown and discharge quantity were discussed. Obtained results show that, while increasing the total dose, the discharge quantity decreased with PBN, but increased with PBT. With decreasing the air pressure, the discharge quantity increased with PBN, but decreased with PBT. With increasing the total dose, the time to dielectric breakdown increased with PBN, but decreased with PBT. With decreasing the air pressure, the time to dielectric breakdown increased with both PBN and PBT. The experimental results suggest that the chemical structure of polybutylene polymers plays a main role in the result of radiation reaction, which is related to cross-linking and degradation reaction.

Effects of gamma-ray irradiation on electronic and non-electronic equipment of Large Helical Device

In a deuterium operation on the Large Helical Device, the measurement and control equipment placed in the toms hall must survive under an environment of radiation, To study the effects of gamma-ray irradiation on the equipment, an irradiation experiment is performed at the Cobalt-60 irradiation facility of Nagoya University. Transient and permanent effects on a personal computer, media converters, programmable logic controllers, isolation amplifiers, a web camera, optical flow meters, and water sealing gaskets are experimentally surveyed. Transient noise appears on the web camera. Offset of the signal increases with an increase of the integrated dose on the programmable logic controller. The DeviceNet module on the programmable logic controller is broken at the integrated dose of 72 Gy, which is the expected range of the integrated dose of the toms hall. The other equipment can survive under the gamma-ray field in the toms hall.

Study on Mutagenic Effect of Cobalt-60 Irradiation on Potato

[Objective] This study aimed to investigate the mutagenic effect of cobalt- 60 irradiation on potato. [Method] Potato tubers of Favorita and Zhongshu No.3 were irradiated with 5, 10, 20, 30, 50 and 70 Gy of cobalt-60 γ-ray respectively, to explore the mutagenic effect of different doses of γ-ray heavy ion irradiation on potato. [Result] The results showed that the emergence rate, seedling rate, plant growth, yield and commodity of potato varied after irradiated with different doses of cobalt-60 γ-ray; 10Gy of cobalt-60 irradiation played a positive effect on the growth and development of potato, while high doses played a negative effect on the growth and development of potato. After cobalt-60 irradiation, the botanical traits of M1 gen- eration varied greatly, resulting in a number of beneficial mutation traits; some traits of M2 and M3 generations became stably inherited. [Conclusion] Cobalt-60 irradiation breeding is conducive to the variety improvement and germplasm innovation as an effective means of genetic improvement for potato.

Synergistic effect of microwave irradiation and CaF2 on vanadium leaching

The effect and mechanism of microwave irradiation on vanadium leaching were studied via a comparison between microwave heating and conventional heating. The results show a synergistic effect of microwave irradiation and calcium fluoride （CaF2） on the vana- dium leaching efficiency. It is confirmed that the vanadium leaching process can be improved by microwave irradiation when CaF2 is present. The leaching rate of vanadium under microwave irradiation is increased by 8%-15% when 5wt% CaF2 is added; by contrast, in the absence of CaF2, the leaching rate is almost unaffected compared to that by conventional heating. Morphological analysis reveals that the particles are gradually eroded by acid under microwave irradiation, whereas some of the fine particles in samples subjected to conventional heating are tightly covered by a flocculent silicate product. Moreover, a large amount of A1 and V and a small amount of Si are dissolved from samples under microwave heating, as revealed by the elemental analysis of leachates. Fourier transform infrared spectroscopic analysis also indicates a higher mass transfer coefficient in the diffusion layer of the raw material by microwave irradiation. When CaF2 is present, the reaction energy barrier is lowered and the leaching process is controlled by the tightly covered product layer, resulting in a prominent effect of mi- crowave irradiation.

Irradiation effect on strain sensitivity coefficient of strain sensing fiber Bragg gratings

The effect of irradiation on the strain sensitivity coefficient of strain sensing fiber Bragg gratings （FBGs） has been investigated through experiments. FBGs were fabricated in single mode fibers with 3 tool% Ge-concentration in the core and with a H2-1oading treatment. In experiments, the FBGs were subjected to y-radiation exposures using a Co6~ source at a dose-rate of 25 Gy/min up to a total dose of 10.5 kGy. The GeO defect in fiber absorbs photons to form a GeE＇ defect; the interaction with H2 is a probable reason for the y-radiation sensitivity of gratings written in hydrogen loaded fibres, The effect mechanism of radiation on the strain sensitivity coefficient is similar to that of radiation on the temperature sensitivity coefficient. Radiation affects the effective index neff, which results in the change of the thermo-optic coefficient and the strain-optic coefficient. Irradiation can change the strain sensitivity coefficient of FBGs by 1.48%-2.71%, as well as changing the Bragg wavelength shift （BWS） by 22 pm-25 pm under a total dose of 10.5 kGy. Our research demonstrates that the effect of irradiation on the strain sensitivity coefficient of FBG is small and that strain sensing FBGs can work well in the radiation environment.

Radiation-hardened property of single-walled carbon nanotube film-based field-effect transistors under low-energy proton irradiation

Strong C-C bonds,nanoscale cross-section and low atomic number make single-walled carbon nanotubes(SWCNTs)a potential candidate material for integrated circuits(ICs)applied in outer space.However,very little work combines the simulation calculations with the electrical measurements of SWCNT field-effect transistors(FETs),which limits further understanding on the mechanisms of radiation effects.Here,SWCNT film-based FETs were fabricated to explore the total ionizing dose(TID)and displacement damage effect on the electrical performance under low-energy proton irradiation with different fluences up to 1×1015 p/cm2.Large negative shift of the threshold voltage and obvious decrease of the on-state current verified the TID effect caused in the oxide layer.The stability of the subthreshold swing and the off-state current reveals that the displacement damage caused in the CNT layer is not serious,which proves that the CNT film is radiation-hardened.Specially,according to the simulation,we found the displacement damage caused by protons is different in the source/drain contact area and channel area,leading to varying degrees of change for the contact resistance and sheet resistance.Having analyzed the simulation results and electrical measurements,we explained the low-energy proton irradiation mechanism of the CNT FETs,which is essential for the construction of radiation-hardened CNT film-based ICs for aircrafts.

Protective Effects of Shikonin on Brain Injury Induced by Carbon Ion Beam Irradiation in Mice

Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group （P〈0.01）, while obviously reduced the MDA and PCO contents and the RO$ levels derived from of the brain mitochondria.

Dynamic characteristics of charging effects on the dielectric constant due to E-beam irradiation:a numerical simulation

A series of synthetic variations of material intrinsic properties always come with charging phenomena due to electron beam irradiation.The effects of charging on the dielectric constant will influence the charging dynamic in return.In this paper,we propose a numerical simulation for investigating the dynamic characteristics of charging effects on the dielectric constant due to electron beam irradiation.The scattering process between electrons and atoms is calculated considering elastic and inelastic collisions via the Rutherford model and the fast secondary electron model,respectively.Internal charge drift due to E-field,density gradient caused diffusion,charges trap by material defect,free electron and hole neutralization,and variation in the internal dielectric constant are considered when simulating the transport process.The dynamics of electron and hole distributions and charging states are demonstrated during E-beam irradiation.As a function of material nonlinear susceptibility and primary energy,the dynamics of charging states and dielectric constants are then presented in the charging process.It is found that the variation in the internal dielectric constant is more with respect to the depth and irradiation time.Material with a larger nonlinear susceptibility corresponds a faster charging enhancement.In addition,the effective dielectric constant and the surface potential have a linear relationship in the charging balance.Nevertheless,with shrinking charging affect range,the situation with a higher energy primary electron comes with less dielectric constant variation.The proposed numerical simulation mode of the charging process and the results presented in this study offer a comprehensive insight into the complicated charging phenomena in electron irradiation related fields.

Effect of Irradiation on Crystallinity and Mechanical Properties of Ultrahigh-Molecular-Weight Polyethylene

Ultrahigh-molecular-weight polyethylene(UtlMWPE) has been irradiated (0-40 Mrad) with a Co^(60) source at room temperature under vacuum. Their crystallinity has been investigated by DSC and SAXS A significant increase of heat of fusion can be seen at low irradiation doses, which is attributed to crystallization caused by chain scission during the process of irradiation. It is also observed that thickness of lamellae changes with irradiation dose. Young's modulus has been improved significantly after irradiation at low doses.

Study on the Antitumor Effects of Low-energy Laser Irradiation Combined with Cyclophosphamide

Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascites sarcoma.The three groups of tumor bearing mice were irradiated upon the inner corners with the dosages of 11 00,14 67 and 22 00 J·cm -2 LELI respectively,and injected with CYT intraperitoneally to observe the changes of the survival time,the ascites growth speed,and the kinetic changes of immune functions.The survival times of the three groups of CYT/LELI combination were obviously longer than those of the tumor and CYT control groups.Correspondingly,the amounts of ascites,tumor cells densities and total tumor cells in CYT/LELI groups decreased significantly,while the death ratio of the tumor cells increased.Comparatively,the group of 22 00 J·cm -2 LELI combined with CYT showed the most ideal antitumor effects,and the life prolongation ratio was up to 53 20%.

Effect of UV-B irradiation on interspecific competition between Ulva pertusa and Grateloupia filicina

We report the effect of UVoB irradiation （9.6 kJ m-2 day^-） on interspecific competition between two species of macroalgae, Ulva pertusa （U） and Grateloupiafilicina （G）, in co-culture. Growth of U. pertusa and G. filicina was inhibited by UV-B irradiation in mono-culture and specific growth rate （μ） declined as a result. Interspecific competition between U. pertusa and G filicina was closely related to the initial weights when co-cultured. When initial ratios of U. pertusa （U） to G filicina （G） were U：G=I.2：I and 1：1, U. pertusa was the dominant algae. When the initial U：G ratio was 1：1.2, G. filicina was competitively dominant in the earlier stage, but U. pertusa grew faster, superseding G. filicina in the later stage. At initial ration U：G = 1：1.4, G. filicina was predominant. Under UV-B irradiation, the competitive ability of G filicina was weakened and the interspecific competitive balance favored U. pertusa, which suggests that G. filicina was more sensitive to UV-B irradiation. We also probed the potential allelopathic effects between the two species, which led to mutual growth inhibition.

Analysis of Combined Therapy and Treatment Effect of Localized Ultraviolet Irradiation and Shengji Yuhong Cream on Diabetic Foot

Objective:To investigate the treatment effect of combined application of localized ultraviolet irradiation and Shengji Yuhong Cream on diabetic foot patients.Methods:Diabetic foot patients in the control group were treated with localized ultraviolet irradiation on the basis of conventional treatment.The study group was added with Shengji Yuhong Cream on top of the localized ultraviolet irradiation on the basis of conventional treatment.Results:The results of ankle brachial index and dorsal foot skin temperature of that two groups before treatment were compared,P>0.05.After treatment,the ankle brachial index and dorsal foot skin temperature of the study group were better than those of the control group.The comparison between the groups and within the group was P<0.05.The total effective rate of the study group(95.65%)was higher than that of the control group(71.11%),P<0.05.Conclusion:The application of localized ultraviolet irradiation and Shengji Yuhong Cream in the treatment of diabetic foot is effective.

Solvent effects on gold nanoparticle formation from photochemical reduction of Au(Ⅲ)by UV irradiation

Colloidal gold nanoparticles(AuNPs) have attracted more and more attention in areas of materials science, biotechnology and organic chemistry due to their unique functions as molecular markers and their applications in diagnostic imaging and catalysis. The AuNP synthesis approaches have been well developed; however, the solvent effects have not been systematically studied yet.Here we analyzed and compared solvent effects on AuNP formation using UV irradiation of Au(Ⅲ) without adding any other ligands. By monitoring the surface plasmonresonance absorption of Au(Ⅲ)-containing solutions,results showed that both ketone and alcohol solvents can induce Au(Ⅲ) to form gold nanospheres; on the other hand, solvents like ACN and THF can induce Au(Ⅲ) to form nanostructures with longer dimensions. The possible mechanism was discussed, which could facilitate efficient photochemical synthesis of AuNPs and might apply to other metal NP synthesis.

Study of leakage current degradation based on stacking faults expansion in irradiated SiC junction barrier Schottky diodes

A comprehensive investigation was conducted to explore the degradation mechanism of leakage current in SiC junction barrier Schottky(JBS)diodes under heavy ion irradiation.We propose and verify that the generation of stacking faults(SFs)induced by the recombination of massive electron-hole pairs during irradiation is the cause of reverse leakage current degradation based on experiments results.The irradiation experiment was carried out based on Ta ions with high linear energy transfer(LET)of 90.5 MeV/(mg/cm^(2)).It is observed that the leakage current of the diode undergoes the permanent increase during irradiation when biased at 20%of the rated reverse voltage.Micro-PL spectroscopy and PL micro-imaging were utilized to detect the presence of SFs in the irradiated SiC JBS diodes.We combined the degraded performance of irradiated samples with SFs introduced by heavy ion irradiation.Finally,three-dimensional(3D)TCAD simulation was employed to evaluate the excessive electron-hole pairs(EHPs)concentration excited by heavy ion irradiation.It was observed that the excessive hole concentration under irradiation exceeded significantly the threshold hole concentration necessary for the expansion of SFs in the substrate.The proposed mechanism suggests that the process and material characteristics of the silicon carbide should be considered in order to reinforcing against the single event effect of SiC power devices.

Synergistic effects of neutron and gamma ray irradiation of a commercial CHMOS microcontroller

This paper presents the experimental results of a combined irradiation environment of neutron and gamma rays on 80C196KC20, which is a 16-bit high performance member of the MCS96 microcontroller family. The electrical and functional tests were made in three irradiation environments： neutron, gamma rays, combined irradiation of neutron and gamma rays. The experimental results show that the neutron irradiation can affect the total ionizing dose behaviour. Compared with the single radiation environment, the microcontroller exhibits considerably more severe degradation in neutron and gamma ray synergistic irradiation. This phenomenon may cause a significant hardness assurance problem.

Irradiation effects of graphene and thin layer graphite induced by swift heavy ions

Graphene and thin graphite films deposited on SiO2/Si are irradiated by swift heavy ions(209Bi, 9.5 Me V/u) with the fluences in a range of 1011ions/cm2–1012ions/cm2 at room temperature. Both pristine and irradiated samples are investigated by Raman spectroscopy. For pristine graphite films, the 'blue shift' of 2D bond and the 'red shift' of G bond with the decrease of thickness are found in the Raman spectra. For both irradiated graphene and thin graphite films, the disorder-induced D peak and D' peak are detected at the fluence above a threshold Φth. The thinner the film, the lower the Φthis. In this work, the graphite films thicker than 60 nm reveal defect free via the absence of a D bond signal under the swift heavy ion irradiation till the fluence of 2.6 × 1012ions/cm2. For graphite films thinner than 6 nm, the area ratios between D peak and G peak increase sharply with reducing film thickness. It concludes that it is much easier to induce defects in thinner films than in thicker ones by swift heavy ions. The intensities of the D peak and D' peak increase with increasing ion fluence, which predicts the continuous impacting of swift heavy ions can lead to the increasing of defects in samples. Different defect types are detected in graphite films of different thickness values. The main defect types are discussed via the various intensity ratios between the D peak and D' peak(HD/HD).

Single event effect in a ferroelectric-gate field-effect transistor under heavy-ion irradiation

The single event effect in ferroelectric-gate field-effect transistor （FeFET） under heavy ion irradiation is investigated in this paper. The simulation results show that the transient responses are much lower in a FeFET than in a conventional metal-oxide-semiconductor field-effect transistor （MOSFET） when the ion strikes the channel. The main reason is that the polarization-induced charges （the polarization direction here is away from the silicon surface） bring a negative surface po- tential which will affect the distribution of carders and charge collection in different electrodes significantly. The simulation results are expected to explain that the FeFET has a relatively good immunity to single event effect.