This study investigates the coupling response of cables inside a metal cavity under X-ray irradiation using the finite-difference time-domain method,particle simulation method,and transmission-line equation to solve t...This study investigates the coupling response of cables inside a metal cavity under X-ray irradiation using the finite-difference time-domain method,particle simulation method,and transmission-line equation to solve the electromagnetic field inside the cavity and load voltage at the cable terminal under X-ray excitation.The results show that under a strong ionizing radiation environment of 1 J/cm^(2),a strong electromagnetic environment is generated inside the cavity.The cable shielding layer terminal couples a voltage of 15.32 V,whereas the core wire terminal couples a voltage of 0.31 V.Under strong X-ray irradiation,the metal cavity not only fails to provide electromagnetic shielding,but also introduces new electromagnetic interference.This study also provides a method for reducing the number of emitted electrons by adding low-Z materials,which can effectively reduce the coupled electric field and voltage.展开更多
This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circ...This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circularly polarized laser pulses of varying intensities. We examine the effects of the transverse ponderomotive force, specifically how the deviation angle and speed of electron motion are affected by the initial off-axis position of the electron and the peak amplitude of the laser pulse. When the laser pulse intensity is low, an increase in the electron's initial off-axis distance results in reduced spatial radiation power, improved collimation, super-continuum phenomena generation, red-shifting of the spectrum's harmonic peak, and significant symmetry in the radiation radial direction. However, in contradiction to conventional understandings,when the laser pulse intensity is relatively high, the properties of the relativistic nonlinear Thomson inverse scattering of the electron deviate from the central axis, changing direction in opposition to the aforementioned effects. After reaching a peak, these properties then shift again, aligning with the previous direction. The complex interplay of these effects suggests a greater nuance and intricacy in the relationship between laser pulse intensity, electron position, and scattering properties than previously thought.展开更多
The Trichel pulse stage is an unstable stage of negative corona discharge that can also involve electromagnetic(EM) radiation signals. In this paper, the discharge mechanism and radiation characteristics of the Triche...The Trichel pulse stage is an unstable stage of negative corona discharge that can also involve electromagnetic(EM) radiation signals. In this paper, the discharge mechanism and radiation characteristics of the Trichel pulse are studied in the needle-plate electrode configuration. The Trichel pulse current and its EM radiation signals are measured at different applied voltages.The results show that Trichel pulse discharge changes from the random pulse stage to the continuous pulse stage as the applied voltage increases. During these different stages, the normalized shape of the Trichel pulses remains unchanged, while the frequency of the EM radiation generated by the discharge remains unchanged. The discharge mechanism and EM radiation characteristics of the Trichel pulse are theoretically analyzed in the different stages.Both the positive ion sheath and the negative ion cloud play key roles in the formation of the Trichel pulse. The EM radiation signal is generated by the rapidly changing Trichel pulse current, and the Trichel pulse current waveform determines the characteristics of the EM radiation signal.展开更多
We present the first simulation results of a multi-shell target ignition driven by Z-pinch dynamic hohlraum radiation pulse.The radiation pulse is produced with a special Z-pinch dynamic hohlraum configuration,where t...We present the first simulation results of a multi-shell target ignition driven by Z-pinch dynamic hohlraum radiation pulse.The radiation pulse is produced with a special Z-pinch dynamic hohlraum configuration,where the hohlraum is composed of a single metal liner,a low-Z plastic foam,and a high-Z metallic foam.The implosion dynamics of a hohlraum and a multi-shell target are investigated separately by the one-dimensional code MULTI-IFE.When the peak drive current is 50 MA,simulations suggest that an x-ray pulse with nearly constant radiation temperature(-310 eV)and a duration about 9 ns can be obtained.A small multi-shell target with a radius of 1.35 mm driven by this radiation pulse is able to achieve volumetric ignition with an energy gain(G)about 6.19,where G is the ratio of the yield to the absorbed radiation.Through this research,we better understand the effects of non-uniformities and hydrodynamics instabilities in Z-pinch dynamic hohlraum.展开更多
The analytic representation of the transient radiation for an aperture excited by a rectangle pulse is obtained. It shows that the field duration and amplitude depend on the observation distance, the elevation angle, ...The analytic representation of the transient radiation for an aperture excited by a rectangle pulse is obtained. It shows that the field duration and amplitude depend on the observation distance, the elevation angle, the pulse width of the rectangle pulse and the aperture size.展开更多
Pulse X-ray diagnostics is capable of reducing the radiation exposure considerably. As for pulse X-ray diagnostic machines, which form pulses with the duration of 0.1 μs, using them one can get outstanding results in...Pulse X-ray diagnostics is capable of reducing the radiation exposure considerably. As for pulse X-ray diagnostic machines, which form pulses with the duration of 0.1 μs, using them one can get outstanding results in this area. This fact can be explained by the long period of luminophor persistence in intensifying X-ray luminescent screens. In this paper we present experimental data, comparing radiation doses, measured at pulse X-ray apparatus and apparatus of constant radiation.展开更多
Use of Electronic gadgets such as mobile phones, computers/laptops constitutes an integral part of human day-to-day activity in offices and businesses. Therefore, their use cannot be stopped. These electronic gadgets ...Use of Electronic gadgets such as mobile phones, computers/laptops constitutes an integral part of human day-to-day activity in offices and businesses. Therefore, their use cannot be stopped. These electronic gadgets emit electromagnetic radiations, which are believed to be hazardous to human health. World Health Organization/International Agency for Research on Cancer has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group B). The Enviro Chip developed by Synergy Environics, India, is a radiation harmonizing chip which when fixed on electronic gadgets at specific locations claims to reduce stress level by reducing the pulse rate of users which may also result in improvement of other health parameters. In this study, we have tested the ability of the Enviro Chip to reduce pulse rate of people who may have developed high pulse rate due to prolonged use of electronic gadgets. This was the double blind crossover study conducted in 205 healthy volunteers having an average pulse rate of above 82 per Minute at Max Healthcare India. The primary objective of the study was to evaluate and compare the change in pulse rate over 14 measurements with the use of both the Enviro Chip and a Dummy chip from average pulse rate at baseline without the Placebo effect. The secondary objective was to evaluate the change in pulse rate gender-wise. Data analysis was done using Wilcoxon Sign Rank test. The study demonstrated statistical significant reduction in pulse rate over 14 measurements with the use of Enviro Chip in both male and female healthy volunteers展开更多
In this paper,we studied the effects of physical factors,such as,acoustic pulses of laser-induced hydrodynamics(ALIH)and extremely-high frequencies(EHF)radiation,on the formation of heterotopic bone marrow organs.A su...In this paper,we studied the effects of physical factors,such as,acoustic pulses of laser-induced hydrodynamics(ALIH)and extremely-high frequencies(EHF)radiation,on the formation of heterotopic bone marrow organs.A suspension of precipitated bone marrow cells from CBA mice were exposed to ALIH pulses and EHF radiation separately and in their com bination tissue engineering constructs,presenting gelatin sponges 2 by 2 by 2 mm in size containing 10^(7)nucleated bone marrow cells,were exposed to physical factors and were implanted under the renal capsules of syngeneic mice.The newly formed hematopoietic organs were examined in three and five months later after treatment.The five months old transplants were bigger in size than the three months old transplants.The number of hematopoietic cells in the rest of the groups increased during this period by a factor from 3 to 10,the increase being as high as 20-fold in the:ALH+EHF group.Maximal concentration of multipotent stromal cells(MSCs)was in the EHF+ALIH,and minimal concentration was in the ALIH+EHF.The accumulation rate of bone capsule weight was highest for the transplants of EHF+ALIH and ALIH-sponge groups during the first three months.These data showed that the combined impact of the EHF+ALIH on MSCs is the most effective for the formation of bone marrow transplantation.展开更多
In this study,the anti-noise performance of a pulse-coupled neural network(PCNN)was investigated in the neutron and gamma-ray(n-γ)discrimination field.The experiments were conducted in two groups.In the first group,r...In this study,the anti-noise performance of a pulse-coupled neural network(PCNN)was investigated in the neutron and gamma-ray(n-γ)discrimination field.The experiments were conducted in two groups.In the first group,radiation pulse signals were pre-processed using a Fourier filter to reduce the original noise in the signals,whereas in the second group,the original noise was left untouched to simulate an extremely high-noise scenario.For each part,artificial Gaussian noise with different intensity levels was added to the signals prior to the discrimination process.In the aforementioned conditions,the performance of the PCNN was evaluated and compared with five other commonly used methods of n-γdiscrimination:(1)zero crossing,(2)charge comparison,(3)vector projection,(4)falling edge percentage slope,and(5)frequency gradient analysis.The experimental results showed that the PCNN method significantly outperforms other methods with outstanding FoM-value at all noise levels.Furthermore,the fluctuations in FoM-value of PCNN were significantly better than those obtained via other methods at most noise levels and only slightly worse than those obtained via the charge comparison and zerocrossing methods under extreme noise conditions.Additionally,the changing patterns and fluctuations of the FoMvalue were evaluated under different noise conditions.Hence,based on the results,the parameter selection strategy of the PCNN was presented.In conclusion,the PCNN method is suitable for use in high-noise application scenarios for n-γdiscrimination because of its stability and remarkable discrimination performance.It does not rely on strict parameter settings and can realize satisfactory performance over a wide parameter range.展开更多
Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate (TMPTA) was incorporated in...Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate (TMPTA) was incorporated into poly(ethylene terephthalate) (PET)/random terpolymer elastomer (ST2000) blends by melt-blending. The existence of TMPTA would induce the crosslinking of PET and ST2000 molecular chains at high temperatures of blend- ing, resulting in the improvement in the impact strength but the loss in the tensile strength. When the PET/ST2000 blends were irradiated by gamma-ray radiation, the integrated me- chanical properties could be enhanced significantly at a high absorbed dose. The irradiated sample at a dose of 100 kGy even couldn't be broken under the impact test load, and at the same time, has nearly no loss of tensile strength. Based on the analysis of the impact- fractured surface morphologies of the blends, it can be concluded that gamma-ray radiation at high absorbed dose can further in situ enhance the interfacial adhesion by promoting the crosslinking reactions of TMPTA and polymer chains. As a result, the toughness and strength of PET/ST2000 blend could be dramatically improved. This work provides a facial and practical way to the fabrication of polymer blends with high toughness and strength.展开更多
Ultrawideband electromagnetic pulses with high amplitude and short duration are reported to affect several aspects of cell physiology. They are usually delivered to the living material through electrodes in small dedi...Ultrawideband electromagnetic pulses with high amplitude and short duration are reported to affect several aspects of cell physiology. They are usually delivered to the living material through electrodes in small dedicated chambers. Here we showed, using a totally different experimental setup, that radiated EM pulses illuminating the living material through a specialized antenna (without any direct contact) are able to trigger a rapid release of ATP in cultured murine cells that was concomitant with a drop of intracellular AEC. Despite this rapid and strong response, we found that cell viability and clonogenicity were only slightly affected by the EMF exposure.展开更多
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 ...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.展开更多
Thanks to more and more gamma-ray bursts with measured redshift and extended emission detected by the recent space telescopes,it is urgent and possible to check whether those previous energy correlations still satisfy...Thanks to more and more gamma-ray bursts with measured redshift and extended emission detected by the recent space telescopes,it is urgent and possible to check whether those previous energy correlations still satisfy the particular sample involving only the bursts accompanied by tail radiations.Using 20 long and 22 short bursts with extended emission,we find that the popular γ-ray energy correlations of the intrinsic peak energy versus the isotropic energy(Amati relation) and the intrinsic peak energy versus the peak luminosity(Yonetoku relation) do exist in both short and long bursts.However,it is much better if these gamma-ray bursts with extended emissions are reclassified into two subgroups of E-Ⅰ and E-Ⅱ that make the above energy correlations more tight.As proposed by Zhang et al.,the energy correlations can be utilized to distinguish these kinds of gamma-ray bursts in the plane of bolometric fluence versus peak energy as well.Interestingly,the peculiar short GRB 170817 A belongs to the E-Ⅰ group in the fluence versus peak energy plane,but it is an outlier of both the Amati and Yonetoku relations even though the off-axis effect has been corrected.Furthermore,we compare the radiation features between the extended emissions and the prompt gamma-rays in order to search for their possible connections.Taking into account all these factors,we conclude that gamma-ray bursts with extended emission are still required to model with dichotomic groups,namely E-Ⅰ and E-Ⅱ classes,which hint that they might have different origins.展开更多
With the development of laser technologies,nuclear reactions can happen in high-temperature plasma environments induced by lasers and have attracted a lot of attention from different physical disciplines.However,studi...With the development of laser technologies,nuclear reactions can happen in high-temperature plasma environments induced by lasers and have attracted a lot of attention from different physical disciplines.However,studies on nuclear reactions in plasma are still limited by detecting technologies.This is mainly due to the fact that extremely high electromagnetic pulses(EMPs)can also be induced when high-intensity lasers hit targets to induce plasma,and then cause dysfunction of many types of traditional detectors.Therefore,new particle detecting technologies are highly needed.In this paper,we report a recently developed gated fiber detector which can be used in harsh EMP environments.In this prototype detector,scintillating photons are coupled by fiber and then transferred to a gated photomultiplier tube which is located far away from the EMP source and shielded well.With those measures,the EMPs can be avoided which may result that the device has the capability to identify a single event of nuclear reaction products generated in laser-induced plasma from noise EMP backgrounds.This new type of detector can be widely used as a time-of-flight(TOF)detector in high-intensity laser nuclear physics experiments for detecting neutrons,photons,and other charged particles.展开更多
Identifying the unknown geometric and material information of a multi-shield object by analyzing the radiation signature measurements is always an important problem in national and global security. In order to identif...Identifying the unknown geometric and material information of a multi-shield object by analyzing the radiation signature measurements is always an important problem in national and global security. In order to identify the unknown shielding layer thicknesses of a source/shield system with gamma-ray spectra, we have developed a derivative-free inverse radiation transport model based on a differential evolution algorithm with global and local neighbourhoods(IRT-DEGL). In the present paper, the IRT-DEGL model is further extended for estimating the unknown thicknesses with random initial guesses and material mass densities of multi-shielding layers as well as their combinations. Using the detected gamma-ray spectra,the illustration of inverse studies is implemented and the main influence factors for inverse results are also analyzed.展开更多
Radiation simulation utilizing plasma radiation sources (PRS) generates a large number of undesirable debris, which may damage the expensive diagnosing detectors. An ultra fast shutter (UFS) driven by pulsed high curr...Radiation simulation utilizing plasma radiation sources (PRS) generates a large number of undesirable debris, which may damage the expensive diagnosing detectors. An ultra fast shutter (UFS) driven by pulsed high current can erect a physical barrier to the slowly moving debris after allowing the passage of X-ray photons. The UFS consists of a pair of thin metal foils twisting the parallel axes in a Nylon cassette, compressed with an outer magnetic field, generated from a fast capacitor bank, discharging into a single turn loop. A typical capacitor bank is of 7.5μF charging voltages varying from 30 kV to 45 kV, with corresponding currents of approximately 90 kA to140 kA and discharging current periods of approximately 13.1μs. A shutter closing time as fast as 38 microseconds has been obtained with an aluminium foil thickness of 100 micrometers and a cross-sectional area of 15 mm by 20 mm. The design, construction and the expressions of the valve-closing time of the UFS are presented along with the measured results of valve-closing velocities.展开更多
A Cherenkowtype terahertz electromagnetic radiation is revealed, which results efficiently from the collective effects in the time-domain of ultrafast pulsed electron current produced by ultrafast intense laser plasma...A Cherenkowtype terahertz electromagnetic radiation is revealed, which results efficiently from the collective effects in the time-domain of ultrafast pulsed electron current produced by ultrafast intense laser plasma interaction. The emitted pulse waveform and spectrum, and the dependence of laser pulse parameters on the structure of the radiation field are investigated numerically. The condition of THz radiation generation in this regime and Cherenkov geometry of the radiation field are studied analytically.展开更多
An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the...An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and展开更多
A method is proposed to characterize the fast neutron scattering cross-section ( s f) quantitatively by the combina-tion of inelastic gamma rays and captured gamma rays, so as to realize the gas saturation evaluation ...A method is proposed to characterize the fast neutron scattering cross-section ( s f) quantitatively by the combina-tion of inelastic gamma rays and captured gamma rays, so as to realize the gas saturation evaluation of CO_(2)-injected heavy oilreservoirs based on the three-de tector pulsed neutron logging technology. Factors influencing of the evaluation effect of thismethod are analyzed and the effectiveness of this method is verified by a simulation example. By using the Monte Carlo simu-lation method and the physical model of bulk-volume rock, the relationship between s f and CO_(2) saturation is studied, and thesaturation interpretation model is established. The influences of formation temperature and pressure, heavy oil density, bore-hole fluid and reservoir methane content on the evaluation results of CO_(2) saturation are analyzed. The results show that thecharacterization of s f by the combination of secondary gamma information can eliminate the influence of formation lithology,borehole fluid and methane content are the main factors affecting the quantitative monitoring of CO_(2) saturation, and the ef-fects of formation temperature and pressure and heavy oil density are negligible. The simulation example verified the feasibilityof the method for evaluating the CO_(2) saturation of CO_(2)-injected heavy oil reservoirs.展开更多
Objective:To investigate the clinical assessment of thyroid carcinoma in acoustic pulse radiation imaging and the correlation analysis of osteopontin expression.Methods: A total of 71 lesions of 60 patients with thyro...Objective:To investigate the clinical assessment of thyroid carcinoma in acoustic pulse radiation imaging and the correlation analysis of osteopontin expression.Methods: A total of 71 lesions of 60 patients with thyroid carcinoma (TC) in Hainan were selected. All patients were graded by TI-RADS grading and confirmed by pathology after operation. The expression of OPN was detected by immunohistochemical S-P method. The expression of OPN mRNA was detected by fluorescence quantitative polymerase chain reaction. The correlation between OPN expression and acoustic pulse radiation imaging was analyzed.Results:(1) 60 patients (93.33%) with primary TC and 4 (6.67%) patients with secondary TC were found in 60 patients with TC. Thirty-seven patients (61.67% according to the pathological features, 32 cases (53.33%) had papillary TC, diffuse sclerosis 19 cases of diffuse sclerosis PTC (31.67%), follicular carcinoma in 9 cases (15.00%). (2) The expression of OPN mRNA in 37 cases of calcified TC was significantly higher than that in non-calcified TC, and the increase of OPN expression was in direct proportion to the distribution of gritty calcification.Conclusions: The distribution of calcified microsomes in TC was positively correlated with the expression of OPN, suggesting that enhanced OPN expression may be related to the formation of psammoma bodies, the increased hardness of nodules and the increased malignancy. Acoustic pulse radiation imaging technology for early diagnosis of TC and prognosis of TC was of great significance.展开更多
文摘This study investigates the coupling response of cables inside a metal cavity under X-ray irradiation using the finite-difference time-domain method,particle simulation method,and transmission-line equation to solve the electromagnetic field inside the cavity and load voltage at the cable terminal under X-ray excitation.The results show that under a strong ionizing radiation environment of 1 J/cm^(2),a strong electromagnetic environment is generated inside the cavity.The cable shielding layer terminal couples a voltage of 15.32 V,whereas the core wire terminal couples a voltage of 0.31 V.Under strong X-ray irradiation,the metal cavity not only fails to provide electromagnetic shielding,but also introduces new electromagnetic interference.This study also provides a method for reducing the number of emitted electrons by adding low-Z materials,which can effectively reduce the coupled electric field and voltage.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10947170/A05 and 11104291)the Natural Science Fund for Colleges and Universities in Jiangsu Province (Grant No.10KJB140006)+2 种基金the Natural Sciences Foundation of Shanghai (Grant No.11ZR1441300)the Natural Science Foundation of Nanjing University of Posts and Telecommunications (Grant No.NY221098)the Jiangsu Qing Lan Project for their sponsorship。
文摘This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circularly polarized laser pulses of varying intensities. We examine the effects of the transverse ponderomotive force, specifically how the deviation angle and speed of electron motion are affected by the initial off-axis position of the electron and the peak amplitude of the laser pulse. When the laser pulse intensity is low, an increase in the electron's initial off-axis distance results in reduced spatial radiation power, improved collimation, super-continuum phenomena generation, red-shifting of the spectrum's harmonic peak, and significant symmetry in the radiation radial direction. However, in contradiction to conventional understandings,when the laser pulse intensity is relatively high, the properties of the relativistic nonlinear Thomson inverse scattering of the electron deviate from the central axis, changing direction in opposition to the aforementioned effects. After reaching a peak, these properties then shift again, aligning with the previous direction. The complex interplay of these effects suggests a greater nuance and intricacy in the relationship between laser pulse intensity, electron position, and scattering properties than previously thought.
基金supported by National Natural Science Foundation of China(No.U1630130)
文摘The Trichel pulse stage is an unstable stage of negative corona discharge that can also involve electromagnetic(EM) radiation signals. In this paper, the discharge mechanism and radiation characteristics of the Trichel pulse are studied in the needle-plate electrode configuration. The Trichel pulse current and its EM radiation signals are measured at different applied voltages.The results show that Trichel pulse discharge changes from the random pulse stage to the continuous pulse stage as the applied voltage increases. During these different stages, the normalized shape of the Trichel pulses remains unchanged, while the frequency of the EM radiation generated by the discharge remains unchanged. The discharge mechanism and EM radiation characteristics of the Trichel pulse are theoretically analyzed in the different stages.Both the positive ion sheath and the negative ion cloud play key roles in the formation of the Trichel pulse. The EM radiation signal is generated by the rapidly changing Trichel pulse current, and the Trichel pulse current waveform determines the characteristics of the EM radiation signal.
基金Project supported by the Science Challenge Project (Grant No. TZ2018001)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos. XDA25051200 and XDA25050200)+4 种基金the National Natural Science Foundation of China (Grant Nos. 11705282 and 11775305)Hunan Graduate Scientific Research Innovation Project (Grant No. CX20190001)supported by the spanish “Ministerio de Ciencia Innovación y Universidades”project RTI2018-098801-B-100the Spanish “Ministerio de Economía y Competitividad” Project ENE2014-54960-Rthe EURO fusion Consortium project AWP15-ENR-01/CEA-02
文摘We present the first simulation results of a multi-shell target ignition driven by Z-pinch dynamic hohlraum radiation pulse.The radiation pulse is produced with a special Z-pinch dynamic hohlraum configuration,where the hohlraum is composed of a single metal liner,a low-Z plastic foam,and a high-Z metallic foam.The implosion dynamics of a hohlraum and a multi-shell target are investigated separately by the one-dimensional code MULTI-IFE.When the peak drive current is 50 MA,simulations suggest that an x-ray pulse with nearly constant radiation temperature(-310 eV)and a duration about 9 ns can be obtained.A small multi-shell target with a radius of 1.35 mm driven by this radiation pulse is able to achieve volumetric ignition with an energy gain(G)about 6.19,where G is the ratio of the yield to the absorbed radiation.Through this research,we better understand the effects of non-uniformities and hydrodynamics instabilities in Z-pinch dynamic hohlraum.
文摘The analytic representation of the transient radiation for an aperture excited by a rectangle pulse is obtained. It shows that the field duration and amplitude depend on the observation distance, the elevation angle, the pulse width of the rectangle pulse and the aperture size.
文摘Pulse X-ray diagnostics is capable of reducing the radiation exposure considerably. As for pulse X-ray diagnostic machines, which form pulses with the duration of 0.1 μs, using them one can get outstanding results in this area. This fact can be explained by the long period of luminophor persistence in intensifying X-ray luminescent screens. In this paper we present experimental data, comparing radiation doses, measured at pulse X-ray apparatus and apparatus of constant radiation.
文摘Use of Electronic gadgets such as mobile phones, computers/laptops constitutes an integral part of human day-to-day activity in offices and businesses. Therefore, their use cannot be stopped. These electronic gadgets emit electromagnetic radiations, which are believed to be hazardous to human health. World Health Organization/International Agency for Research on Cancer has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group B). The Enviro Chip developed by Synergy Environics, India, is a radiation harmonizing chip which when fixed on electronic gadgets at specific locations claims to reduce stress level by reducing the pulse rate of users which may also result in improvement of other health parameters. In this study, we have tested the ability of the Enviro Chip to reduce pulse rate of people who may have developed high pulse rate due to prolonged use of electronic gadgets. This was the double blind crossover study conducted in 205 healthy volunteers having an average pulse rate of above 82 per Minute at Max Healthcare India. The primary objective of the study was to evaluate and compare the change in pulse rate over 14 measurements with the use of both the Enviro Chip and a Dummy chip from average pulse rate at baseline without the Placebo effect. The secondary objective was to evaluate the change in pulse rate gender-wise. Data analysis was done using Wilcoxon Sign Rank test. The study demonstrated statistical significant reduction in pulse rate over 14 measurements with the use of Enviro Chip in both male and female healthy volunteers
文摘In this paper,we studied the effects of physical factors,such as,acoustic pulses of laser-induced hydrodynamics(ALIH)and extremely-high frequencies(EHF)radiation,on the formation of heterotopic bone marrow organs.A suspension of precipitated bone marrow cells from CBA mice were exposed to ALIH pulses and EHF radiation separately and in their com bination tissue engineering constructs,presenting gelatin sponges 2 by 2 by 2 mm in size containing 10^(7)nucleated bone marrow cells,were exposed to physical factors and were implanted under the renal capsules of syngeneic mice.The newly formed hematopoietic organs were examined in three and five months later after treatment.The five months old transplants were bigger in size than the three months old transplants.The number of hematopoietic cells in the rest of the groups increased during this period by a factor from 3 to 10,the increase being as high as 20-fold in the:ALH+EHF group.Maximal concentration of multipotent stromal cells(MSCs)was in the EHF+ALIH,and minimal concentration was in the ALIH+EHF.The accumulation rate of bone capsule weight was highest for the transplants of EHF+ALIH and ALIH-sponge groups during the first three months.These data showed that the combined impact of the EHF+ALIH on MSCs is the most effective for the formation of bone marrow transplantation.
基金supported by the National Natural Science Foundation of China(Nos.4210040255,U19A2086)the Sichuan Science and Technology Program(No.2021JDRC0108)。
文摘In this study,the anti-noise performance of a pulse-coupled neural network(PCNN)was investigated in the neutron and gamma-ray(n-γ)discrimination field.The experiments were conducted in two groups.In the first group,radiation pulse signals were pre-processed using a Fourier filter to reduce the original noise in the signals,whereas in the second group,the original noise was left untouched to simulate an extremely high-noise scenario.For each part,artificial Gaussian noise with different intensity levels was added to the signals prior to the discrimination process.In the aforementioned conditions,the performance of the PCNN was evaluated and compared with five other commonly used methods of n-γdiscrimination:(1)zero crossing,(2)charge comparison,(3)vector projection,(4)falling edge percentage slope,and(5)frequency gradient analysis.The experimental results showed that the PCNN method significantly outperforms other methods with outstanding FoM-value at all noise levels.Furthermore,the fluctuations in FoM-value of PCNN were significantly better than those obtained via other methods at most noise levels and only slightly worse than those obtained via the charge comparison and zerocrossing methods under extreme noise conditions.Additionally,the changing patterns and fluctuations of the FoMvalue were evaluated under different noise conditions.Hence,based on the results,the parameter selection strategy of the PCNN was presented.In conclusion,the PCNN method is suitable for use in high-noise application scenarios for n-γdiscrimination because of its stability and remarkable discrimination performance.It does not rely on strict parameter settings and can realize satisfactory performance over a wide parameter range.
文摘Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate (TMPTA) was incorporated into poly(ethylene terephthalate) (PET)/random terpolymer elastomer (ST2000) blends by melt-blending. The existence of TMPTA would induce the crosslinking of PET and ST2000 molecular chains at high temperatures of blend- ing, resulting in the improvement in the impact strength but the loss in the tensile strength. When the PET/ST2000 blends were irradiated by gamma-ray radiation, the integrated me- chanical properties could be enhanced significantly at a high absorbed dose. The irradiated sample at a dose of 100 kGy even couldn't be broken under the impact test load, and at the same time, has nearly no loss of tensile strength. Based on the analysis of the impact- fractured surface morphologies of the blends, it can be concluded that gamma-ray radiation at high absorbed dose can further in situ enhance the interfacial adhesion by promoting the crosslinking reactions of TMPTA and polymer chains. As a result, the toughness and strength of PET/ST2000 blend could be dramatically improved. This work provides a facial and practical way to the fabrication of polymer blends with high toughness and strength.
文摘Ultrawideband electromagnetic pulses with high amplitude and short duration are reported to affect several aspects of cell physiology. They are usually delivered to the living material through electrodes in small dedicated chambers. Here we showed, using a totally different experimental setup, that radiated EM pulses illuminating the living material through a specialized antenna (without any direct contact) are able to trigger a rapid release of ATP in cultured murine cells that was concomitant with a drop of intracellular AEC. Despite this rapid and strong response, we found that cell viability and clonogenicity were only slightly affected by the EMF exposure.
基金supported partly by the LHD project budget(NIFS15ULHH003 and NIFS15ULGG801)
文摘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.
基金supported by the Youth Innovations and Talents Project of Shandong Provincial Colleges and Universities(Grant No.201909118)the Natural Science Foundation(Grant Nos.ZR2018MA030,XKJJC201901 and OP201511)supported by a National Research Foundation of Korea Grant funded by the Korean government(NRF2018R1D1A3B070421880 and 2018R1A6A1A06024970)。
文摘Thanks to more and more gamma-ray bursts with measured redshift and extended emission detected by the recent space telescopes,it is urgent and possible to check whether those previous energy correlations still satisfy the particular sample involving only the bursts accompanied by tail radiations.Using 20 long and 22 short bursts with extended emission,we find that the popular γ-ray energy correlations of the intrinsic peak energy versus the isotropic energy(Amati relation) and the intrinsic peak energy versus the peak luminosity(Yonetoku relation) do exist in both short and long bursts.However,it is much better if these gamma-ray bursts with extended emissions are reclassified into two subgroups of E-Ⅰ and E-Ⅱ that make the above energy correlations more tight.As proposed by Zhang et al.,the energy correlations can be utilized to distinguish these kinds of gamma-ray bursts in the plane of bolometric fluence versus peak energy as well.Interestingly,the peculiar short GRB 170817 A belongs to the E-Ⅰ group in the fluence versus peak energy plane,but it is an outlier of both the Amati and Yonetoku relations even though the off-axis effect has been corrected.Furthermore,we compare the radiation features between the extended emissions and the prompt gamma-rays in order to search for their possible connections.Taking into account all these factors,we conclude that gamma-ray bursts with extended emission are still required to model with dichotomic groups,namely E-Ⅰ and E-Ⅱ classes,which hint that they might have different origins.
基金supported by the National Nature Science Foundation of China(Nos.11875191,11890714,11925502,11935001,and 11961141003)the Strategic Priority Research Program(No.CAS XDB1602)。
文摘With the development of laser technologies,nuclear reactions can happen in high-temperature plasma environments induced by lasers and have attracted a lot of attention from different physical disciplines.However,studies on nuclear reactions in plasma are still limited by detecting technologies.This is mainly due to the fact that extremely high electromagnetic pulses(EMPs)can also be induced when high-intensity lasers hit targets to induce plasma,and then cause dysfunction of many types of traditional detectors.Therefore,new particle detecting technologies are highly needed.In this paper,we report a recently developed gated fiber detector which can be used in harsh EMP environments.In this prototype detector,scintillating photons are coupled by fiber and then transferred to a gated photomultiplier tube which is located far away from the EMP source and shielded well.With those measures,the EMPs can be avoided which may result that the device has the capability to identify a single event of nuclear reaction products generated in laser-induced plasma from noise EMP backgrounds.This new type of detector can be widely used as a time-of-flight(TOF)detector in high-intensity laser nuclear physics experiments for detecting neutrons,photons,and other charged particles.
基金supported by the National Natural Science Foundation of China(Nos.11605163 and 21504085)the China Academy of Engineering Physics Foundation for Development of Science and Technology(No.201580103014 and No.2015B0301063)+1 种基金the Foundation for Special Talents in China Academy of Engineering Physics(No.TP201502-3)the Sichuan Science and Technology Development Foundation for Young Scientists(No.2017Q0050)
文摘Identifying the unknown geometric and material information of a multi-shield object by analyzing the radiation signature measurements is always an important problem in national and global security. In order to identify the unknown shielding layer thicknesses of a source/shield system with gamma-ray spectra, we have developed a derivative-free inverse radiation transport model based on a differential evolution algorithm with global and local neighbourhoods(IRT-DEGL). In the present paper, the IRT-DEGL model is further extended for estimating the unknown thicknesses with random initial guesses and material mass densities of multi-shielding layers as well as their combinations. Using the detected gamma-ray spectra,the illustration of inverse studies is implemented and the main influence factors for inverse results are also analyzed.
基金This project supported by the National Nature Science Foundation of China (No. 10035020 )
文摘Radiation simulation utilizing plasma radiation sources (PRS) generates a large number of undesirable debris, which may damage the expensive diagnosing detectors. An ultra fast shutter (UFS) driven by pulsed high current can erect a physical barrier to the slowly moving debris after allowing the passage of X-ray photons. The UFS consists of a pair of thin metal foils twisting the parallel axes in a Nylon cassette, compressed with an outer magnetic field, generated from a fast capacitor bank, discharging into a single turn loop. A typical capacitor bank is of 7.5μF charging voltages varying from 30 kV to 45 kV, with corresponding currents of approximately 90 kA to140 kA and discharging current periods of approximately 13.1μs. A shutter closing time as fast as 38 microseconds has been obtained with an aluminium foil thickness of 100 micrometers and a cross-sectional area of 15 mm by 20 mm. The design, construction and the expressions of the valve-closing time of the UFS are presented along with the measured results of valve-closing velocities.
基金Project supported by the National Natural Science Foundation of China(Grant No10574010)
文摘A Cherenkowtype terahertz electromagnetic radiation is revealed, which results efficiently from the collective effects in the time-domain of ultrafast pulsed electron current produced by ultrafast intense laser plasma interaction. The emitted pulse waveform and spectrum, and the dependence of laser pulse parameters on the structure of the radiation field are investigated numerically. The condition of THz radiation generation in this regime and Cherenkov geometry of the radiation field are studied analytically.
文摘An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and
基金Supported by the National Natural Science Foundation of China(41974127,41974155)China University of Petroleum(East China)Graduate Student Innovation Project Funding Project(YCX2020008)。
文摘A method is proposed to characterize the fast neutron scattering cross-section ( s f) quantitatively by the combina-tion of inelastic gamma rays and captured gamma rays, so as to realize the gas saturation evaluation of CO_(2)-injected heavy oilreservoirs based on the three-de tector pulsed neutron logging technology. Factors influencing of the evaluation effect of thismethod are analyzed and the effectiveness of this method is verified by a simulation example. By using the Monte Carlo simu-lation method and the physical model of bulk-volume rock, the relationship between s f and CO_(2) saturation is studied, and thesaturation interpretation model is established. The influences of formation temperature and pressure, heavy oil density, bore-hole fluid and reservoir methane content on the evaluation results of CO_(2) saturation are analyzed. The results show that thecharacterization of s f by the combination of secondary gamma information can eliminate the influence of formation lithology,borehole fluid and methane content are the main factors affecting the quantitative monitoring of CO_(2) saturation, and the ef-fects of formation temperature and pressure and heavy oil density are negligible. The simulation example verified the feasibilityof the method for evaluating the CO_(2) saturation of CO_(2)-injected heavy oil reservoirs.
文摘Objective:To investigate the clinical assessment of thyroid carcinoma in acoustic pulse radiation imaging and the correlation analysis of osteopontin expression.Methods: A total of 71 lesions of 60 patients with thyroid carcinoma (TC) in Hainan were selected. All patients were graded by TI-RADS grading and confirmed by pathology after operation. The expression of OPN was detected by immunohistochemical S-P method. The expression of OPN mRNA was detected by fluorescence quantitative polymerase chain reaction. The correlation between OPN expression and acoustic pulse radiation imaging was analyzed.Results:(1) 60 patients (93.33%) with primary TC and 4 (6.67%) patients with secondary TC were found in 60 patients with TC. Thirty-seven patients (61.67% according to the pathological features, 32 cases (53.33%) had papillary TC, diffuse sclerosis 19 cases of diffuse sclerosis PTC (31.67%), follicular carcinoma in 9 cases (15.00%). (2) The expression of OPN mRNA in 37 cases of calcified TC was significantly higher than that in non-calcified TC, and the increase of OPN expression was in direct proportion to the distribution of gritty calcification.Conclusions: The distribution of calcified microsomes in TC was positively correlated with the expression of OPN, suggesting that enhanced OPN expression may be related to the formation of psammoma bodies, the increased hardness of nodules and the increased malignancy. Acoustic pulse radiation imaging technology for early diagnosis of TC and prognosis of TC was of great significance.