The energy correlations of prompt fission neutrons have not yet been considered in the related coincidence and multiplication measurement techniques.To measure and verify the energy correlations,an experiment was perf...The energy correlations of prompt fission neutrons have not yet been considered in the related coincidence and multiplication measurement techniques.To measure and verify the energy correlations,an experiment was performed with a total measurement duration of approximately 1200 h.In the experiment,eight CLYC detectors and sixteen EJ309 liquid scintillation detectors were utilized,and the fission moment was tagged with the measured fissionγ-rays.The relative ratios of the energy spectra of the neutrons correlated with different energy neutrons to the^(252)Cf fission neutron energy spectra were obtained.The present results may be helpful for studying fission physics and nuclear technology applications.展开更多
Research on neutron-induced fission product yields of^(232)Th is crucial for understanding the competition between symmetric and asymmetric fission in actinide nuclei.However,obtaining complete isotopic yield distribu...Research on neutron-induced fission product yields of^(232)Th is crucial for understanding the competition between symmetric and asymmetric fission in actinide nuclei.However,obtaining complete isotopic yield distributions over a wide range of neutron energies remains a challenge.In this study,a Bayesian neural network model was developed to predict the independent(IND)and cumulative fission yields of^(232)Th under neutron irradiation at various incident energies.To address the limited availability of experimental data for the analysis of IND mass distributions,we substituted mass-number-based yields with the yields of specific isotopes.Furthermore,physical phenomena or quantities,such as the odd-even effect and isospin,were introduced as constraints to enhance the physical consistency of the predictions.The impact of these constraints was evaluated using mass-chain yield distributions and their dependence on energy.Incorporating physical constraints significantly improves the prediction accuracy,yielding more reliable and physically meaningful fission yield data for nuclear physics and reactor design applications.展开更多
The Jianghan Basin,at the junction of the Jiangnan and Qinling-Dabie orogenic belts,has a complete Cretaceous to Paleogene stratigraphic record.However,the exhumation history of its source terrains is not well underst...The Jianghan Basin,at the junction of the Jiangnan and Qinling-Dabie orogenic belts,has a complete Cretaceous to Paleogene stratigraphic record.However,the exhumation history of its source terrains is not well understood.We conducted fission track age analysis on zircon grains(n=441)from the Cretaceous and Paleogene strata in the western Jianghan Basin.The Radial Plotter software is utilized to identify peak ages that indicate thermal events and the history of exhumation.The oldest peak at 810 Ma records the Neoproterozoic collisional orogeny between the Yangtze Craton and Cathaysian Block.Ages of 645-558 Ma reflect the convergence between the South China Block and Gondwana.Early Paleozoic ages document the collision leading to the exhumation of the western Jiangnan Orogenic Belt.Late Paleozoic to early Mesozoic peak ages correspond to the Indosinian orogeny.During the Mesozoic,the subduction of the Paleo-Pacific Plate resulted in further exhumation.The absence of Paleogene zircon fission track peak ages in the basin strata suggests limited exhumation during this period,likely due to tectonic quiescence and arid climatic conditions.展开更多
Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl Riv...Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl River Mouth Basin(PRMB)were subjected to apatite and zircon fission track analyses,and suitable samples were selected for thermal history simulation using Hefty.The thermal history simulation results,combined with balanced cross-section analysis,constrain the Cenozoic tectonothermal history of the PRMB.The results indicate that the PRMB underwent differential uplift in the early Paleogene,followed by regional thermal subsidence in the late Paleogene.Subsequently,the PRMB began tectonic activation in the late Miocene due to the Dongsha movement,marked by two rapid cooling events of ca.11–6.5 and 6.5 Myr to the present.These cooling events are characterized by a gradual migration from east to west.The first rapid cooling event can be attributed to the NW-SE compressive stress field in the northeastern South China Sea,driven by the clockwise rotation of the Philippine Sea Plate during the late Miocene.The second rapid cooling event is linked to intensive arc-continental collision and the Taiwan Orogeny triggered by the rapid WNW-ward migration of the Philippine Sea Plate.展开更多
The giant impact hypothesis for the Moon's origin has had difficulty explaining the nearly identical isotopic compositions of Moon rocks and rocks from Earth's silicate mantle and crust.These similarities are ...The giant impact hypothesis for the Moon's origin has had difficulty explaining the nearly identical isotopic compositions of Moon rocks and rocks from Earth's silicate mantle and crust.These similarities are instead more compatible with the Darwin-Wise hypothesis that the Moon arose by fission of a rapidly spinning Earth.To overcome problems with the fission model concerning structural stability and angular momentum conservation,some authors suggested that lunar fission was feasible on a more slowly rotating Earth if assisted by a nuclear explosion near the core-mantle boundary.In this light we consider the possible roles of the large low-velocity provinces(LLVPs).These long-lived structures have been implicated in diverse geophysical processes ranging from deep mantle plumes to continental breakup and mass extinction events.While the LLVPs have been seen as possible remnants of the giant imp actor,we propose that one of them was the site of lunar ejection.Internal heating of the liquid core is suggested to have given rise to an equatorial belt just under the core-mantle boundary analogous to the one recently detected by Ma and Tkalcic[Sci Adv 10(35):eadn5562,2024].Upwellings of heat and volatiles from this belt then generated two antipodal,equatorial bulges:the precursors of the Pacific and African LLVPs.Prior to the emergence of plate tectonics,core heat was mainly dissipated by networks of deep mantle plumes extending above the proto-LLVPs.These plume networks represent conduits of weakened mantle through which proto-lunar materials could later rise in a focused ejection.Continuing heat buildup in the core eventually triggered a cataclysmic explosion in the Pacific proto-LLVP,possibly analogous to a planetary-scale kimberlite eruption.This explosion launched LLVP and overlying mantle material into a low Earth orbit,where it coalesced to form the Moon.Some possible sources of additional energy to power the explosion are considered,including nuclear fission,bolide impacts and a hypothetical gravitational decay process culminating in a'A event'.展开更多
The neutron richness of the light charged particles emitted out of the fission plane in heavy ion reactions has been experimentally investigated via the production of A=3 mirror nuclei in ^(86)Kr+^(nat)Pb reactions at...The neutron richness of the light charged particles emitted out of the fission plane in heavy ion reactions has been experimentally investigated via the production of A=3 mirror nuclei in ^(86)Kr+^(nat)Pb reactions at 25 MeV/u.The energy spectra and angular distributions of triton(t)and ^(3)He in coincidence with two fission fragments are measured with the Compact Spectrometer for Heavy IoN Experiment(CSHINE).The energy spectrum of ^(3)He is observed harder than that of triton in the fission events,in accordance with the phenomena reported as“^(3)He-puzzle”in inclusive measurements.With a data-driven energy spectrum peak cut scenario,it is observed that the yield ratio R(t∕^(3)He)increases with the angle to the fission plane,showing an enhancement of neutron-rich particle emission from out-of-fission-plane.A qualitative comparison with the transport model calculations suggests that this observation may serve as a new probe for the nuclear symmetry energy.展开更多
The internal pressure within fission gas bubbles(FGBs)in irradiated nuclear fuels drives mechanical interactions with the surrounding fuel skeleton.To investigate the micromechanical stress fields in irradiated nuclea...The internal pressure within fission gas bubbles(FGBs)in irradiated nuclear fuels drives mechanical interactions with the surrounding fuel skeleton.To investigate the micromechanical stress fields in irradiated nuclear fuels containing pressurized FGBs,a mechanical constitutive model for the equivalent solid of FGBs was developed and validated.This model was based on the modified Van der Waals equation,incorporating the effects of surface tension.Using this model,the micromechanical fields in irradiated U-10Mo fuels with randomly distributed FGBs were calculated during uniaxial tensile testing via the finite element(FE)method.The macroscopic elastic constants of the irradiated U-10Mo fuels were then derived using homogenization theory,and the influences of bubble pressure,bubble size,and porosity on these constants were examined.Results show that adjacent FGBs exhibit mechanical interactions,which leads to distinct stress concentrations in the surrounding fuel skeleton.The macroscopic elastic constants of irradiated U-10Mo fuels decrease with increasing the macroscopic porosity,which can be quantitatively described by the Mori-Tanaka model.In contrast,bubble pressure and size have negligible effects on these constants.展开更多
In this study,the fission properties of^(180)Hg were investigated based on Skyrme density functional theory.The impact of the high-order hexadecapole moment(q_(40))was observed at large deformations.With the q_(40)con...In this study,the fission properties of^(180)Hg were investigated based on Skyrme density functional theory.The impact of the high-order hexadecapole moment(q_(40))was observed at large deformations.With the q_(40)constraint,smooth and continuous potential energy surfaces could be obtained.In particular,the hexadecapole moment constraint is essential for obtaining appropriate scission configurations.The static fission path based on the PES supports the asymmetric fission of^(180)Hg.The asymmetric distribution of the fission yields of^(180)Hg was reproduced by the time-dependent generator coordinate method and agreed well with the experimental data.展开更多
The Yangchuling porphyry W-Mo deposit(YPWD),located in the Jiangnan porphyryskarn tungsten ore belt,is one of the most important and large-scale porphyry W-Mo deposits in South China.While previous zircon U-Pb and mol...The Yangchuling porphyry W-Mo deposit(YPWD),located in the Jiangnan porphyryskarn tungsten ore belt,is one of the most important and large-scale porphyry W-Mo deposits in South China.While previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling WMo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at~150–144 Ma,their post emplacement history remains poorly understood,making their preservation status at depth uncertain.In this paper,new zircon and apatite(U-Th)/He and apatite fission track(ZHe,AHe and AFT,respectively)data of one hornfels and five intrusive rocks from a 1000-meter borehole are presented.These,together with new inverse thermal history models and previous geochronological data,help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo deposit.In general,ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation,ranging from 133 to 73Ma and 67 to 25 Ma,respectively.All four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2±0.7 to 12.6±0.5μm.Thermal history modelling indicates that the Yangchuling ore district experienced slow,monotonic cooling since the Cretaceous.Age-depth relationships are interpreted as recording~3.7±0.8 km of Cretaceous-recent exhumation in response to regional extension throughout South China thought to have been driven by subduction retreat of the Paleo-Pacific Plate.Comparison of estimated net exhumation and previous metallogenic depth of~4–5 km suggests that W-Mo ore bodies could still exist at depths of up to~1.3±0.8 km relative to Earth surface in the YPWD region.Preservation of the YPWD is attributed to the limited amount of regional denudation during the Late Cretaceous and Cenozoic.展开更多
Intervertebral disc degeneration(IVDD)is the primary contributor to a range of spinal diseases.Dynamin-related protein 1(Drp1)-mediated mitochondrial fission has recently been identified as a new cause of nucleus pulp...Intervertebral disc degeneration(IVDD)is the primary contributor to a range of spinal diseases.Dynamin-related protein 1(Drp1)-mediated mitochondrial fission has recently been identified as a new cause of nucleus pulposus cell(NPC)death and IVDD,but the underlying mechanisms remain unclear.Although the effects of Drp1 phosphorylation in IVDD have been studied,it is currently unknown if small ubiquitin-like modifications(SUMOylation)of Drp1 regulate IVDD.This study aimed to investigate the functions and mechanisms of mitochondria-anchored protein ligase(MAPL),a mitochondrial SUMO E3 ligase,during IVDD progression.The expression of genes related to SUMOylation and mitochondrial dynamics in TNF-α-stimulated NPCs was analysed via RNA sequencing.展开更多
Prompt fission neutron spectra(PFNS)have a significant role in nuclear science and technology.In this study,the PFNS for^(239)Pu are evaluated using both differential and integral experimental data.A method that lever...Prompt fission neutron spectra(PFNS)have a significant role in nuclear science and technology.In this study,the PFNS for^(239)Pu are evaluated using both differential and integral experimental data.A method that leverages integral criticality benchmark experiments to constrain the PFNS data is introduced.The measured central values of the PFNS are perturbed by constructing a covariance matrix.The PFNS are sampled using two types of covariance matrices,either generated with an assumed correlation matrix and incorporating experimental uncertainties or derived directly from experimental reports.The joint Monte Carlo transport code is employed to perform transport simulations on five criticality benchmark assemblies by utilizing perturbed PFNS data.Extensive simulations result in an optimized PFNS that shows improved agreement with the integral criticality benchmark experiments.This study introduces a novel approach for optimizing differential experimental data through integral experiments,particularly when a covariance matrix is not provided.展开更多
The temporal and spatial evolution of the Ailao Shan-Red River(ASRR)fault zone,which serves as an important accommodation zone for the extrusion and escape of the Southeastern Tibetan Plateau,is crucial for analyzing ...The temporal and spatial evolution of the Ailao Shan-Red River(ASRR)fault zone,which serves as an important accommodation zone for the extrusion and escape of the Southeastern Tibetan Plateau,is crucial for analyzing the uplift and growth of the plateau.Based on the petrology and apatite fission track analysis,the tectonic history and active pattern of the ASRR fault zone since the middle Miocene are determined in this study.The ASRR fault zone exhibits 12-8Ma and 8-4 Ma rapid cooling phases since the middle Miocene.The 12-8 Ma and 8-4 Ma cooling may imply that the dextral movement of the ASRR fault zone presents a migration trend from northwest to southeast,accompanied by the weakening of the activity intensity,which is directly related to deformation processes,including extrusion boundary migration and active tectonic movements of the southeastern Tibetan Plateau,since the middle-late Miocene.展开更多
Polycystic ovarian syndrome(PCOS)is the most principal reason for infertility in reproductive women,but no versatile treatment is feasible.Although trans-10-hydroxy-2-decenoic acid(10H2DA)exhibits the anti-inflammator...Polycystic ovarian syndrome(PCOS)is the most principal reason for infertility in reproductive women,but no versatile treatment is feasible.Although trans-10-hydroxy-2-decenoic acid(10H2DA)exhibits the anti-inflammatory,anti-cancerous and immunomodulatory properties,its role in improving PCOS remains elusive.This present study examined the effects of 10H2DA on the estrous cycle,ovarian morphology,reproductive hormone,glucose and insulin tolerances of PCOS mice,analyzed the binding between 10H2DA and free fatty acid receptor 4(FFAR4),and explored the regulation of 10H2DA on the c-Jun N-terminal kinase(JNK)/JUN(Jun proto-oncogene)signaling,cytosolic calcium ion(Ca^(2+)),endoplasmic reticulum(ER)Ca^(2+) release,mitochondrial Ca^(2+),mitochondrial function,autophagy,lysosomal acidification,mitochondrial fission,secretion function and apoptosis of ovarian granulosa cells(GCs)using enzyme-linked immunosorbent assay,flow cytometry,Western blotting,molecular docking,various fluorescent probes or plasmid,etc.The results showed that 10H2DA alleviated the symptom of PCOS mice through improving the secretion dysfunction of GCs and protecting GCs against apoptosis.After binding to FFAR4 and inactivation of JNK/JUN signaling,10H2DA restricted the release of ER Ca^(2+)through targeting ryanodine receptors(RYRs)which had been identified as the downstream targets of JUN,diminished cytosolic Ca^(2+) accumulation and prevented Ca^(2+) influx into mitochondria via adjusting the mitochondrial calcium uptake 1 and mitochondrial calcium uniporter.Concurrently,10H2DA kept the integrity of mitochondrial function through maintaining mitochondrial Ca2 homeostasis and suppressed the discharge of mitochondrial reactive oxygen species into the cytosol through blocking the mitochondrial permeability transition pore opening to avoid the lipid peroxidation and ameliorate the secretory function and apoptosis of GCs.Furthermore,1OH2DA rescued the defective autophagic flux along with the decline of autophagosomes and sequestosome 1 aggregation,restored the mitophagy flux with the abatement of mitophagosomes and Parkin recruitment to mitochondria,and accelerated the lysosomal degradation for depolarized mitochondria with the recovery of lysosomal acidification,whereas activation of JNK antagonized the amelioration of 10H2DA on above effectiveness,but this antagonism was counteracted by the attenuation of intracellular Ca^(2+).After application of 10H2DA,dynamin-related protein 1 phosphorylation was diminished and its recruitment to mitochondrial surface was impeded concomitant with the improvement of mitochondrial fragmentation,whereas inhibition of late-stage autophagy caused the failure of 10H2DA in improving mitochondrial fission.Collectively,10H2DA might ameliorate PCOS mice through modulating autophagy-mediated mitochondrial fission dependent on the maintenance of Ca^(2+) homeostasis between ER and mitochondria.展开更多
We studied the energy partition between two well-separated fission fragments associated with the partition of nucleons owing to quantum entanglement.This is different from most fission models that invoke an explicit s...We studied the energy partition between two well-separated fission fragments associated with the partition of nucleons owing to quantum entanglement.This is different from most fission models that invoke an explicit statistical partition of excitation energies.The dynamical fission evolution is described within the time-dependent Hartree-Fock+BCS framework.Excitation energies of isotopic fission fragments were obtained using the particle number projection method after the dynamical splitting of^(238)U.The resulting excitation energies of the light and heavy fragments are consistent with the appearance of sawtooth structures.We found that the pairing correlation strengths have a significant influence on the partition of the excitation energies.Furthermore,the excitation energies of isotopic fragments increase with increasing neutron number,implying the suppression of the production of neutron-rich beams in rare-isotope beam facilities.展开更多
BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an imp...BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an important mechanism of DCD.Blocking calcium overload and restoring calcium homeostasis are key steps in treatment.Transient receptor potential melastatin 7(TRPM7)is a novel player in causing calcium overload.Our previous studies have shown that genetic silencing of TRPM7 in type 1 diabetic rats leads to significant improvements in cognitive function,but the specific mechanism remains unclear.Troxerutin,extracted from the flowers of Sophora japonica,is one of the derivatives of rutin and has been shown to have neuroprotective effects.However,its association with TRPM7 remains unclear.AIM To use animal and cellular models,we investigated whether TRPM7 mediated mitochondrial fission by upregulation of calcineurin(CaN)/dynamin-related protein 1(Drp1)ser637 in DCD,and whether Troxerutin improved DCD by inhibiting TRPM7-mediated mitochondrial division.METHODS In this study,we used db/db mice and hippocampal neuronal cell lines(HT22)treated with high-concentration glucose as our study subjects.We evaluated cognitive function using Morris water maze,novel object recognition tasks,and Nesting tests.We observed mitochondrial morphology using transmission electron microscopy and measured mitochondrial energy metabolism indicators using a spectrophotometer.We also detected mRNA and protein expression of TRPM7,CaN,p-Drp1^(ser637),caspase-3,B-cell lymphoma 2 associated X protein,and B-cell lymphoma 2 using quantitative real-time polymerase chain reaction,western blotting,and immunofluorescence.RESULTS In the db/db diabetic mice with cognitive dysfunction,as well as in hippocampal neurons exposed to high-concentration glucose,TRPM7 and CaN expression were upregulated,phosphorylated Drp1^(ser637)expression was downregulated,and mitochondrial fission was increased.By modulating(inhibiting or overexpressing)TRPM7,it was further validated that TRPM7 activates the CaN/Drp1^(ser637)pathway,resulting in an increase in mitochondrial fission and neuronal cell apoptosis.Troxerutin downregulated TRPM7/CaN/Drp1^(ser637),reduced mitochondrial fission,and improved DCD.CONCLUSION TRPM7 promotes mitochondrial fission via the CaN/Drp1^(ser637)pathway.Troxerutin improves mitochondrial function and reduces neuronal damage by inhibiting this pathway,suggesting TRPM7 as a potential therapeutic target for DCD.展开更多
Photofission fragments mass yield for^(232)Th,^(234;238) U,^(237) Np, and^(239;240;242) Pu isotopes are investigated.The calculations are done using a developed approach based on Gorodisskiy's phenomenological for...Photofission fragments mass yield for^(232)Th,^(234;238) U,^(237) Np, and^(239;240;242) Pu isotopes are investigated.The calculations are done using a developed approach based on Gorodisskiy's phenomenological formalism. The Gorodisskiy's method is developed to be applied for the neutron-induced fission. Here we revised it for application to photofission. The effect of emitted neutron prior to fission on the fission fragment mass yields has also been studied. The peak-to-valley ratio is extracted for the240 Pu isotope as a function of energy. Obtained results of the present formalism are compared with the available experimental data. Satisfactory agreement is achieved between the results of present approach and the experimental data.展开更多
Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pair...Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pairing forces,as well as a combination of these two forces,were used for the Hartree–Fock–Bogoliubov approximation.Variations in the least-energy fission path,fission barrier,pairing energy,total kinetic energy,scission line,and mass distribution of the fission fragments based on the different forms of the pairing forces were analyzed and discussed.The fission dynamics were studied based on the timedependent generator coordinate method plus the Gaussian overlap approximation.The results demonstrated a sensitivity of the mass and charge distributions of the fission fragments on the form of the pairing force.Based on the investigation of the neutron-induced fission of^(239)Pu,among the volume,mixed,and surface pairing forces,the mixed pairing force presented a good reproduction of the experimental data.展开更多
Photofission enables a unique capability for the domain of non-chemical space propulsion. An ultra-intense laser enables the capacity to induce nuclear fission through the development of bre- msstrahlung photons. A fu...Photofission enables a unique capability for the domain of non-chemical space propulsion. An ultra-intense laser enables the capacity to induce nuclear fission through the development of bre- msstrahlung photons. A fundamental architecture and performance analysis of a photofission pulsed space propulsion system through the operation of an ultra-intense laser is presented. A historical perspective of previous conceptual nuclear fission propulsion systems is addressed. These applications use neutron derived nuclear fission;however, there is inherent complexity that has precluded further development. The background of photofission is detailed. The conceptual architecture of photofission pulsed space propulsion and fundamental performance parameters are established. The implications are the energy source and ultra-intense laser can be situated far remote from the propulsion system. Advances in supporting laser technologies are anticipated to increase the potential for photofission pulsed space propulsion. The fundamental performance analysis of the photofission pulsed space propulsion system indicates the architecture is feasible for further evaluation.展开更多
The studies of thermal fission rates are relevant to novel reactors,astrophysical environments,and survival probabilities of compound superheavy nuclei.This has been conventionally studied by the Bohr-Wheeler statisti...The studies of thermal fission rates are relevant to novel reactors,astrophysical environments,and survival probabilities of compound superheavy nuclei.This has been conventionally studied by the Bohr-Wheeler statistical model that depends on phenomenological level densities and fission barriers.In this context,we propose to study the thermal fission rates based on microscopic temperature dependent nuclear energy density functional theory.The microscopic temperature dependent fission barrier heights and curvatures,and collective mass parameters can be self-consistently obtained.The fission lifetimes from low to high temperatures can be given by the imaginary free energy method in a consistent framework.Microscopic temperature dependent fission barriers play an essential role in fission studies.展开更多
Project New Orion entails a pulsed nuclear space propulsion system that utilizes photofission through the implementation of an ultra-intense laser. The historical origins derive from the endeavors of Project Orion, wh...Project New Orion entails a pulsed nuclear space propulsion system that utilizes photofission through the implementation of an ultra-intense laser. The historical origins derive from the endeavors of Project Orion, which utilized thermonuclear devices to impart a considerable velocity increment on the respective spacecraft. The shear magnitude of Project Orion significantly detracts from the likelihood of progressive research development testing and evaluation. Project New Orion incorporates a more feasible pathway for the progressive research development testing and evaluation of the pulsed nuclear space propulsion system. Photofission through the application of an ultra-intense laser enables a much more controllable and scalable nuclear yield. The energy source for the ultra-intense laser is derived from a first stage liquid hydrogen and liquid oxygen chemical propulsion system. A portion of the thermal/kinetic energy of the rocket propulsive fluid is converted to electrical energy through a magneto-hydrodynamic generator with cryogenic propellant densification for facilitating the integral superconducting magnets. Fundamental analysis of Project New Orion demonstrates the capacity to impart a meaningful velocity increment through ultra-intense laser derived photofission on a small spacecraft.展开更多
基金supported by the National Natural Science Foundation of China(No.12105257)the Research and Development Fund(No.JMJJ202401)。
文摘The energy correlations of prompt fission neutrons have not yet been considered in the related coincidence and multiplication measurement techniques.To measure and verify the energy correlations,an experiment was performed with a total measurement duration of approximately 1200 h.In the experiment,eight CLYC detectors and sixteen EJ309 liquid scintillation detectors were utilized,and the fission moment was tagged with the measured fissionγ-rays.The relative ratios of the energy spectra of the neutrons correlated with different energy neutrons to the^(252)Cf fission neutron energy spectra were obtained.The present results may be helpful for studying fission physics and nuclear technology applications.
基金supported by the National Natural Science Foundation of China(Nos.12247126 and 12375123)Henan Postdoctoral Foundation(No.HN2024013)the Natural Science Foundation of Henan Province(No.242300421048)。
文摘Research on neutron-induced fission product yields of^(232)Th is crucial for understanding the competition between symmetric and asymmetric fission in actinide nuclei.However,obtaining complete isotopic yield distributions over a wide range of neutron energies remains a challenge.In this study,a Bayesian neural network model was developed to predict the independent(IND)and cumulative fission yields of^(232)Th under neutron irradiation at various incident energies.To address the limited availability of experimental data for the analysis of IND mass distributions,we substituted mass-number-based yields with the yields of specific isotopes.Furthermore,physical phenomena or quantities,such as the odd-even effect and isospin,were introduced as constraints to enhance the physical consistency of the predictions.The impact of these constraints was evaluated using mass-chain yield distributions and their dependence on energy.Incorporating physical constraints significantly improves the prediction accuracy,yielding more reliable and physically meaningful fission yield data for nuclear physics and reactor design applications.
基金the financial support provided by the National Natural Science Foundation of China(Grant No.41972212)the Hubei Chutian Scholars Talent Program(Grant No.8210403)。
文摘The Jianghan Basin,at the junction of the Jiangnan and Qinling-Dabie orogenic belts,has a complete Cretaceous to Paleogene stratigraphic record.However,the exhumation history of its source terrains is not well understood.We conducted fission track age analysis on zircon grains(n=441)from the Cretaceous and Paleogene strata in the western Jianghan Basin.The Radial Plotter software is utilized to identify peak ages that indicate thermal events and the history of exhumation.The oldest peak at 810 Ma records the Neoproterozoic collisional orogeny between the Yangtze Craton and Cathaysian Block.Ages of 645-558 Ma reflect the convergence between the South China Block and Gondwana.Early Paleozoic ages document the collision leading to the exhumation of the western Jiangnan Orogenic Belt.Late Paleozoic to early Mesozoic peak ages correspond to the Indosinian orogeny.During the Mesozoic,the subduction of the Paleo-Pacific Plate resulted in further exhumation.The absence of Paleogene zircon fission track peak ages in the basin strata suggests limited exhumation during this period,likely due to tectonic quiescence and arid climatic conditions.
基金funded by the National Natural Science Foundation of China(Nos.42121005,92358302,42302233)the Science and Technology Innovation Project of Laoshan Laboratory(No.LSKJ202204400)the Fundamental Research Funds for the Central Universities(No.202172003)。
文摘Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl River Mouth Basin(PRMB)were subjected to apatite and zircon fission track analyses,and suitable samples were selected for thermal history simulation using Hefty.The thermal history simulation results,combined with balanced cross-section analysis,constrain the Cenozoic tectonothermal history of the PRMB.The results indicate that the PRMB underwent differential uplift in the early Paleogene,followed by regional thermal subsidence in the late Paleogene.Subsequently,the PRMB began tectonic activation in the late Miocene due to the Dongsha movement,marked by two rapid cooling events of ca.11–6.5 and 6.5 Myr to the present.These cooling events are characterized by a gradual migration from east to west.The first rapid cooling event can be attributed to the NW-SE compressive stress field in the northeastern South China Sea,driven by the clockwise rotation of the Philippine Sea Plate during the late Miocene.The second rapid cooling event is linked to intensive arc-continental collision and the Taiwan Orogeny triggered by the rapid WNW-ward migration of the Philippine Sea Plate.
文摘The giant impact hypothesis for the Moon's origin has had difficulty explaining the nearly identical isotopic compositions of Moon rocks and rocks from Earth's silicate mantle and crust.These similarities are instead more compatible with the Darwin-Wise hypothesis that the Moon arose by fission of a rapidly spinning Earth.To overcome problems with the fission model concerning structural stability and angular momentum conservation,some authors suggested that lunar fission was feasible on a more slowly rotating Earth if assisted by a nuclear explosion near the core-mantle boundary.In this light we consider the possible roles of the large low-velocity provinces(LLVPs).These long-lived structures have been implicated in diverse geophysical processes ranging from deep mantle plumes to continental breakup and mass extinction events.While the LLVPs have been seen as possible remnants of the giant imp actor,we propose that one of them was the site of lunar ejection.Internal heating of the liquid core is suggested to have given rise to an equatorial belt just under the core-mantle boundary analogous to the one recently detected by Ma and Tkalcic[Sci Adv 10(35):eadn5562,2024].Upwellings of heat and volatiles from this belt then generated two antipodal,equatorial bulges:the precursors of the Pacific and African LLVPs.Prior to the emergence of plate tectonics,core heat was mainly dissipated by networks of deep mantle plumes extending above the proto-LLVPs.These plume networks represent conduits of weakened mantle through which proto-lunar materials could later rise in a focused ejection.Continuing heat buildup in the core eventually triggered a cataclysmic explosion in the Pacific proto-LLVP,possibly analogous to a planetary-scale kimberlite eruption.This explosion launched LLVP and overlying mantle material into a low Earth orbit,where it coalesced to form the Moon.Some possible sources of additional energy to power the explosion are considered,including nuclear fission,bolide impacts and a hypothetical gravitational decay process culminating in a'A event'.
基金the National Natural Science Foundation of China(Nos.12205160,11961131010,11961141004,and 11965004)by the Ministry of Science and Technology of China(Nos.2022YFE0103400 and 2020YFE0202001)+2 种基金by the Polish National Science Center(No.2023/49/B/ST2/01294)This work is also supported by Initiative Scientific Research Program and the Center of High Performance Computing of Tsinghua Universitythe Heavy Ion Research Facility at Lanzhou(HIRFL).
文摘The neutron richness of the light charged particles emitted out of the fission plane in heavy ion reactions has been experimentally investigated via the production of A=3 mirror nuclei in ^(86)Kr+^(nat)Pb reactions at 25 MeV/u.The energy spectra and angular distributions of triton(t)and ^(3)He in coincidence with two fission fragments are measured with the Compact Spectrometer for Heavy IoN Experiment(CSHINE).The energy spectrum of ^(3)He is observed harder than that of triton in the fission events,in accordance with the phenomena reported as“^(3)He-puzzle”in inclusive measurements.With a data-driven energy spectrum peak cut scenario,it is observed that the yield ratio R(t∕^(3)He)increases with the angle to the fission plane,showing an enhancement of neutron-rich particle emission from out-of-fission-plane.A qualitative comparison with the transport model calculations suggests that this observation may serve as a new probe for the nuclear symmetry energy.
基金National Natural Science Foundation of China(12135008,12132005)。
文摘The internal pressure within fission gas bubbles(FGBs)in irradiated nuclear fuels drives mechanical interactions with the surrounding fuel skeleton.To investigate the micromechanical stress fields in irradiated nuclear fuels containing pressurized FGBs,a mechanical constitutive model for the equivalent solid of FGBs was developed and validated.This model was based on the modified Van der Waals equation,incorporating the effects of surface tension.Using this model,the micromechanical fields in irradiated U-10Mo fuels with randomly distributed FGBs were calculated during uniaxial tensile testing via the finite element(FE)method.The macroscopic elastic constants of the irradiated U-10Mo fuels were then derived using homogenization theory,and the influences of bubble pressure,bubble size,and porosity on these constants were examined.Results show that adjacent FGBs exhibit mechanical interactions,which leads to distinct stress concentrations in the surrounding fuel skeleton.The macroscopic elastic constants of irradiated U-10Mo fuels decrease with increasing the macroscopic porosity,which can be quantitatively described by the Mori-Tanaka model.In contrast,bubble pressure and size have negligible effects on these constants.
基金supported by the National Key R and D Program of China(No.2022YFA1602000)National Natural Science Foundation of China(Nos.12275081 and U1732138)Continuous-support Basic Scientific Research Project.
文摘In this study,the fission properties of^(180)Hg were investigated based on Skyrme density functional theory.The impact of the high-order hexadecapole moment(q_(40))was observed at large deformations.With the q_(40)constraint,smooth and continuous potential energy surfaces could be obtained.In particular,the hexadecapole moment constraint is essential for obtaining appropriate scission configurations.The static fission path based on the PES supports the asymmetric fission of^(180)Hg.The asymmetric distribution of the fission yields of^(180)Hg was reproduced by the time-dependent generator coordinate method and agreed well with the experimental data.
基金supported by the National Natural Science Foundation of China(Nos.42162013,42002095)the Foundation of State Key Laboratory of Nuclear Resources and Environment(Nos.2022NRE34,NRE2021-01)+1 种基金Jiangxi Provincial Natural Science Foundation(Nos.20242BAB26048,20242BAB25178)Fund of National Key Laboratory of Science and Technology on Remote Sensing Information and imagery Analysis,Beijing Research Institute of Uranium Geology(No.6142A01210405)。
文摘The Yangchuling porphyry W-Mo deposit(YPWD),located in the Jiangnan porphyryskarn tungsten ore belt,is one of the most important and large-scale porphyry W-Mo deposits in South China.While previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling WMo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at~150–144 Ma,their post emplacement history remains poorly understood,making their preservation status at depth uncertain.In this paper,new zircon and apatite(U-Th)/He and apatite fission track(ZHe,AHe and AFT,respectively)data of one hornfels and five intrusive rocks from a 1000-meter borehole are presented.These,together with new inverse thermal history models and previous geochronological data,help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo deposit.In general,ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation,ranging from 133 to 73Ma and 67 to 25 Ma,respectively.All four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2±0.7 to 12.6±0.5μm.Thermal history modelling indicates that the Yangchuling ore district experienced slow,monotonic cooling since the Cretaceous.Age-depth relationships are interpreted as recording~3.7±0.8 km of Cretaceous-recent exhumation in response to regional extension throughout South China thought to have been driven by subduction retreat of the Paleo-Pacific Plate.Comparison of estimated net exhumation and previous metallogenic depth of~4–5 km suggests that W-Mo ore bodies could still exist at depths of up to~1.3±0.8 km relative to Earth surface in the YPWD region.Preservation of the YPWD is attributed to the limited amount of regional denudation during the Late Cretaceous and Cenozoic.
基金supported by National Natural Science Foundation of China(82272549,82472505,and 82472498)National key Research and Development plan,Ministry of Science and Technology of the People’s Republic of China(2022YFC2407203)+2 种基金the Young Health Talents of Shanghai Municipal Health Commission,China(2022YQ011)China Medical Education Association(3030537245)The Youth Talent Project of Huashan Hospital(30302164006).
文摘Intervertebral disc degeneration(IVDD)is the primary contributor to a range of spinal diseases.Dynamin-related protein 1(Drp1)-mediated mitochondrial fission has recently been identified as a new cause of nucleus pulposus cell(NPC)death and IVDD,but the underlying mechanisms remain unclear.Although the effects of Drp1 phosphorylation in IVDD have been studied,it is currently unknown if small ubiquitin-like modifications(SUMOylation)of Drp1 regulate IVDD.This study aimed to investigate the functions and mechanisms of mitochondria-anchored protein ligase(MAPL),a mitochondrial SUMO E3 ligase,during IVDD progression.The expression of genes related to SUMOylation and mitochondrial dynamics in TNF-α-stimulated NPCs was analysed via RNA sequencing.
基金supported by the National Natural Science Foundation of China(No.12347126)。
文摘Prompt fission neutron spectra(PFNS)have a significant role in nuclear science and technology.In this study,the PFNS for^(239)Pu are evaluated using both differential and integral experimental data.A method that leverages integral criticality benchmark experiments to constrain the PFNS data is introduced.The measured central values of the PFNS are perturbed by constructing a covariance matrix.The PFNS are sampled using two types of covariance matrices,either generated with an assumed correlation matrix and incorporating experimental uncertainties or derived directly from experimental reports.The joint Monte Carlo transport code is employed to perform transport simulations on five criticality benchmark assemblies by utilizing perturbed PFNS data.Extensive simulations result in an optimized PFNS that shows improved agreement with the integral criticality benchmark experiments.This study introduces a novel approach for optimizing differential experimental data through integral experiments,particularly when a covariance matrix is not provided.
基金supported by the National Natural Science Foundation of China(Grant Nos.41530963,42406077)the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2022QD087)the National Natural Science Foundation of China(Grant Nos.42376060,41176038)。
文摘The temporal and spatial evolution of the Ailao Shan-Red River(ASRR)fault zone,which serves as an important accommodation zone for the extrusion and escape of the Southeastern Tibetan Plateau,is crucial for analyzing the uplift and growth of the plateau.Based on the petrology and apatite fission track analysis,the tectonic history and active pattern of the ASRR fault zone since the middle Miocene are determined in this study.The ASRR fault zone exhibits 12-8Ma and 8-4 Ma rapid cooling phases since the middle Miocene.The 12-8 Ma and 8-4 Ma cooling may imply that the dextral movement of the ASRR fault zone presents a migration trend from northwest to southeast,accompanied by the weakening of the activity intensity,which is directly related to deformation processes,including extrusion boundary migration and active tectonic movements of the southeastern Tibetan Plateau,since the middle-late Miocene.
基金supported by Natural Science Foundation of Jilin Province(20220101287JC)National Natural Science Foundation of China(31873003 and 31472158)Graduate Innovation Fund of Jilin University(2022140).
文摘Polycystic ovarian syndrome(PCOS)is the most principal reason for infertility in reproductive women,but no versatile treatment is feasible.Although trans-10-hydroxy-2-decenoic acid(10H2DA)exhibits the anti-inflammatory,anti-cancerous and immunomodulatory properties,its role in improving PCOS remains elusive.This present study examined the effects of 10H2DA on the estrous cycle,ovarian morphology,reproductive hormone,glucose and insulin tolerances of PCOS mice,analyzed the binding between 10H2DA and free fatty acid receptor 4(FFAR4),and explored the regulation of 10H2DA on the c-Jun N-terminal kinase(JNK)/JUN(Jun proto-oncogene)signaling,cytosolic calcium ion(Ca^(2+)),endoplasmic reticulum(ER)Ca^(2+) release,mitochondrial Ca^(2+),mitochondrial function,autophagy,lysosomal acidification,mitochondrial fission,secretion function and apoptosis of ovarian granulosa cells(GCs)using enzyme-linked immunosorbent assay,flow cytometry,Western blotting,molecular docking,various fluorescent probes or plasmid,etc.The results showed that 10H2DA alleviated the symptom of PCOS mice through improving the secretion dysfunction of GCs and protecting GCs against apoptosis.After binding to FFAR4 and inactivation of JNK/JUN signaling,10H2DA restricted the release of ER Ca^(2+)through targeting ryanodine receptors(RYRs)which had been identified as the downstream targets of JUN,diminished cytosolic Ca^(2+) accumulation and prevented Ca^(2+) influx into mitochondria via adjusting the mitochondrial calcium uptake 1 and mitochondrial calcium uniporter.Concurrently,10H2DA kept the integrity of mitochondrial function through maintaining mitochondrial Ca2 homeostasis and suppressed the discharge of mitochondrial reactive oxygen species into the cytosol through blocking the mitochondrial permeability transition pore opening to avoid the lipid peroxidation and ameliorate the secretory function and apoptosis of GCs.Furthermore,1OH2DA rescued the defective autophagic flux along with the decline of autophagosomes and sequestosome 1 aggregation,restored the mitophagy flux with the abatement of mitophagosomes and Parkin recruitment to mitochondria,and accelerated the lysosomal degradation for depolarized mitochondria with the recovery of lysosomal acidification,whereas activation of JNK antagonized the amelioration of 10H2DA on above effectiveness,but this antagonism was counteracted by the attenuation of intracellular Ca^(2+).After application of 10H2DA,dynamin-related protein 1 phosphorylation was diminished and its recruitment to mitochondrial surface was impeded concomitant with the improvement of mitochondrial fragmentation,whereas inhibition of late-stage autophagy caused the failure of 10H2DA in improving mitochondrial fission.Collectively,10H2DA might ameliorate PCOS mice through modulating autophagy-mediated mitochondrial fission dependent on the maintenance of Ca^(2+) homeostasis between ER and mitochondria.
基金supported by the National Key R&D Program of China(Nos.2023YFE0101500,2023YFA1606403)the National Natural Science Foundation of China(Nos.12475118,12335007)the State Key Laboratory of Nuclear Physics and Technology,Peking University(No.NPT2023ZX01)。
文摘We studied the energy partition between two well-separated fission fragments associated with the partition of nucleons owing to quantum entanglement.This is different from most fission models that invoke an explicit statistical partition of excitation energies.The dynamical fission evolution is described within the time-dependent Hartree-Fock+BCS framework.Excitation energies of isotopic fission fragments were obtained using the particle number projection method after the dynamical splitting of^(238)U.The resulting excitation energies of the light and heavy fragments are consistent with the appearance of sawtooth structures.We found that the pairing correlation strengths have a significant influence on the partition of the excitation energies.Furthermore,the excitation energies of isotopic fragments increase with increasing neutron number,implying the suppression of the production of neutron-rich beams in rare-isotope beam facilities.
基金Supported by the Natural Science Foundation of Hebei Province,No.H2021206187 and No.H2021206452.
文摘BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an important mechanism of DCD.Blocking calcium overload and restoring calcium homeostasis are key steps in treatment.Transient receptor potential melastatin 7(TRPM7)is a novel player in causing calcium overload.Our previous studies have shown that genetic silencing of TRPM7 in type 1 diabetic rats leads to significant improvements in cognitive function,but the specific mechanism remains unclear.Troxerutin,extracted from the flowers of Sophora japonica,is one of the derivatives of rutin and has been shown to have neuroprotective effects.However,its association with TRPM7 remains unclear.AIM To use animal and cellular models,we investigated whether TRPM7 mediated mitochondrial fission by upregulation of calcineurin(CaN)/dynamin-related protein 1(Drp1)ser637 in DCD,and whether Troxerutin improved DCD by inhibiting TRPM7-mediated mitochondrial division.METHODS In this study,we used db/db mice and hippocampal neuronal cell lines(HT22)treated with high-concentration glucose as our study subjects.We evaluated cognitive function using Morris water maze,novel object recognition tasks,and Nesting tests.We observed mitochondrial morphology using transmission electron microscopy and measured mitochondrial energy metabolism indicators using a spectrophotometer.We also detected mRNA and protein expression of TRPM7,CaN,p-Drp1^(ser637),caspase-3,B-cell lymphoma 2 associated X protein,and B-cell lymphoma 2 using quantitative real-time polymerase chain reaction,western blotting,and immunofluorescence.RESULTS In the db/db diabetic mice with cognitive dysfunction,as well as in hippocampal neurons exposed to high-concentration glucose,TRPM7 and CaN expression were upregulated,phosphorylated Drp1^(ser637)expression was downregulated,and mitochondrial fission was increased.By modulating(inhibiting or overexpressing)TRPM7,it was further validated that TRPM7 activates the CaN/Drp1^(ser637)pathway,resulting in an increase in mitochondrial fission and neuronal cell apoptosis.Troxerutin downregulated TRPM7/CaN/Drp1^(ser637),reduced mitochondrial fission,and improved DCD.CONCLUSION TRPM7 promotes mitochondrial fission via the CaN/Drp1^(ser637)pathway.Troxerutin improves mitochondrial function and reduces neuronal damage by inhibiting this pathway,suggesting TRPM7 as a potential therapeutic target for DCD.
文摘Photofission fragments mass yield for^(232)Th,^(234;238) U,^(237) Np, and^(239;240;242) Pu isotopes are investigated.The calculations are done using a developed approach based on Gorodisskiy's phenomenological formalism. The Gorodisskiy's method is developed to be applied for the neutron-induced fission. Here we revised it for application to photofission. The effect of emitted neutron prior to fission on the fission fragment mass yields has also been studied. The peak-to-valley ratio is extracted for the240 Pu isotope as a function of energy. Obtained results of the present formalism are compared with the available experimental data. Satisfactory agreement is achieved between the results of present approach and the experimental data.
基金supported by the National Key R&D Program of China(No.2022YFA1602000)National Natural Science Foundation of China(Nos.12275081,U2067205,11790325,and U1732138)the Continuous-support Basic Scientific Research Project。
文摘Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pairing forces,as well as a combination of these two forces,were used for the Hartree–Fock–Bogoliubov approximation.Variations in the least-energy fission path,fission barrier,pairing energy,total kinetic energy,scission line,and mass distribution of the fission fragments based on the different forms of the pairing forces were analyzed and discussed.The fission dynamics were studied based on the timedependent generator coordinate method plus the Gaussian overlap approximation.The results demonstrated a sensitivity of the mass and charge distributions of the fission fragments on the form of the pairing force.Based on the investigation of the neutron-induced fission of^(239)Pu,among the volume,mixed,and surface pairing forces,the mixed pairing force presented a good reproduction of the experimental data.
文摘Photofission enables a unique capability for the domain of non-chemical space propulsion. An ultra-intense laser enables the capacity to induce nuclear fission through the development of bre- msstrahlung photons. A fundamental architecture and performance analysis of a photofission pulsed space propulsion system through the operation of an ultra-intense laser is presented. A historical perspective of previous conceptual nuclear fission propulsion systems is addressed. These applications use neutron derived nuclear fission;however, there is inherent complexity that has precluded further development. The background of photofission is detailed. The conceptual architecture of photofission pulsed space propulsion and fundamental performance parameters are established. The implications are the energy source and ultra-intense laser can be situated far remote from the propulsion system. Advances in supporting laser technologies are anticipated to increase the potential for photofission pulsed space propulsion. The fundamental performance analysis of the photofission pulsed space propulsion system indicates the architecture is feasible for further evaluation.
文摘The studies of thermal fission rates are relevant to novel reactors,astrophysical environments,and survival probabilities of compound superheavy nuclei.This has been conventionally studied by the Bohr-Wheeler statistical model that depends on phenomenological level densities and fission barriers.In this context,we propose to study the thermal fission rates based on microscopic temperature dependent nuclear energy density functional theory.The microscopic temperature dependent fission barrier heights and curvatures,and collective mass parameters can be self-consistently obtained.The fission lifetimes from low to high temperatures can be given by the imaginary free energy method in a consistent framework.Microscopic temperature dependent fission barriers play an essential role in fission studies.
文摘Project New Orion entails a pulsed nuclear space propulsion system that utilizes photofission through the implementation of an ultra-intense laser. The historical origins derive from the endeavors of Project Orion, which utilized thermonuclear devices to impart a considerable velocity increment on the respective spacecraft. The shear magnitude of Project Orion significantly detracts from the likelihood of progressive research development testing and evaluation. Project New Orion incorporates a more feasible pathway for the progressive research development testing and evaluation of the pulsed nuclear space propulsion system. Photofission through the application of an ultra-intense laser enables a much more controllable and scalable nuclear yield. The energy source for the ultra-intense laser is derived from a first stage liquid hydrogen and liquid oxygen chemical propulsion system. A portion of the thermal/kinetic energy of the rocket propulsive fluid is converted to electrical energy through a magneto-hydrodynamic generator with cryogenic propellant densification for facilitating the integral superconducting magnets. Fundamental analysis of Project New Orion demonstrates the capacity to impart a meaningful velocity increment through ultra-intense laser derived photofission on a small spacecraft.
