Nuclear Fusion Processes Research Articles

Deep Learning Models to Reduce Stray Light in TJ-II Thomson Scattering Diagnostic.

Nuclear fusion is a potential source of energy that could supply the growing needs of the world population for millions of years. Several experimental thermonuclear fusion devices try to understand and control the nuclear fusion process. A very interesting diagnostic called Thomson scattering (TS) is performed in the Spanish fusion device TJ-II. This diagnostic takes images to measure the temperature and density profiles of the plasma, which is heated to very high temperatures to produce fusion plasma. Each image captures spectra of laser light scattered by the plasma under different conditions. Unfortunately, some images are corrupted by noise called stray light that affects the measurement of the profiles. In this work, we propose the use of deep learning models to reduce the stray light that appears in the diagnostic. The proposed approach utilizes a Pix2Pix neural network, which is an image-to-image translation based on a generative adversarial network (GAN). This network learns to translateimages affected by stray light to images without stray light. This allows for the effective removal of the noise that affects the measurements of the TS diagnostic, avoiding the need for manual image processing adjustments. The proposed method shows a better performance, reducing the noise up to 98% inimages, which surpassesprevious works that obtained 85% for the validation dataset.

Nuclear Fusion in Yeast and Plant Reproduction.

Nuclear fusion is essential for the sexual reproduction of various organisms, including plants, animals, and fungi. During the life cycle of flowering plants, nuclear fusion occurs three times: once during female gametogenesis and twice during double fertilization, when two sperm cells fertilize the egg and the central cell. Haploid nuclei migrate in an actin filament-dependent manner to become in close contact and, then, two nuclei fuse. The nuclear fusion process in plant reproduction is achieved through sequential nuclear membrane fusion events. Recent molecular genetic analyses using Arabidopsis thaliana showed the conservation of nuclear membrane fusion machinery between plants and the budding yeast Saccharomyces cerevisiae. These include the heat-shock protein 70 in the endoplasmic reticulum and the conserved nuclear membrane proteins. Analyses of the A. thaliana mutants of these components show that the completion of the sperm nuclear fusion at fertilization is essential for proper embryo and endosperm development.

Possibility of processing tungsten dust waste from the nuclear fusion process by a combination of several technologies

The processing of tungsten dust waste from the nuclear fusion process is being considered for the EU DEMO within the Workpackage Safety and Environment in the EUROfusion programme.A multi-step procedure with a combination of several independent technologies is proposed. Specific technologies are gradually being proposed, however their combination has not been tested yet. Removal of tritium from tungsten dust by a Molten Salt Oxidation technology (MSO) is investigated while, simultaneously, tungsten is retained in the molten salt and tritium is trapped in the form of condensed tritium water. Tungsten salts are concentrated in several stages by a combination of chemical methods, settling, and centrifugation. The dissolution and concentration procedures alternate in a defined manner. The concentrate is gradually enriched with tungsten and tungsten salts. The molar volume of tungsten progressively increases in the concentrated salt suspension.Further removal of certain impurities, decomposition of salts, and the increase of the tungsten concentration in the product can be achieved by means of Induction Melting or Induction Heating in a Cold Crucible (IMCC or IHCC) in a suitable atmosphere. The final stage is the reprocessing of the concentrated tungsten product from the dust form into a compact piece of material. Induction Heating technology will enable its sintering, compaction, and reduction of porosity.

Kinetic model of resonant nanoantennas in polymer for laser induced fusion

Studies of resilience of light-resonant nanoantennas in vacuum are extended to consider the case of polymer embedding. This modifies the nanoantenna’s lifetime and resonant laser pulse energy absorption. The effective resonance wavelength is shortened, the peak momentum of resonantly oscillating electrons in the nanorod is reduced by one-third, while the available lifespan of the resonance condition remains the same. This response is expected to strengthen the laser pulse induced nuclear fusion processes. Related numerical simulations were performed using particle-in-cell method in a simulation box of the size 0.223 μm3, treating the conduction electrons as strongly coupled plasma. In the modeling the polymer background was added with the experimentally measured refractive index of 1.53.

Влияние состояния рабочей поверхности гальванического датчика импульсного рентгеновского излучения на его быстродействие

A new design of a galvanic sensor of pulsed X-ray radiation is proposed, which is a flat electric capacitor with a window in one metal lining and a solid dielectric made of the single crystal sapphire with a thickness of 200-300 µm inside. The influence of the surface roughness of the sapphire in the window area on the galvanic linear sensor of X-ray radiation has been established. Tests have shown that with ultra-smooth polishing of the sapphire plate working surface in the window area to a roughness of Rq≤ 0.2 nm, it is possible to provide the galvanic linear detection of X-rays with an energy in the range of 0.1-1 keV and a power density of 1-2 MW•cm-2 with a sensor response time of about 8 ns. Sensors of this type can be used in studies of inertial nuclear fusion processes

Influence of the working surface roughness of the pulsed X-ray radiation galvanic sensor on its performance

A new design of a galvanic sensor of pulsed X-ray radiation is proposed, which is a flat electric capacitor with a window in one metal lining and a solid dielectric made of a single-crystal sapphire with a thickness of 200-300 μm inside. The influence of the surface roughness of the sapphire in the window area on the galvanic linear sensor of X-ray radiation has been established. Tests have shown that, with ultra-smooth polishing of the sapphire plate working surface in the window area to a roughness of Rq≤ 0.2 nm, it is possible to provide the galvanic linear detection of X-rays with an energy in the range of 0.1-1 keV and power density of 1-2 MW· cm-2 with a sensor response time of about 8 ns. Sensors of this type can be used in studies of inertial nuclear fusion processes. Keywords: X-ray radiation, galvanic sensor, sapphire, dielectric, flat capacitor.

γ Columbae as a recently stripped pulsating core of a massive star

A vital condition for life on Earth is the steady supply of radiative heat by the Sun. Like all other stars, the Sun generates its emitted energy in its central regions where densities and temperatures are high enough for nuclear fusion processes to take place. Because stellar cores are usually covered by an opaque envelope, most of our knowledge about them and their life-giving nuclear processes comes from theoretical modelling or from indirect observations such as the detection of solar neutrinos and the study of stellar pulsations, respectively. Only in very rare cases, stars may expose their cores, e.g., when a tiny fraction of them evolves into Wolf-Rayet or helium hot subdwarf stars. However, for the vast majority of stars, namely unevolved stars that burn hydrogen to helium in their centres, direct observational clues on the cores are still missing. Based on a comprehensive spectroscopic and asteroseismic analysis, we show here that the bright B-type star $\gamma$ Columbae is the stripped pulsating core (with a mass of $4$-$5\,M_\odot$, where $M_\odot$ is the mass of the Sun) of a previously much more massive star of roughly $12\,M_\odot$ that just finished central hydrogen fusion. The star's inferred parameters indicate that it is still in a short-lived post-stripping structural readjustment phase, making it an extremely rare object. The discovery of this unique star paves the way to obtain invaluable insights into the physics of both single and binary stars with respect to nuclear astrophysics and common-envelope evolution. In particular, it provides first observational constraints on the structure and evolution of stripped envelope stars.

Future development of global molybdenum-99 production and saving of atmospheric radioxenon emissions by using nuclear fusion-based approaches

Technetium-99m, the decay product of molybdenum-99, is the most used medical isotope in diagnostic imaging. The future disruptions of molybdenum-99 supply, due to the final shut down of some old producing reactors, has led some current global supplies to plan the expansion of their production capacity. While other countries are developing own production facilities to supply their domestic demand. The global increase of molybdenum-99 production in the coming years could increase by about five times the current demand, with about the 50 percent of additional production in North America. Xenon radionuclides are an inevitable by-product of the nuclear plants production, and their periodically release into the atmosphere, contribute to the background that is also revealed by the IMS stations of the CBTO treaty. In this framework, the development of new technologies, posing no risk in relation to nuclear proliferation and do not result in emissions of radioxenon, could mitigate the issues related to the forecast increase of molybdenum-99 production worldwide. In Italy, an alternative 99Mo production project, the project ENEA Sorgentina, based on the irradiation of molybdenum by neutrons produced by a deuterium-tritium nuclear fusion process, is under development. This facility will not release radioxenon into the atmosphere, so it will not affect the background value in the atmosphere in Southern Europe.

Development of a solar radiation sensor system with pyranometer

<span>Solar energy is a result of the nuclear fusion process in the form of a series of thermonuclear events that occur in the Sun's core. Solar radiation has a significant impact on the lives of all living things on earth. The uses, as mentioned earlier, are when the solar radiation received requires a certain amount and vice versa. As a result, a more accurate instrument of solar radiation is required. A specific instrument is typically used to measure solar radiation parameters. There are four solar radiation parameters: diffusion radiation, global radiation, direct radiation, and solar radiation duration. Thus, it needs to use many devices to measure radiation data. The paper designs to measure all four-radiation data by pyranometer with particular modification and shading device. This design results have a high correlation with a global standard with a value of R=0.73, diffusion with a value of R=0.60 and a sufficiently strong direct correlation with a value of R=0.56. It can be said that the system is much simpler, making it easier to monitor and log the various solar radiation parameters.</span>

MXene‐Sponge Based High‐Performance Piezoresistive Sensor for Wearable Biomonitoring and Real‐Time Tactile Sensing (Small Methods 2/2022)

Flexible Piezoresistive Pressure Sensor In article number 2101051, Ye, Xie, Su, Chen and co-workers were inspired by Helium embrittlement during nuclear fusion processes, to utilize Helium plasma irradiation to yield a nano-fuzz-shaped molybdenum electrode for a flexible piezoresistive pressure sensor, which was demonstrated to measure human radial pulse, detect the tapping, stamping, and perform object identification, revealing great feasibility in wearable biomonitoring and healthcare assessment.

Magnetic confinement for the 2D axisymmetric relativistic Vlasov-Maxwell system in an annulus

<p style='text-indent:20px;'>Although the nuclear fusion process has received a great deal of attention in recent years, the amount of mathematical analysis that supports the stability of the system seems to be relatively insufficient. This paper deals with the mathematical analysis of the magnetic confinement of the plasma via kinetic equations. We prove the global wellposedness of the <i>Vlasov-Maxwell</i> system in a two-dimensional annulus when a huge (<i>but finite-in-time</i>) external magnetic potential is imposed near the boundary. We assume that the solution is axisymmetric. The authors hope that this work is a step towards a more generalized work on the three-dimensional Tokamak structure. The highlight of this work is the physical assumptions on the external magnetic potential well which remains finite <i>within a finite time interval</i> and from that, we prove that the plasma never touches the boundary. In addition, we provide a sufficient condition on the magnitude of the external magnetic potential to guarantee that the plasma is confined in an annulus of the desired thickness which is slightly larger than the initial support. Our method uses the cylindrical coordinate forms of the <i>Vlasov-Maxwell</i> system.</p>

Nuclear Fusion Research and Development Need New Relativistic Mass and Energy Corrections Given by the Information Relativity Theory

Hundred years after the conjecture of the British astronomer Eddington that the sun is powered by nuclear fusion of hydrogen, new physics theory may help make energy harvesting by nuclear fusion soon a reality. Researchers as well as investors funding fusion megaprojects are asked to deal with new relativistic corrections for mass and energy proposed by Suleiman in his Information Relativity Theory (IRT). These corrections were calculated in this contribution. It will help to decide whether a venture will be successful and to save big investments when in doubt. The assumed optimal kinetic energy for controlled nuclear fusion must be corrected to a somewhat higher level. At very high kinetic energy in the upper GeV range, it remains not enough baryonic mass to be transformed in energy. The fusion probability faded out to zero already at the golden limit of the recession speed of between target nucleon and projectile nucleon. Cold nuclear fusion, if ever possible, is recommended for protons rather than deuterons at highest experimental possible temperatures around 1000 (K) and needs fine-tuned kinetic nucleon energy. It would be also of interest whether a golden ratio based nuclear fuel confinement chamber could be beneficial. In this connection, also cold nuclear fusion setups should be discussed. Nature is governed by the golden ratio and criticality of physical systems influenced by it, and nuclear physics is not an exception. Computer simulations of the underlying controlled nuclear fusion processes should gain profit from IRT corrected starting information and may tackle anew possible low energy nuclear transmutations considering the wave-like dark components of matter and energy.

Fusion of spherical-octupole pairs of colliding nuclei for compact and elongated configurations * *The financial support from Council of Scientific & Industrial Research (CSIR), in the form of a Senior Research Fellowship, DAE, Government of India, sanction no. 58/14/12/2019-BRNS and UGC-DAE consortium for Scientific Research, File No. UGC-DAE-CSR-KC/CRS/19/NP09/0920 are gratefully acknowledged

The deformation and associated optimum/uniquely fixed orientations play an important role in the synthesis of compound nuclei via cold and hot fusion reactions, respectively, at the lowest and highest barrier energies. The choice of optimum orientation ( ) for the ‘cold or elongated’ and ‘hot or compact’ fusion configurations of quadrupole ( ) deformed nuclei depends only on the +/- signs of -deformation [J. Phys. G: Nucl. Part. Phys. 31, 631-644 (2005)]. In our recent study [Phys. Rev. C 101, 051601(R) 2020], we proposed a new set of (different from the values reported for quadrupole deformed nuclei) after the inclusion of octupole deformation (up to ) effects. Using the respective of -deformed nuclei for cold and hot optimum orientations, we analyzed the impact of the soft- and rigid-pear shapes of octupole deformed nuclei on the fusion barrier characteristics (barrier height and barrier position ). This analysis is applied to approximately 200 spherical-plus- deformed nuclear partners, that is, 16O, 48Ca+octupole deformed nuclei. Compared with the compact configuration, the elongated fusion configuration has a relatively larger impact on the fusion barrier and cross-sections owing to the inclusion of deformations up to . Its agreement with available experimental data for the 16O+150Sm reaction ( =0.205, =-0.055) also improves when the optimum orientation degree of freedom is fixed in view of octupole deformations. This reinforces the fact that nuclear structure effects play an important role in the nuclear fusion process. Thus, octupole deformed nuclei can be used for the synthesis of heavy and superheavy nuclei.

Laser-induced annihilation: Relativistic particles from ultra-dense hydrogen H(0)

Particle annihilation means that nuclear particles annihilate each other (for example nucleons like a neutron and an anti-neutron) and generate showers of mesons (mainly kaons and pions) at high energy. The kaons decay via pions and muons to electrons, positrons, neutrinos and photons. The energy which can be extracted from the very fast particles is of the order of 50% of the total energy of the nucleon masses involved or 500 MeV per mass unit. Several reports have been published recently on the meson showers ejected by pulsed-laser impact on ultra-dense hydrogen H(0). Since the particle velocities often are relativistic at >100 MeVu−1 it is clear that a much more efficient nuclear process is responsible than in a normal hydrogen isotope fusion process (which can give only 3 and 15 MeV per mass unit out). The first experiment showing heat production above break-even in a laser-induced nuclear process in H(0) was published in AIP Avances as early as 2015. Here, we use a standard method for relativistic particle detection to show that the particles ejected by the laser pulse from D(0) are charged (thus not photons), and in fact positive, and that the signals decay with the characteristic decay times of kaons and pions with uncertainty < 1%. Using the measured kinetic energies of the mesons gives exact energy conservation. We conclude that annihilation of nucleons in H(0) is observed. This may have profound effects on future energy production, since the efficiency of the fuel in annihilation is roughly a factor of 100 higher than in a nuclear fusion process. Ordinary hydrogen (protium and deuterium) can be used as fuel instead of radioactive tritium. This means that energy is generated at low cost and with very little harmful radiation both for terrestrial and space applications (Acta Astronautica 2020).

Progress in preparing real-time control schemes for Deuterium-Tritium operation in JET

Operation of a magnetic fusion experiment, such as JET, relies on the availability of real-time (RT) control schemes, which supervise the plasma as it approaches the expected target performance while maintaining the integrity of the machine and its subsystems. At JET, there have been a series of recent efforts since (Lennholm M. et al 2017 Fusion Engineering and Design 123 535–540) to develop and test RT control schemes in preparation for the upcoming Deuterium-Tritium (DT) campaign. When operating JET in DT, each plasma discharge will in fact be a precious resource, being both T and neutron budget limited. Among the developed control schemes, this paper deals with the isotope ratio controller, which will maintain the required 50:50 DT ratio needed to favor nuclear fusion processes; the dud detector (L. Piron et al 2019 Fusion Engineering and Design 146 1364–1368), which will terminate a discharge moving toward controllers for detecting excessive radiation. Moreover, brand-new detectors, also based on machine learning approaches, have been implemented for detecting off-normal events or pre-disruptive states and have been included in the Plasma Event TRiggering and Alarms system (C.I. Stuart et al 2020 SOFT conference). Work is also ongoing to deploy into JET the RAPTOR suite, a RT observer for plasma state monitoring (C. Piron et al 2020 SOFT conference), and to identify control schemes within RAPTOR capabilities, which could contribute to support the development of high performance plasma scenarios.

Formula omitted] Breakup and formation at astrophysical energies

The main components of nuclear fusion processes that occur in stars are the radiative capture and its inverse reaction, during helium transforms into heavier elements. The deuteron-alpha radiative capture and the 6Li(γ,α)d reactions are studied using Effective Field Theory (EFT). The scattering amplitude for the initial P-wave states of deuteron-alpha for the sum of E1 and E2 transition are found, up to next to leading order (NLO). Furthermore, the photodisintegration rate of the 6Li(γ,α)d reaction is calculated. The obtained results are in good agreement with the available experimental data and those of other theoretical models, at astrophysical energies.

A transient process observation method based on the non-homogeneous Poisson process model * *Support of the National Natural Science Foundation of China (1435010, 11575145, 11922507)

The current-mode-counting method is a new approach to observing transient processes, especially in transient nuclear fusion, based on the non-homogeneous Poisson process (NHPP) model. In this paper, a new measurement process model of the pulsed radiation field produced by transient nuclear fusion is built based on the NHPP. A simulated measurement is performed using the model, and the current signal from the detector is obtained by simulation based on Poisson process thinning. The neutron time spectrum is reconstructed and is in good agreement with the theoretical value, with its maximum error of a characteristic parameter less than 2.3%. Verification experiments were carried out on a CPNG-6 device at the China Institute of Atomic Energy, with a detection system with a nanosecond response time. The experimental charge amplitude spectra are in good agreement with those obtained by the traditional counting mode, and the characteristic parameters of the time spectrum are in good agreement with the theoretical values. This shows that the current-mode-counting method is effective for the observation of transient nuclear fusion processes.

A bidimensional quasi-adiabatic model for muon-catalyzed fusion in muonic hydrogen molecules

A two-dimensional model for muonic molecules with nuclei composed of proton-proton, deuterium-deuterium, and tritium-tritium is proposed and solved. The effective molecular potential is analytically calculated within a quasi-adiabatic approximation. The molecular wave-functions and energies involved in the elementary process of muon-catalyzed nuclear fusion described by a Schrodinger equation were numerically calculated. Predictions are compared with three-dimensional results, showing that the dimensionality of space and the choice of potential energy have a great influence on some parameters used to calculate the probability of nuclear fusion. In particular, a 109 times greater probability was found for the ttμ molecule compared to the prediction in three-dimensions. Finally, we conclude that, from the theoretical point of view, these results highlight the distinguished role of the ``centrifugal potential’’ in the 2D effective potential, showing that the geometrical nature of planar space plays a quite relevant role in s-state muonic molecules in two spatial dimensions.

Enhancing the selectivity of hydrogen isotopic water in membrane distillation by using graphene oxide

Isotopes of hydrogen are playing an increasingly important role in applications such as controllable nuclear fusion and other nuclear processes, yet directly separating isotopic water from its mixture is still energy-intensive and largely limited by the moderate separation factor values. In this study, Graphene oxide (GO) and reduced graphene oxide (rGO) nanosheets, combining optimized hydrophobicity by grafting perfluoroalkylsilanes (PFAS), have been used for improving the selectivity of isotopic water in membrane distillation. By utilizing heavy/light water mixture as a model, permeation flux and isotopic selectivity of the membranes are systematically evaluated. The graphene oxide membranes, particularly for the rGO grafted by PFAS, exhibit enhanced selectivity with an increased isotopic separation factor, as compared with that of commercial membranes, which is probably due to the efficient synergy between unimpeded nanochannels and near-super hydrophobic surface. A maximum mean separation factor value of 1.067, combined with a permeation flux of 0.47 kg m−2 h−1 have been achieved for the grafted rGO -membrane reduced at 750 °C. Furthermore, our study demonstrates utilizing two-dimensional materials, like GO and rGO, can be an effective avenue for promoting the isotopic selectivity in membrane distillation, based on increasing hydrophobic water vapor channels with higher selectivity.

Formula omitted] Radiative capture process by effective field theory

Two of the main components of nuclear fusion processes which occur in stars are the radiative capture of deuteron-alpha and its inverse reaction during which helium transforms into larger elements. One of the reactions occuring is the production of 6Li through the d(α, γ)6Li reaction that is supported by the Big Bang model. The process of radiation in the energy region 0.07 MeV ≤ Ecm ≤ 0.41 MeV has been studied in the framework of Effective Field Theory (EFT) at low energy. Further, within the EFT framework deuteron is assumed as a dibaryon and the coulomb effect between deuteron and alpha is ignored. The reaction amplitude for the P-wave initial states 3P2, 3P0 and 2P3/2 and the astrophysical S-factor for sum of E1 and E2 transitions are found in the framework of EFT up to NLO. The results of this model for the astrophysical S-factor at low energies are comparable with the available experimental data and those of other theoretical models.