Studies on the Dynamics of D–T Fusion Reaction Based on the Relativistic Equilibrium Velocity Distribution

The Coulomb barrier is in general much higher than thermal energy. Nuclear fusion reactions occur only among few protons and nuclei (i.e., deuterium and tritium) with higher relative energies than Coulomb barrier. It is the equilibrium velocity distribution of these high-energy protons and nuclei that participates in determining the rate of nuclear fusion reactions. In the circumstance it is inappropriate to use the Maxwellian velocity distribution for calculating the nuclear fusion reaction rate. We use the relativistic equilibrium has a reduction factor with respect to that based on the Maxwellian distribution, which factor depends on the temperature, reduced mass and atomic numbers of the studied nuclear fusion reactions. In this paper, we concluded at energy range 10⁵ (keV) ≤ E ≤ 10⁶ (keV), that is smaller than reduced mass energy of deuterium–tritium, m _r c ², the numerical values of R and R _M are not different from each other very much, but by increasing energy near the region of m _r c ² the difference between them are visible, also by increasing energy for example 9 × 10⁶ (keV) ≤ E ≤ 10 × 10⁶ (keV) the difference is obviously more visible. Therefore, we have to use relativistic equilibrium velocity distribution instead of Maxwellian velocity distribution.     

In search of nuclear fusion in electrolytic cells and in metal/gas systems

It has been reported recently in the literature that unexpected thermal and nuclear effects (production of excess heat, neutrons, γ-rays, and tritium) can occur during the electrolysis of heavy water at palladium or titanium electrodes, or during temperature and pressure cycling of the titanium/deuterium gas system. We have attempted to reproduce some of these experiments. A variety of electrochemical cells having palladium cathodes in the form of wires, tubes, sheets, and rods have been used to electrolyze heavy water containing 0.1 mol.dm⁻³ LiOH, 0.1 mol.dn⁻³ LiOD or 0.5 mol.dm⁻³ D₃PO₄. Current densities of up to 200 mA.cm⁻² were applied. The mass of the palladium cathodes covered the range from 1–40 grams and the surface area varied from 8–140 cm². Neutron detection systems with low constant backgrounds were used to search for neutron emission during electrolysis. These included³He- and¹⁰BF₃-based detectors. After running some of the cells for more than 30 days, no neutron emission above background could be detected. This puts upper limits of 0.5 s⁻¹ and 2×10⁻²³ fus. D-D.s⁻¹ on the neutron emission and the fusion rate, respectively. A sensitive and accurate heat-flow calorimeter was built and used to monitor the energy balance of some of the cells during electrolysis. No unexpected heat effects were observed. This puts an upper limit of 0.13 W.cm⁻³ on the specific excess power. No enrichment of the electrolyte in tritium was evident after electrolysis. Experiments were also performed with the titanium/ deuterium gas system. These consisted of exposing titanium metal to a deuterium gas pressure of 40 atmospheres, lowering the temperature to −196°C, releasing the pressure and gradually warming the titanium to room temperature. No neutron emission above background was observed during these experiments, which puts upper limits of 0.5 s⁻¹ and 4×10⁻²⁵ fus.D-D.s⁻¹ on the neutron emission and fusion rate, respectively. Submitted toJournal of Fusion Energy as part of the Proceedings of the Workshop on Cold Fusion Phenomena held in Santa Fe in May 1989.     

Tritium Released from Mantle Source: Implications for Natural Nuclear Fusion in the Earth’s Interior

This paper summarizes the observation results of mantle tritium (³H) in two volcanic lakes, Lakes Nemrut (Turkey) and Laacher (Germany). The presence of excess ³H in the lakes can be explained as material released from mantle source because of the correlation of excess ³H with mantle ³He and ⁴He. We conclude that excess ³H in these two lakes, after the origin of the excess ³H from atmosphere and conventional nuclear reactions are excluded and the correlation of the excess ³H and mantle ³He is considered, might be from a mantle source and produced by nuclear fusion (d–d reaction) in the deep Earth. We have also investigated helium isotopes in the hydrothermal vent fluids at Mid-Ocean Ridge (MOR). The results show nearly constant ³He/⁴He ratio (³He/⁴He = 1.12 ± 0.13 × 10⁻⁵) and approximately constant ³He/heat ratios ((5–10) × 10⁻¹⁸ mol/J). The correlation of ³He with ⁴He and heat suggests that it is reasonable to suppose ³He is produced by nuclear fusion (d–d reaction) and ⁴He from α-decay of U and Th in the deep Earth. Based on that, ³He/⁴He ratios for 10 hydrothermal vent fluids are calculated. The results agree with the measurement at hydrothermal vent fluids and Mid-Ocean Ridge Basalts (MORB) on the average. We concludes that the narrow distribution of ³He/⁴He ratio peaked at ∼8 R_A in MORB can be explained by the hypothesis that ³He is produced in nuclear fusion.     

Kinetics of the leaching of90Sr from fuel particles in soil in the near zone of the chernobyl nuclear power plant

A method is presented for calculating the fraction of⁹⁰Sr included in fuel particles in soil. Data concerning the change in forms of the occurrence of⁹⁰Sr in different soils in the 30-km zone, at different distances from the Chernobyl nuclear power plant, were used to obtain the kinetic characteristics of its leaching: the first-order rate constant and the normalized rate of solution. Depending on the direction and distance from the nuclear power plant, the first-order leaching rate constant varies from 3·10⁻⁵ to 2·10⁻³ days⁻¹ and the normalized rate of solution of the fuel matrix varies from 1·10⁻⁵ to 6.1·10⁻⁴. It was not found possible to clearly identify the influence of the distance from the nuclear power plant on the leaching rate in the northern and western sectors. In contrast, in the southerly and south-easterly directions a clear tendency was observed for the leaching rate to increase with increasing distance from the nuclear power plant. Taifun Scientific Production Enterprise. Translated from Atomnaya énergiya, Vol. 86, No. 2, pp. 129–134, February, 1999.     

Experimental Study of the Iranian Inertial Electrostatic Confinement Fusion Device as a Continuous Neutron Generator

Among many facilities in the field of nuclear fusion devices, inertial electrostatic confinement (IECF) device has the specific character of tendency to generate fusion products continuously. Besides the distinctive characteristics, it has become an outstanding focus of interest for many scientists because of several applications such as the ability of performing hydrogen boron fusion. This paper summarizes primary results of the design and construction of the first Iranian IECF device (IR-IECF). It consists of 13.5 cm diameter stainless steel cathode, 41 cm diameter anode with a 60 cm diameter and 60 cm height vacuum chamber. The outcomes of neutron detection represent more than 10⁷ neutron/s at the maximum biased voltage of −140 kV and 70 mA current with deuterium operational filling gas in the steady state regime.     

Condensed Atomic Hydrogen as a Possible Target in Inertial Confinement Fusion (ICF)

H atom Rydberg matter (RM) in excitation state n = 1 is concluded to be a form of metallic hydrogen [Badiei S, Holmlid L (2004) J Phys Condens Matter 16:7017]. This material can be produced at low pressure. This condensed form of hydrogen may be very useful as a dense hydrogen inertial confinement fusion (ICF) target, being almost metallic and ten times denser than solid (frozen) diatomic hydrogen used at present. Coulomb explosions and plasma formation are initiated in condensed atomic hydrogen even by relatively weak nanosecond pulsed lasers. The protons emitted with high directivity in these explosions are energetic, corresponding to T = 10⁵ K, and they may be utilized to give strong compression of the material. The fastest protons observed at up to 1 keV indicate a compression considerably higher than that required for “fast ignition” fusion.     

Yield from Proton-Induced Reaction on Light Element Isotopes in the Hydrogen Plasma Focus

The high Q-value of some (p,α) fusion reactions is very important in the investigation that can lead to power production with controlled fusion using advanced fuels (hydrogen-lithium-7, hydrogen-boron-11). For this reason, it is crucial to know the rates of these fusion reactions. Unfortunately, in the fusion machines such as plasma focus device, the interaction energy is usually far below the Coulomb barrier. Because of that, direct measurements of the relevant reaction cross sections are practically impossible. A few different indirect approaches have been proposed. In this work the Trojan Horse Method (THM) will be described. On the basis of the results obtained from the THM method and data, which are well-known from our previous work (Banjanac et al. in Radiat Meas 40:483–485, 2005), the reaction rate for proton-induced reaction ⁷Li(p,α)α produced in the hydrogen plasma focus is calculated. This calculation will be compared with the measurements of α particles production rate using CR-39 detectors.     

Analysis of the characteristics of <Superscript>238</Superscript>U, <Superscript>232</Superscript>Th, <Superscript>237</Superscript>Np,and <Superscript>231</Superscript>Pa radiators for fission ionization chambers for measuring the neutron flux density in the ITER diverter

Computational results, obtained by analyzing possible schemes of nuclear transformations of each of four threshold fission radiators ²³⁸U, ²³²Th, ²³⁷Np, and ²³¹Pa, for fission ionization chambers are presented. The influence of the nuclear reactions (n, ƒ), (n, γ), and (n, 2n) on the characteristics of fission ionization chambers is taken into account in the nuclear transformation schemes for all four radiators. The results are presented in the form of a dependence of the sensitivity of the fission ionization chambers on the neutron fluence in the range 10²¹–10²⁴ cm⁻². The effect of 0.2 and 1 g/cm² thick boron screens is examined. Translated from Atomnaya énergiya, Vol. 106, No. 1, pp. 42–47, January, 2009.     

Inclusion of Radioactive Ion-Exchange Resins in Inorganic Binders

This article is devoted to the inclusion of ion exchange resins in portland, portland blast-furnace, and alumina cements. The degree to which the solidified products are filled with respect to dry resin reaches 7–10, 12, and 18.9–19.7%, respectively, with adequate strength being maintained (at least 5 MPa); the cesium diffusion coefficients are 9.3·10⁻⁴, 1.2·10⁻⁴, and 7.2·10⁻⁵ cm²/day with the normative value 6.7·10⁻⁴ cm²/day. When 10 mass% clay is added to alumina cement, the diffusion coefficient of cesium decreases to 5.1·10⁻⁶ cm²/day, and the volume of the wastes increases by not more than a factor of 1.5 on solidification. __________ Translated from Atomnaya Energiya, Vol. 99, No. 3, pp. 171–177, September, 2005.     

<Superscript>59</Superscript>Ni Accumulation in Corrosion-Resistant Steel under the Action of Neutron Flux

A γ-ray line with energy E_γ = 11.3 MeV was detected during an experiment, performed on a nuclear reactor, investigating the characteristics of the energy spectrum of γ-rays. The most likely source of this line is radiative capture of thermal neutrons by ⁵⁹Ni nuclei, which accumulated in the corrosion-resistance steel as a result of the more than 20 years of irradiation in the reactor, via the reaction ⁵⁸Ni(n, γ)⁵⁹Ni. It was found that for thermal-neutron fluence 10²¹ cm⁻² the ⁵⁹Ni concentration is 0.47% of the ⁵⁸Ni concentration. __________ Translated from Atomnaya Energiya, Vol. 99, No. 4, pp. 268–272, October, 2005.     

Direct measurements of the<Superscript>90</Superscript>Sr activity in water using Cherenkov radiation

A computational-experimental investigation of Cherenkov radiation due to⁹⁰Sr−⁹⁰Y in water samples was performed. The Monte Carlo method was used to simulate the generation of photons from the decay of⁹⁰Sr−⁹⁰Y and other isotopes in water in the range 220–600 nm. The Cherenkov radiation was measured using a low-noise photomultiplier with a tellurium-rubidium photocathode on a MgF₂ entrance window. Experiments on measuring the amplitude distributions and counting rates due to Cherenkov radiation from the radioactive solutions of⁹⁰Sr−⁹⁰Y,¹³⁷Cs−¹³⁷Ba, and⁴⁰K were performed. The sensitivity and lowest measurable activity for water samples of⁹⁰Sr−⁹⁰Y was estimated on the basis of the results obtained, 4 figures, 3 tables, 11 references. Russian Science Center “Kurchatov Institute.” Translated from Atomnaya énergiya, Vol. 88, No. 4, pp. 282–286, April, 2000.     

Preliminary study of high neutron flux fusion heating

A heating scheme for nuclear fusion is proposed based on the availability of a high flux, low energy neutron source. The heat is derived in the reaction ⁶Li (n, T) ⁴He resulting from the incidence of a low energy neutron beam on a sample of ⁶Li D. The energy release per reaction, Q = 4.6 MeV, is converted through electron Coulomb collisions thereby quickly dissociating the solid sample to the plasma state. For 10⁻³ eV neutrons it is estimated that this dissociation occurs in 7 ms for an incident flux of 10¹⁷ cm⁻² · s⁻¹. The possibility of further driving the heated fuel to fusion is also discussed.     

Ignition of a Deuterium Micro-Detonation with a Gigavolt Super Marx Generator

The Centurion–Halite experiment demonstrated the feasibility of igniting a deuterium–tritium micro-explosion with an energy of not more than a few megajoule, and the Mike test, the feasibility of a pure deuterium explosion with an energy of more than 10⁶ MJ. In both cases the ignition energy was supplied by a fission bomb explosive. While an energy of a few megajoule, to be released in the time required of less than 10⁻⁹ s, can be supplied by lasers and intense particle beams, this is not enough to ignite a pure deuterium explosion. Because the deuterium–tritium reaction depends on the availability of lithium, the non-fission ignition of a pure deuterium fusion reaction would be highly desirable. It is shown that this goal can conceivably be reached with a “Super Marx Generator”, where a large number of “ordinary” Marx generators charge (magnetically insulated) fast high voltage capacitors of a second stage Marx generator, called a “Super Marx Generator”, ultimately reaching gigavolt potentials with an energy output in excess of 100 MJ. An intense 10⁷ Ampere-GeV proton beam drawn from a “Super Marx Generator” can ignite a deuterium thermonuclear detonation wave in a compressed deuterium cylinder, where the strong magnetic field of the proton beam entraps the charged fusion reaction products inside the cylinder. In solving the stand-off problem, the stiffness of a GeV proton beam permits to place the deuterium target at a comparatively large distance from the wall of a cavity confining the deuterium micro-explosion.

Calculation of ρR-parameter and Energy Gain for Aneutronic Fusion in Degenerate P–11 B Plasma

Aneutronic fusion reactions are more safe and clean than the other reactions. One of the important candidate for these reactions is P–¹¹ B. This reaction in characteristic conditions creates degenerate plasma. In a Fermi-degenerate plasma, the electronic stopping of a slow ion is smaller than given by the classical formula, because some transitions between the electron states are forbidden. The bremsstrahlung losses are then smaller, so that the nuclear burning of an aneutronic fuel is more efficient. Practical obstacles in this regime that must be overcome before net energy can be realized include the compression of the fuel to an ultra dense state and the creation of a hot spot. In this paper, ρR parameter (Lawson’s criterion) and energy gain for P–¹¹ B are given.     

Studies on p+6Li Fusion Reaction using 3-Parameter Model

The 3-parameter model introduces 3 parameters (radius of a square nuclear potential well, the real part and the imaginary part of the nuclear potential depth) to describe the low energy behavior of the fusion cross-section for light nuclei. It has been justified by the experimental data from the National Nuclear Data Center (NNDC) for 3 major fusion reactions (d?+?T, d?+?D, and d?+?³He). In the present paper this 3-parameter model has been extended to p+⁶Li fusion reaction. It agrees with the fusion cross-section data from NNDC again. Moreover it is able to calculate the astrophysical S-factor with an electron screening potential for p+⁶Li fusion reaction as well. As a development of the 3-parameter model, the necessary condition for a low energy resonant tunneling through Coulomb barrier is derived. It reveals further the possibility of resonant tunneling at very low energy for p+⁶Li system.     

Reconstruction of metal embrittlement in a reactor vessel of the atomic icebreaker Lenin

Data from a study of radiation damage to the vessel of a reactor from the retired atomic icebreaker Lenin are used to determine the radiation embrittlement characteristics of the metal. Irradiation by a low neutron flux of 10¹⁰–10¹¹ cm⁻²sec⁻¹ at the beginning of operation is found to correspond to more intense embrittlement of the metal. Then, apparently, as harmful elements are depleted in the matrix of the metal, embrittlement is reduced until there is a change in sign relative to the standard curve obtained for neutron fluxes above 10¹³ cm⁻²sec⁻¹. It is proposed that, because of irradiation by low fluxes of neutrons in the peripheral zones of reactor vessels during some stages of operation, these zones may be damaged to a greater extent than those lying closer to the core. The irradiating neutron flux is a factor that influences the embrittlement of reactor vessel materials, so there is some interest in studying how material is damaged in the vessels of power reactors with low radiation loads which are under development. This is also needed in order to evaluate the efficacy of measures undertaken to reduce the effect of neutron irradiation on reactor vessels. Translated from Atomnaya énergiya, Vol. 105, No. 4, pp. 201–205, October, 2008.     

Investigation of radioactive contamination of graphite samples from the AM reactor

The world’s first nuclear power plant operated for almost 48 years. Over this period of time, the neutron fluence on the graphite masonry reached ∼10²² cm⁻², which resulted in activation of the impurities present in the graphite. During operation, incidents occurred with loss of seal and sometimes loss of integrity of the fuel-element claddings in some cells and particles of the fuel and steam-water mixture entered the graphite masonry. This resulted in radiation contamination with a complex radionuclide composition. Experimental information about the content and distribution of radionuclides in the spent nuclear graphite is needed in order to plan methods and periods of time for disassembly and salvaging of the graphite masonry of the stopped reactor taking account of the dose loads on the workers and the ecological safety norms. The problems which can be solved on the basis of the present work included the determination of the ¹⁴C and ³H contents by liquid-scintillation β spectrometry, analysis of the actinide content by direct γ spectrometry, and neutron-activation analysis followed by γ spectrometry. These investigation yielded new data on the content of fission products and activation impurities in graphite. __________ Translated from Atomnaya énergiya, Vol. 101, No. 5, pp. 358–364, November, 2006.     

Dynamical screening of potential by mobile deuteron and fusion rate of accelerated deuteron in PdDx

The Coulomb potential between deuterons in the PdDx deutende is dynamically screened by the mobile deuterons as well as the electrons. The screening effect by the mobile deuteron at low temperatures is substantial. When the all deuterons become mobile, the fusion rate observed by Jones et al. can be achieved using the classical formula for the ion polarization function, however, the rate using the quantum mechanical formula becomes 10^–6–10^–7 times smaller than the classical one. By the small increase in deuteron energy, of the order of a few electron volts, the fusion rate in PdDx deuteride increases substantially. But after about 10 eV of deuteron energy, the fusion rate does not increase at such a high rate as it does in the low-energy region. The fusion rate observed by Jones et al. might be explained by the acceleration of the deuteron by the electric field created in the domain boundary between the region containing the deuteron and the region without the deuteron or by the avalanche-type propagation of the fracture.     

An Investigation for Ground State Features of Some Structural Fusion Materials

Environmental concerns associated with fossil fuels are creating increased interest in alternative non-fossil energy sources. Nuclear fusion can be one of the most attractive sources of energy from the viewpoint of safety and minimal environmental impact. When considered in all energy systems, the requirements for performance of structural materials in a fusion reactor first wall, blanket or diverter, are arguably more demanding or difficult than for other energy system. The development of fusion materials for the safety of fusion power systems and understanding nuclear properties is important. In this paper, ground state properties for some structural fusion materials as ²⁷Al, ⁵¹V, ⁵²Cr, ⁵⁵Mn, and ⁵⁶Fe are investigated using Skyrme–Hartree–Fock method. The obtained results have been discussed and compared with the available experimental data.     

Radiation Conditions in Obninsk

Monitoring data are used as a basis to examine the radiation conditions in Obninsk, including an analysis of the radioactive emissions from the Physics and Power-Engineering Institute and the Scientific-Research and Physicochemical Institute, the content of technogenic radionuclides in atmospheric air, soil, surface waters, and the components of agricultural natural ecosystems, and an estimate of the dose and radiation risk to the public. The monitoring results show relatively low levels of technogenic radionuclides in the environment, much lower than the admissable values. It is recommended that regular radiation monitoring of the content of tritium in surface and underground waters and also iodine isotopes in air near the ground at Obninsk be continued. The total estimated dose, taking account of numerous pathways of technogenic irradiation of the public in Obninsk, is on the average about 10⁻⁵ Sv/yr, which corresponds to a negligibly low radiation risk, less than 10⁻⁶ under standard operating conditions of nuclear objects. __________ Translated from Atomnaya Energiya, Vol. 99, No. 3, pp. 214–221, September, 2005.