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The article presents results of comparative tests for the determination of deuterium fluxes permeating through walls of austenitic stainless steel AISI304 (DIN 1.4301) chamber and Al{sub 2}O{sub 3} based ceramic F99.7 chamber. Both chambers represent a piece of φ(ext)=26*φ(int)=22*117 mm{sup 3} tube with spherical bottom ending. It is shown that at 773 K and deuterium pressure of 1200 mbar the permeated deuterium flux through the stainless steel chamber constituted 8*10{sup -5} cm{sup 3}/s, while the flux through ceramic one it did not exceed the sensitivity of the measurement method threshold, namely about 1.5*10{sup -7} cm{sup 3}/s. The ceramic chamber turned out to survive more than 10{sup 3} cycles of heating up to 773 K with no damages. It did not lose its tightness up to 10 bar of internal deuterium pressure. The authors also present test results of a prototype bed for reversible tritium storage. The bed's case was made of alumina based ceramic F99.7, titanium being used as tritide making metal and high frequency induction used for heating the tritide metal. (authors)

The long-term contact of structural materials (SM) with tritium-containing media makes their properties in terms of kinetic permeability of hydrogen isotopes change. This change is the consequence of the defect formation in SM due to the result of {sup 3}He build-up generated by the radioactive decay of tritium dissolved in SM. This paper presents the experimental results concerning the permeability of hydrogen isotopes through CrNi35WTiAl alloy containing {sup 3}He and the impact of the presence of {sup 3}He and H on its mechanical properties. Tensile tests of cylindrical samples containing various concentrations of {sup 3}He (90, 230 and 560 appm) have been performed in inert and hydrogen atmospheres. The build-up of {sup 3}He has been made using the 'helium trick' technique. The maximal decrease in the plastic characteristics of the CrNi35WTiAl alloy occurs in samples with the highest {sup 3}He (560 appm) content at 873 K. The permeability of deuterium through the CrNi35WTiAl alloy in the initial state and that with 560 appm of {sup 3}He content was explored. The presence of this {sup 3}He concentration has shown an increase in deuterium permeability, evidently due to structural changes in the material under the impact of radiogenic helium.

A search for the muon-catalyzed fusion reaction d + d → 4He + γ in the ddμ muonic molecule was performed using the experimental installation TRITON with BGO detectors for γ-quanta. A high-pressure target filled with deuterium was exposed to the negative muon beam of the JINR Phasotron to detect γ-quanta with the energy 23.8 MeV. An experimental estimation for the yield of radiative deuteron capture from the ddμ state J = 1 was obtained at the level of ηγ ≤ 8 × 10−7 per fusion.

The quasi-isentropic compressibilities of deuterium and helium plasmas are measured in the pressure range 1500–5000 GPa at densities up to 8 g/cm3 using spherical experimental devices and an X-ray complex consisting of three betatrons and a multichannel optoelectronic system for taking X-ray images. The experimental results demonstrate the possibilities of high-energy-density experimental physics to reproduce the extreme states of substance typical of the Universe under laboratory conditions using the energy of traditional condensed explosives.

The paper presents designs of a set of high-pressure targets developed by RFNC-VNIIEF and JINR collaboration to study muon-catalyzed fusion at high density of hydrogen isotopes in a wide temperature range. Designs, technical and operating characteristics of the targets and service results are described.In 1997-2002 these targets were used to measure basic characteristics of muon catalysis in pure deuterium, binary D/T mixture and triple H/D/T mixture as a function of density ([variant phi] = 0.2 - 1.2 LHD{sup *}), temperature (T = 20-800 K) and concentration of hydrogen isotopes in a mixture.

Raman spectroscopy is a relevant method for obtaining objective data on isotopic exchange rate in a gaseous mix of hydrogen isotopes, since it allows one to determine a gaseous mix composition in real time without sampling. We have developed a high-pressure fiber-optic probe to be used for obtaining protium Raman spectra under pressures up to 400 MPa and we have recorded spectral line broadening induced by molecule collisions starting from ∼ 40 MPa. Using this fiber-optic probe we have performed experiments to study isotopic exchange kinetics in a gaseous mix of hydrogen isotopes (protium-deuterium) at pressures up to 200 MPa. Preliminary results show that the dependence of the average isotopic exchange rate related to pressure take unexpected values at the very beginning of the time evolution. More work is required to understand this inconsistency.

Muon catalyzed fusion (MCF) in deuterium was studied by the MCF collaboration on the Joint Institute for Nuclear Research Phasotron. The measurements were carried out with a high-pressure deuterium target in the temperature range 85–790 K at densities of about 0.5 and 0.8 of the liquid hydrogen density. The first experimental results for the ddμ molecule formation rate λddμ in the temperature range 400–790 K with a deuterium density of about 0.5 of the liquid hydrogen density are presented.

A search for the muon-catalyzed fusion (MCF) reaction d+d → 4He+γ in the ddμ muonic molecule was performed using the experimental MCF installation TRITON and NaI(Tl) detectors for γ quanta. A high-pressure target filled with deuterium was exposed to the negative muon beam of the JINR phasotron to detect γ quanta with an energy of 23.8 MeV. The first experimental estimation for the yield of radiative deuteron capture from the ddμ state J=1 was obtained at a level of ηγ≤2×10−5 per one fusion.

A design of the deuterium high-pressure target is presented. The target of a 76-cm3 volume is intended to study muon-catalyzed fusion reactions in ultrapure D2 (the concentration of impurities with Z > 1 is under 0.2 ppm) at temperatures of 80–800 K and up to 150-MPa pressures. The operation of the main target systems is described: the generation and purification of deuterium gas, refrigeration, heating, evacuation, control, and automated data acquisition. The target was used to determine the parameters of the muon-catalyzed fusion reactions in ultrapure D2 at temperatures of 300 to 800 K and pressures up to 150 MPa.

The design of deuterium high-pressure target of 76 cm3 volume developed to study muon catalyzed fusion in diffusion-pure deuterium over an 80–800 K temperature range at up to 150 MPa pressure is presented.

Muon catalyzed fusion in deuterium was studied by the MCF collaboration at JINR phasotron. The measurements were carried out with a high-pressure deuterium target at the JINR phasotron in the temperature range 300–800 K at densities ≃0.5 LHD. The first experimental results for ddμ-molecule formation rate λ ddμ in the temperature range 400–800 K with deuterium density 0.5 LHD are presented.

The quasi-isentropic compressibility of helium and deuterium plasmas at pressures of up to 1500–2000 GPa has been measured using devices with spherical geometry and an X-ray diagnostic complex comprising three betatrons and a multichannel imaging system with electro-optic gamma detectors. A deuterium density of 4.5 g/cm3 and a helium density of 3.8 g/cm3 have been obtained at pressures of 2210 and 1580 GPa, respectively. The internal energy of a deuterium plasma at the indicated pressure is about 1 MJ/cm3, which is about 100 times greater than the specific energy of condensed chemical explosives. Analysis of the obtained data shows that the degree of helium ionization under the achieved plasma compression parameters is about 0.9.

The technical approach, equipment and software developed during the creation of measurement and control systems for two complexes are described. The first one is a complex that prepares the gas mixture and targets of the 'TRITON' facility. The 'TRITON' facility is designed for studying muon catalyzed fusion reactions in triple mixtures of H/D/T hydrogen isotopes over wide ranges of temperature and pressure. The second one is 'ACCULINNA' - the liquid tritium target designed to investigate the neutron overloaded hydrogen and helium nuclei. These neutron-overloaded nuclei are produced in reactions of tritium beams on a heavy hydrogen and tritium target.

Experimental data on the shock compression, temperature, and absorptivity of gaseous deuterium with an initial density close to its value in the liquid state were obtained on a spherical explosion shock-wave generator in a pressure range of 80–90 GPa. The obtained results are compared with the existing experimental and theoretical data.

The results of the design study of an advanced scheme for the 14-MeV intense neutron source based on muon-catalyzed fusion ({mu}CF) are presented. A pion production target (liquid lithium) and a synthesizer [liquid deuterium-tritium (D-T) mixture] are considered. Negative pions are produced inside a 17/7 T magnetic field by an intense (2-GeV,12-mA) deuteron beam interacting with the 150-cm-long, 0.75-cm-radius lithium target. Muons from the pion decay are collected in the backward direction and stopped in the D-T mixture of the synthesizer. The synthesizer has the shape of a 10-cm-radius sphere surrounded by two 0.03-cm-thick titanium shells. At 100 {mu}CF events/muon, it can produce up to 10{sup 17}n/s of 14-MeV neutrons. A quasi-isotropic neutron flux up to 10{sup 14} n/cm{sup 2}.s{sup -1} can be achieved in the test volume of {approx}2.5 l with an irradiated surface of {approx}350 cm{sup 2}. The thermophysical and thermomechanical analyses show that the technological limits are not exceeded.

Equilibrium pressures of protium and deuterium desorption over a two-phase area of monohydride-vanadium dihydride were measured. Temperature measurement range was 300–635 K and the pressure range 1–500 MPa. Obtained temperature-dependences of fugacities within the given measurement range are: lgf(MPa) = −2152/T+ 6.6 and lgf(MPa) = −2575/T + 7.4 for protium and deuterium, respectively. The values of enthalpy and entropy for vanadium dihydride phase formation were calculated from obtained relations. Using expressions obtained for fugacities and literature data on hydrogen imperfection the pressures, which can be obtained with vanadium dihydride employed in thermodesorption hydrogen sources, were estimated. Taking into account that due to deterioration in strength properties of the used structural materials, the heating temperature of the load-bearing body is limited to ∼973 K, maximal calculated pressure, which can be obtained with such sources as ≈1820 MPa for protium and ≈2220 MPa for deuterium.

Experiments on the mixing of liquid hydrogen and deuterium have been performed in a specially designed apparatus. We estimate the value of the heat of solution to be 17 J/g. The results confirm the conclusions of our previous papers about the existence of a heat of solution when liquid hydrogen and deuterium are mixed.

There are two constituents that determine success in synthesizing vanadium hydride: activation and supply of hydrogen to vanadium at an appropriate pressure. The most efficient activation has been found to occur, depending on the vacuum produced in a facility, in temperature ranges between 550 and 750 K or above 850 K. Dependencies of equilibrium sorption pressures of protium and deuterium over respective dihydride phases of vanadium are provided. At an atomic ratio of 0.85 ≤ X/V ≤ 1.5 (X is protium or deuterium), they take the following form, respectively, log P ( Pa ) = − 2160 / T + 12.8 and log P ( Pa ) = − 2480 / T + 13.6 . At higher hydrogen concentrations, coefficients in the Van’t Hoff equation are observed to depend on the hydrogen content. Based on the obtained experimental data on equilibrium sorption pressures and available literature data on isotopic effects, the same dependence of sorption pressure has been calculated for vanadium ditritide. For T/V = 0.85 , it is expressed as: log P ( Pa ) = − 2490 / T + 13.4 . Dependencies of equilibrium sorption pressures for all the three hydrogen isotopes at temperatures between 273 and 323 K and ratios of 0.85 ≤ ( H, D or X ) / V ≤ 1.9 are presented in the form of diagrams.

The installation is described which allows to perform measurements of kinetic parameters of protium and deuterium permeation through construction materials in a wide range of temperatures (20–1000°C) and pressures (1.3 · 10−3–300 MPa). The values of kinetic parameters of hydrogen permeability are presented for alloys 12Cr18Ni10Ti, CrNi35WTiAl, 37Cr12Ni8Mn8MoVNb, CrNi52MoWNbCoTiAl, CrNi50MoWNbCoTiAl in the temperature range of 200 to 800°C. The work was carried out at pressures of diffusion-pure hydrogen P = 10–13 MPa. The values of kinetic parameters of tritium permeation through materials: steel 20, 12Cr18Ni10Ti, alloys Al 6Mg Mn and Al Mn are presented in the temperature range of 25 to 250°C. The work was carried out at absolute pressure of gaseous tritium P = 0.02–0.06 MPa. The method of such an investigation is described.

International audience; The $^{5}$H system was produced in the $^{3}$H(t, p) $^{5}$H reaction studied at small CM angles with a 58MeV tritium ion beam. High statistics data were used to reconstruct the energy and angular correlations between the $^{5}$H decay fragments. A broad structure in the $^{5}$H missing-mass spectrum showing up above 2.5MeV was identified as a mixture of the $3/2^+$ and $5/2^+$ states. The data also present an evidence that the $1/2^+$ ground state of $^{5}$H is located at about 2MeV. Then, the $^{5}$H and $^{5}$He systems were explored by means of transfer reactions occurring in the interactions of 132MeV $^{6}$He beam nuclei with deuterium. In the $^{2}$H( $^{6}$He, $^{3}$H) reaction a T = 3/2 isobaric analog state of $^{5}$H in $^{5}$He was observed at an excitation energy of 22.0±0.3MeV with a width of 2.5±0.3MeV.

The H-4 resonance was investigated in the transfer reactions H-2(t,p)H-4 and H-3(t,d)H-4 using cryogenic liquid targets of deuterium and tritium and 58 MeV triton beam. The multidetector system with a large angular acceptance was used to measure the recoil protons and deuterons in coincidences with tritons or neutrons from the decay of H-4. Data analysis involved careful considerations made for the competing processes of final state interaction and quasifree scattering. The experimental data show a peak with resonance parameters E-res = 3.05 +/- 0.19 MeV and Gamma(obs) = 4.18 +/- 1.02 MeV. The pole of S-matrix corresponding to the physical values of energy and width, E-0 = 1.99 +/- 0.37 MeV and Gamma(0) = 2.85 +/- 10.3 MeV, has been extracted. (C) 2004 Elsevier B.V. All rights reserved.

Equilibrium pressure of sorption and desorption have been measured over vanadium hydride of the composition VX0,8-2,0 where X is H2, D2 or their mixture. The work has been done using electrolytic vanadium VEL — 2. Temperature dependencies of desorption equilibrium pressures for vanadium hydride VX1,0-1,9 in a pressure range 1 — 550 bar were found to be : 1g P(atm.) = -2085/T + 7,5 and 1g P(atm.) = -2454/T + 8,2 for protium and deuterium, respectively. Temperature dependence of pressure, obtained for mixtures H2 and D2, are between those found for pure D2 and H2 but shifted toward dependence for D2. Based on the found dependencies, the enthalpy of relevant vanadium dihydride phases generation was calculated.