No abstract available

No abstract available

[en] We demonstrate experimentally the guiding of cold and slow ND₃ molecules along a thin charged wire over a distance of ∼0.34 m through an entire molecular beam apparatus. Trajectory simulations confirm that both linear and quadratic high-field-seeking Stark states can be efficiently guided from the beam source up to the detector. A density enhancement up to a factor 7 is reached for beams with velocities ranging down to ∼150 m/s generated by the rotating nozzle technique.

[en] A numerical method is given for the evaluation of the electric field gradient at the deuteron in HD. The method is suitable for computations with the most accurate wavefunctions of HD available at the present time. As an illustration, the method is applied to the computation of the electric field gradient in HD with the use of a 20-term electronic wave function. (author)

[en] As a stable boron source to be used for performing boronization of the inner walls of a thermonuclear reactor, use of decaborane deuteride has been studied. Decaborane deuteride is produced by heat-decomposing and polymerizing diborane deuteride. The production device comprises a heating means for heating diborane deuteride gas, a cooling means for cooling the gas from the heating means and a means for recovering decaborane deuteride just after condensation in the cooling means. Just after introducing the diborane deuteride gas to the heating means, sending the gas from the heating means to the cooling means and condensing the decaborane deuteride in the cooling means, the decaborane deuteride is recovered. Highly purified decaborane deuteride can be obtained and is used suitably as a stable boron source such as for boronization of the inner wall of the thermonuclear reactor. (N.H.)

[en] A four electrode electrostatic trap geometry is demonstrated that can be used to combine a dipole, quadrupole, and hexapole field. A cold packet of ¹⁵ND₃ molecules is confined in both a purely quadrupolar and hexapolar trapping field and additionally, a dipole field is added to a hexapole field to create either a double-well or a donut-shaped trapping field. The profile of the ¹⁵ND₃ packet in each of these four trapping potentials is measured, and the dependence of the well-separation and barrier height of the double-well and donut potential on the hexapole and dipole term are discussed

[en] We propose a controllable high-efficiency electrostatic surface trap for cold polar molecules on a chip by using two insulator-embedded charged rings and a grounded conductor plate. We calculate Stark energy structure pattern of ND3 molecules in an external electric field using the method of matrix diagonalization. We analyze how the voltages that are applied to the ring electrodes affect the depth of the efficient well and the controllability of the distance between the trap center and the surface of the chip. To obtain a better understanding, we simulate the dynamical loading and trapping processes of ND₃ molecules in a |J,KM〉 = |1, − 1〉 state by using classical Monte—Carlo method. Our study shows that the loading efficiency of our trap can reach ∼ 88%. Finally, we study the adiabatic cooling of cold molecules in our surface trap by linearly lowering the potential-well depth (i.e., lowering the trapping voltage), and find that the temperature of the trapped ND3 molecules can be adiabatically cooled from 34.5 mK to ∼ 5.8 mK when the trapping voltage is reduced from −35 kV to −3 kV. (atomic and molecular physics)

[en] The promise of an abundant energy supply has inspired many approaches to controlling thermal nuclear fusion. One approach to initiating fusion is to use a hypervelocity projectile to impact a deuterium--tritium (DT) pellet. For this purpose, magnetic accelerators have been propsed for accelerating macroparticles to velocities greater than 100 km/s. This paper summarizes a portion of a study that assesses the feasibility of accelerating a 0.1-g payload to a velocity of 150 km/s or more. In that study it was concluded that magnetic-gradient and railgun accelerators could achieve the goal. The critical factors that limit the design and operation of railgun accelerators are discussed. These factors are combined with a simulation code to assess potential railgun performance in this regime

[en] The specific anisotropic interactions between HD molecules stemming from the fact that the HD molecules rotate not around their geometric centers can account for the structure anomalies found in experiment. At comparatively moderate pressures (below 10 kbar) the specific anisotropic interactions compare with the electrical quadrupole-quadrupole interaction and can be the decisive factor in forming the eventual orientational order parameter to appear in a pressuredriven phase transition

[en] We attempt to find a simple procedure for evaluating the electric field gradient at the position of a deuteron in a molecule by performing a set of sample calculations on the HD molecule. Starting from a set of simple molecular orbital or valence bond functions, we calculate the expectation values of the DEFG (deuterium electric field gradient) values with an accuracy of about 10%. By making use of a variation--perturbation procedure we evaluate correction terms which reduce the errors to 1% or 2%. An essential feature in the variation-perturbation method is the use of 3d atomic orbitals with unusually large orbital exponents (q = 7). We feel that our methods are applicable to larger molecules also