At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ approx. = 1000 to 2000 s) and very high I/sub sp/ (3 x 10/sup 7/ s) appear feasible and have efficiencies on the order of 50% for annihilation energy to propulsion energy conversion. At I/sub sp/'s of around 15,000 s, however, it may be that only the kinetic energy of the charged nuclear fragments can be utilized for propulsion in engines of ordinary size. An estimate of this kinetic energy was made from known pieces of experimental and theoretical information. Its value is about 10% of the annihilation energy. Control over the mean penetration depth of protons into matter prior to annihilation is necessary so that annihilation occurs in the proper region within the engine. Control is possible by varying the antiproton kinetic energy to obtain a suitable annihilation cross section. The annihilation cross section at low energies is …

The Schroedinger Integral Equation is derived for an N-body system, and solutions for required Green's functions are obtained. The initial method of numerical solution has yielded the correct ground states and lower excited states of He (test case) and dt..mu... Steps are being taken to improve the numerical accuracy.

The effect of transverse displacements of combined function magnets is investigated where the disperion in not matched due to roll. This dispersion function is perturbed by displacement of combined function magnets either singly or coherently. In the latter case the effect of a systematic (or DC) offset of magnets is examined. This type of error can occur due to systematics in the placement or the readout of Beam Position Monitors or equivalently by correcting the orbit of a beam of the wrong momentum with respect to the Arc magnet excitation. 5 refs., 18 figs.

For antiproton energies of several eV or less, annihilation in matter occurs through atomic rearrangement processes in which the antiproton becomes bound to a nucleus prior to annihilation. Existing calculations of the antiproton-hydrogen atom rearrangement cross section are semiclassical and employ the Born-Oppenheimer approximation. They also employ various arguments in regard to the behavior of the system when the Born-Oppenheimer approximation breaks down at small antiproton-proton separations. These arguments indicate that rearrangement is essentially irreversible. In the present study, a detailed investigation was made of the antiproton-hydrogen atom system when the Born-Oppenheimer approximation breaks down. The results of this study indicate that the previous arguments were approximately correct, but that there is a significant probability for rearrangement reversing prior to annihilation. This probability is estimated to be about 20%. 8 refs., 4 figs., 2 tabs.

This paper reports the results of calculations of electron impact ionization cross sections for a variety of heavy ions using a distorted wave Born-exchange approximation. The target is described by a Hartree-Fock wavefunction. The scattering matrix element is represented by a triple partial wave expansion over incident, scattered, and ejected (originally bound) continuum states. These partial waves are computed in the potentials associated with the initial target (incident and scattered waves) and the residual ion (ejected waves). A Gauss integration was performed over the distribution of energy between the two final state continuum electrons. For ionization of closed d- and f-subshells, the ejected f-waves were computed in frozen-core term-dependent Hartree-Fock potentials, which include the strong repulsive contribution in singlet terms which arises from the interaction of an excited orbital with an almost closed shell. Ground state correlation was included in some calculations of ionization of d/sup 10/ subshells.

This paper presents a design chart to aid designers in the selection of a wall thickness for long cylindrical shells having atmospheric pressure outside the shell and a pressure less than atmospheric inside the shell. The chart indicates a conservative value for the minimum wall thickness for a given shell diameter and material when the shell is completely evacuated.

The Tritium Systems Test Assembly (TSTA) at the Los Alamos National Laboratory has been operating with tritium since June 1984. Presently there are some 50 g of tritium in the main processing loop. This 50 g has been sufficient to do a number of experiments involving the cryogenic distillation isotope separation system and to integrate the fuel cleanup system into the main fuel processing loop. In January 1986 two major experiments were conducted. During these experiments the fuel cleanup system was integrated, through the transfer pumping system, with the isotope separation system, thus permitting testing on the integrated fuel processing loop. This integration of these systems leaves only the main vacuum system to be integrated into the TSTA fuel processing loop. In September 1986 another major tritium experiment was performed in which the integrated loop was operated, the tritium inventory increased to 50 g and additional measurements on the performance of the distillation system were taken. In the period June 1984 through September 1986 the TSTA system has processed well over 10/sup 8/ Ci of tritium. Total tritium emissions to the environment over this period have been less than 15 Ci. Personnel exposures during this period have totaled less than …

Investigations of the possibilities for inflation using the four dimensional models inspired by superstring theory is reported and discussed in the context of related work. 34 refs., 1 fig.

The electron-photon transport code SANDYL has been used to calculate the x-ray flux for a simplified Flash X-Ray Machine (FXR) bullnose geometry. Four different thicknesses (24.5, 36.75, 49, and 61.25 mils) were used for the tantalum bremsstrahlung target in order to study the effect of target thickness on the FXR output. The calculations were performed for a parallel 17 MeV electron beam, and the resulting angular distributions were then used to compute the forward flux for the more realistic case of a converging beam. Over the range of thicknesses studied, the x-ray energy content per steradian on axis was essentially independent of target thickness. The main reason for this is that, while the total x-ray flux coming out of the target increases with increasing target thickness, the angular width of that flux also increases. The implications for target wheel design are discussed. 3 refs., 7 figs.

During the summer of 1985, we replaced the WNR T-shaped target/moderator scheme with the LANSCE split-target/flux-trap-moderator design. The intent of this 'LANSCE upgrade' was to increase (to 12) the number of neutron beam lines serviced simultaneously, and to enhance the target area shielding and target system to accept 200 ..mu..A of 800-MeV protons. The four LANSCE moderators consist of three (chilled) water moderators, and a liquid hydrogen (20 K) moderator. The LANSCE target is machinable tungsten.

The performance of the Intense Pulsed Neutron Source (IPNS) Accelerator System is reported, including an increase in average beam current to 13.4 microamperes and increased reliability to 93.2%. Brief discussions are given for the performance of the major accelerator subsystems, including the H/sup -/ ion source and preaccelerator, the 50 MeV linac, and the synchrotron and its subsystems. (LEW)

This report contains the results of calculations for a resized nozzle on the D-Zero test cryostat. The nozzle neck in the inner vessel with be 6-inch schedule 10S pipe and 8-inch 10S will be used for the outer vessel. On top of the nozzle will be placed the D-Zero Endcap Calorimeter signal board feedthru dewar box. This box weighs approximately 250 lbs but the weight was conservatively taken to be 500 lbs. The allowable pressure from above does not exceed 15 psig per ASME, but it does exceed 7.5 psig required by CGA-341 therefore reinforcement is not required. Note that the reinforcement provided by the nozzle neck in combination with the excess shell thickness is probably sufficient to satisfy the ASME requirements.

In the last few years the development of tandem-discharge hydrogen-negative-ion-source systems has proceeded along both experimental and theoretical lines. To some extent these developments have proceeded independently, either the available theoretical model was inadequate to account for a specific geometrical configuration, or the experimental data was not sufficient to provide adequate input parameters for calculation. In the tandem system described here the electron temperature, electron density, and other relevant parameters have been obtained for a high-density system whose electron densities range up to 3 - 5 x 10/sup 12/ electrons cm/sup -3/. The model calculation for the atomic processes has been extended to include both electron density and electron temperature spatial variations through the second chamber. These spatial variations are essential for an adequate interpretation of tandem systems where steep density gradients may occur beyond the magnetic filter region. In this paper we shall combine the experimental density data with the new spatially dependent atomic model for the purpose of attempting a correlation of the observed and calculated current densities. 9 refs., 8 figs., 3 tabs.

We discuss the acceleration of magnetically-confined plasma rings to provide a driver for ICF. The acceleration of plasma rings is predicted to be efficient and following focusing, to generate ion-bombardment power in the range 10/sup 15/ to 10/sup 16/ W/cm/sup 2/ at a total deposition energy of multimegajoules. The simplicity of plasma ring accelerator suggests that a 5 MJ (on target) driver would cost in the range 1 to 5 $/joule. First experimental tests of the accelerator are described.