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An experiment demonstrating the production of double-Lambda hypernuclei in (K(-),K(+)) reactions on (9)Be was carried out at the D6 line in the BNL alternating-gradient synchrotron. The technique was the observation of pions produced in sequential mesonic weak decay, each pion associated with one unit of strangeness change. The results indicate the production of a significant number of the double hypernucleus (4)(double Lambda)H and the twin hypernuclei (4)(Lambda)H and (3)(Lambda)H. The relevant decay chains are discussed and a simple model of the production mechanism is presented. An implication of this experiment is that the existence of an S = -2 dibaryon more than a few MeV below the double Lambda mass is unlikely.

The spin-orbit splitting of Lambda single-particle states in (13)(Lambda)C was measured. The 13C(K-,pi(-))(13)(Lambda)C reaction was used to excite both the 1/2(-) and 3/2(-) states simultaneously, which have predominantly 12C(0(+)) x p(Lambda) configuration. gamma rays from the states to the ground state were measured in coincidence with the pi(-)'s, by which ls splitting was found to be 152+/-54(stat)+/-36(syst) keV. The value is 20-30 times smaller than exhibited by the ls splitting in the nuclear shell model. This value gives us new insight into the YN interaction.

Results from I(, +elastic and inelastic scattering from ' C and Ca are reported. The data were all taken at an incident momentum of 800 MeV/c over an angular range from 2' to 38'. The elastic data are compared to first-order optical model calculations in coordinate and momentum space; good qualitative agreement is obtained. The inelastic data (from ' C only) are compared to distorted-wave Born approximation calculations, and good agreement is found if "realistic" inelastic transition densities are used. Although a first-order optical potential description does not describe the data fully, there are strong indications of the increased penetrability of K+ over E in this energy range. NUCLEAR REACTIONS ' C(E -E )' C Ca(-E , IC )Ca, F--=442 MeV (800 MeV/c), measured o. (I9) for elastic and inelastic scattering, compared to optical model and DWBA calculations, deduced optical potential parameters; 8=2' -38', 68= 1'.

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The total cross sections for K+ mesons on carbon and deuterium nuclei have been measured at eleven momenta in the range 450-740 MeV/c. The experimental technique was of the standard transmission type. The K+ meson is the least strongly interacting of available hadronic probes, with a long mean free path in nuclear matter. At low incident momentum the K+K interaction is dominated by the Szz phase shift and varies slowly with energy. These characteristics make the K+ an ideal tool for probing the nuclear volume to reveal nuclear medium effects. Measurements of the ratio of the total cross sections, per nucleon, of K+-C to K+-d have been suggested as a way to reveal effects of the nuclear medium. The total cross section ratios are found to lie significantly above those predicted by the usual nuclear medium corrections. This suggests that novel phenomena are taking place within the nucleus. Several models which incorporate such phenomena are discussed, including nucleon swelling, " mass rescaling, nuclear pions, and relativistic efFects.

In the FRX-C/T experiment [Proceedings of the 9th Symposium for Engineering Problems of Fusion Research (IEEE, New York, 1981), p. 1751], field-reversed configuration (FRC) plasmas have been formed in, and launched from, a field-reversed theta-pinch source and subsequently trapped in an adjacent confinement region. No destructive instabilities or enhanced losses of poloidal flux, particles, or thermal energy are observed for FRC total trajectories of up to 16 m. The observed translation dynamics agree with two-dimensional magnetohydrodynamic (MHD) simulations. When translated into reduced external magnetic fields, FRC’s are observed to accelerate, expand, and cool in partial agreement with adiabatic theory. The plasmas reflect from an external mirror and after each reflection, the axial kinetic energy is reduced by approximately 50%. Because of this reduction, FRC’s are readily trapped without the need of pulsed gate magnet coils.

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