[en] The (p,d) reaction was studied for the first time at 800 MeV on seven targets ranging from ⁷Li to ⁴⁰Ca. The experimental resolution (approx. 400 keV) attained was sufficient to observe many discrete levels in each of the residual nuclei. A modified version of the one-nucleon model successfully describes the magnitude and angular dependence of almost all of the transitions observed. A specific counter example to the two-nucleon model of the reaction mechanism is suggested. The calculations are also sensitive to the neutron single-particle wave function, in accordance with the expectation that the high-momentum components of this wave function are probed at higher bombarding energies. States that have never been seen before were strongly populated in the high excitation region (up to 25 MeV) of some of the residual nuclei. The relative intensities of the other levels observed suggest that coupled-channels mechanisms play an important role for some of these states. Explicit calculations were performed to confirm this for several examples. The first high-resolution measurements of the (π⁺,p) reaction were also performed on ⁶Li, ⁷Li, ¹²C, and ¹³C at pion bombarding energies on and off the pion-nucleon resonance. Calculations employing a one-nucleon model of the reaction mechanism similar to the model successfully used for the (p,d) reaction are unable to account for transitions in the (π⁺,p) reaction. It is, however, unclear whether this failure is due to a fundamental inadequacy of the model or improper treatment of details in the calculations. A striking similarity was observed in the spectra of the (π⁺,p) and 800-MeV (p,d) reactions on the same target; this result implies a similar mechanism for the two reactions. 120 references, 97 figures, 15 tables

[en] Distribution functions that are separable in energy and pitch angle allow analytical calculation of one or two velocity-space integrals that appear in the linear theory of certain microinstabilities

[en] Estimates of the localizability of electron-cyclotron heating power are made for the Compact Ignition Tokamak. A particular heating scenario is examined, namely, the fundamental O-mode, injected nearly perpendicular to the toroidal magnetic field. The absorption depth due to finite T_e is very small, about 1 cm, near the q = 2 surface. Absorption is even better localized near q = 1. Several issues that might lead to degraded localizability are reviewed. Use of an intense, pulsed microwave source is the only issue with a possibly significant impact. 3 refs

[en] To better understand and predict tandem-mirror experiments, we are building a comprehensive Mirror Equilibrium Radial Transport and Heating (MERTH) code. In this paper we first describe our method for developing the code. Then we report our plans for the installation of physics packages for electron- and ion-cyclotron heating of the plasma

[en] Optimum launch parameters are determined for localized electron-cyclotron current drive near the magnetic axis and the q=2 surface by solving several minimization problems. For central current drive, equatorial and bottom launch are compared. Localized current drive near q=2 is studied for equatorial launch and for an alternative outside launch geometry that may be better for suppressing tearing modes and controlling disruptions. 6 refs., 2 figs

[en] The theory of scattering by drift-wave density fluctuations is applied to electron-cyclotron heating (ECH) in the Compact Ignition Tokamak (CIT). It is found for CIT that the scattering angles are small and have a Gaussian distribution. An analytic result is given for the average number of scattering events suffered by a ray during propagation through the turbulence layer; this average number is 1.3 for the turbulence level expected in CIT. Localizability of ECH power in CIT is also studied for two choices of steering mirror. Better access to outer flux surfaces and better localization is achieved if the power is steered within a poloidal plane. 7 refs., 3 figs

[en] The motion of ions in a nonuniform magnetic field and a single electrostatic wave is treated in our study of a possible saturation mechanism of the dissipative trapped-ion instability in a tokamak. A theory involving the overlap of bounce resonances predicts the main features found in our numerical integration of the equations of motion. Ions in a layer near the trapped-circulating boundary move stochastically. This motion leads to nonlinear stabilization mechanisms which are described qualitatively

[en] One studies the dynamical system described by the Hamiltonian H = H₀ + EPSILON V, where H₀ = ¹/₂ p² - cos x, V = - cos (lambda x - Ωt). One encounters this system in a number of problems of practical importance. In addition, the system has intrinsic interest for the theory of adiabaticity and stochasticity. The invariant action J of the unperturbed Hamiltonian H₀ is subject to strong modification or destruction because of the perturbation EPSILON V. Absence of an invariant (i.e., stochasticity) occurs in a phase space region whose size and shape vary with the three parameters EPSILON, lambda, Ω. Previous studies have varied the amplitude of a perturbation (our epsilon); one emphasizes the strong dependences on the space (lambda) and time (Ω) scales of the perturbation. Results show that a perturbation is most effective at causing stochastic motion if its space and time scales are comparable (lambda - 1, Ω - 1) to those in the unperturbed Hamiltonian H₀

[en] A single electrostatic wave in a magnetoplasma causes stochastic ion motion in several physically different situations. Various magnetic fields (uniform, tokamak, and mirror) and various propagation angles with respect to the field have been studied. A brief review of this work shows that all situations can be understood using the concept of overlapping resonances. Analytical calculations of the wave amplitude necessary for stochasticity have been carried out in some cases and compared with computer and laboratory experiments. In the case of an axisymmetric mirror field the calculations predict stochastic motion of ions with energy below a threshold that depends weakly on the wave amplitude and on the scale lengths of the magnetic field. Studies with an azimuthally asymmetric field show that the asymmetry causes substantial changes in the motion of some ions

[en] Hamiltonian methods are used to study the motion of a particle in the field BZ and a single electrostatic wave. The particle motion is studied by numerically integrating the equations of motion. Diagrams of various particle trajectories are given