Observation of Efficient Lower Hybrid Current Drive at High Density in Diverted Plasmas on the Alcator C-Mod Tokamak.

Efficient lower hybrid current drive (LHCD) is demonstrated at densities up to n[over ¯]_{e}≈1.5×10^{20} m^{-3} in diverted plasmas on the Alcator C-Mod tokamak by operating at increased plasma current-and therefore reduced Greenwald density fraction. This density exceeds the nominal "LH density limit" at n[over ¯]_{e}≈1.0×10^{20} m^{-3} reported previously, above which an anomalous loss of current drive efficiency was observed. The recovery of current drive efficiency to a level consistent with engineering scalings is correlated with a reduction in density shoulders and turbulence levels in the far scrape-off layer. Concurrently, rf wave interaction with the edge and/or scrape-off-layer plasma is reduced, as indicated by a minimal broadening of the wave frequency spectrum measured at the plasma edge. These results have important implications for sustaining steady-state tokamak operation and indicate a pathway forward for implementing efficient LHCD in a reactor.

Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U.

A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.

Effects of magnetic shear on toroidal rotation in tokamak plasmas with lower hybrid current drive.

Application of lower hybrid (LH) current drive in tokamak plasmas can induce both co- and countercurrent directed changes in toroidal rotation, depending on the core q profile. For discharges with q(0) <1, rotation increments in the countercurrent direction are observed. If the LH-driven current is sufficient to suppress sawteeth and increase q(0) above unity, the core toroidal rotation change is in the cocurrent direction. This change in sign of the rotation increment is consistent with a change in sign of the residual stress (the divergence of which constitutes an intrinsic torque that drives the flow) through its dependence on magnetic shear.

Modification of ordinary-mode reflectometry system to detect lower-hybrid waves in Alcator C-Mod.

Backscattering experiments to detect lower-hybrid (LH) waves have been performed in Alcator C-Mod, using the two modified channels (60 GHz and 75 GHz) of an ordinary-mode reflectometry system with newly developed spectral recorders that can continuously monitor spectral power at a target frequency. The change in the baseline of the spectral recorder during the LH wave injection is highly correlated to the strength of the X-mode non-thermal electron cyclotron emission. In high density plasmas where an anomalous drop in the lower hybrid current drive efficiency is observed, the observed backscattered signals are expected to be generated near the last closed flux surface, demonstrating the presence of LH waves within the plasma. This experimental technique can be useful in identifying spatially localized LH electric fields in the periphery of high-density plasmas.

Energetic ion loss detector on the Alcator C-Mod tokamak.

A scintillator-based energetic ion loss detector has been successfully commissioned on the Alcator C-Mod tokamak. This probe is located just below the outer midplane, where it captures ions of energies up to 2 MeV resulting from ion cyclotron resonance heating. After passing through a collimating aperture, ions impact different regions of the scintillator according to their gyroradius (energy) and pitch angle. The probe geometry and installation location are determined based on modeling of expected lost ions. The resulting probe is compact and resembles a standard plasma facing tile. Four separate fiber optic cables view different regions of the scintillator to provide phase space resolution. Evolving loss levels are measured during ion cyclotron resonance heating, including variation dependent upon individual antennae.

Nosology of atypical depression.

A review of the literature on atypical depression indicated three relatively separate usages for the term: anxiety or phobic symptoms additional to depression, reversed functional shift, and non-endogenous depression. A sample of 160 out-patient depressives was rated on a variety of diagnostic systems measuring these concepts. Inter-relationships between groups selected by the three definitions were found to be low. In addition, although there was moderate consistency within different definitions of endogenous depression and of additional anxiety, reversed functional shift symptoms did not correlate well with each other. These findings suggest that atypical depression may be of limited value as a specific diagnosis within non-psychotic depression.

PEP4 gene function is required for expression of several vacuolar hydrolases in Saccharomyces cerevisiae.

The pep4-3 mutation results in a 90-95% reduction in the levels of five vacuolar hydrolases in yeast, including proteinases A and B, carboxypeptidase Y, RNase(s) and the repressible alkaline phosphatase. The mutation is without effect on two secreted glycoproteins, on an enzyme of the vacuolar membrane, and on a proteinase located outside of the vacuole. Mutations at the PEP4 locus exhibit a dosage effect on the levels of some, but not all, of the enzymes whose expression requires the function of the gene.

Influence of acetylator phenotype on antidepressant effects of phenelzine.

Acetylator phenotype, determined by blood levels after sulphadimidine, was related to outcome in a controlled trial of phenelzine in patients with depression and mixed anxiety depression. Slow acetylators showed more improvement and greater phenelzine-placebo differences than did fast acetylators, at two, four and six weeks. A tendency towards faster acetylation was observed in subjects with previous increased alcohol intake. Acetylator phenotype was not related to other symptom, diagnostic or history data.

Response to phenelzine and amitriptyline in subtypes of outpatient depression.

Outpatients with depression and mixed anxiety-depression were treated for six weeks with phenelzine sulfate, amitriptyline hydrochloride, or placebo in a controlled trial. Both active drugs were superior to placebo and were closely comparable in efficacy. Interactions were examined between drug response and classifications based on three different usages of the term atypical depression: additional anxiety or phobic symptoms, atypical functional shift, and nonendogenous depression. Some additional related classifications were also included. There was a tendency for phenelzine to have stronger effects in patients with additional anxiety and without evidence of chronic characterological depression. However, interactions were relatively few. These findings suggest that the two classes of antidepressant affect similar clinical subgroups within the outpatient depressive spectrum, with only relatively weak differences.

Phenelzine and amitriptyline: effects on symptoms of neurotic depression.

A double-blind controlled trial of phenelzine, amitriptyline and placebo was carried out in out-patients suffering from depression or mixed anxiety and depression. After six weeks treatment both active drugs were clearly superior to placebo and of similar efficacy; therapeutic effects started to appear at two weeks. Comparisons on symptom ratings showed that both drugs acted as true antidepressants, producing their greatest effects on ratings of depressive mood and thought content. There were additional weak differences, phenelzine producing more improvement on anxiety ratings, while amitriptyline gave greater effects on depressive impairment of work and interests and anergia. Analyses showed little evidence of clinical subgroups responding preferentially to either drug. The findings indicate that MAO inhibitors and tricyclic antidepressants have more closely similar clinical effects than has been thought and that either may be a useful treatment for these patients who are often considered to respond poorly to antidepressant drug treatment.

A case of self-inflicted eye injuries.

The case is described of a young man who repeatedly injured his left eye. There was a history of previous deliberate self-injury and of childhood epilepsy. A diagnosis of borderline personality disorder was made. Similarities to other reported patients who injured their eyes, to "wrist-cutters," and to "delicate self-cutters" are discussed.

Depressive classification and prediction of response to phenelzine.

A variety of depressive classifications were used to predict response to four weeks' treatment with phenelzine. Better response was found in outpatients rather than inpatients, in atypical depressives, in less severe depressives with a pattern of anxiety and other neurotic symptoms, and in groups characterized as hostile and agitated. The findings, although a little patchy, gave clear support to the concept of a specific clinical group responsive to MAO inhibitors.

Chlorodyne dependence.

Eight cases of chlorodyne dependence seen in a London drug clinic are described. These cases and the results of an inquiry among pharmacies in central and south London suggest that this form of drug dependence is commoner among younger people than has been supposed and that the total number of chlorodyne-dependent people in Greater London may exceed 1,000. The prognosis for cure is poor. We recommend that the supply of chlorodyne, now available without prescription to the public, should be restricted.