This paper reports the results of a study to maximize the ion temperature of the plasma generated by a gas-injected washer gun. We characterize the gun discharge and the plasma output as a function of the controllable gun parameters. For hydrogen we find a maximum ion temperature of 100 eV with typical densities ranging from 2×1011 to 5×1012 cm−3. A primary feature of the pulsed gun discharge is the observation of large amplitude rf fluctuations on the cathode voltage. The fluctuation amplitude varies with discharge current and with the quantity of injected gas. We show that the scaling of the fluctuation level with gun parameters is in agreement with that expected of an unstable beam-plasma system. We find a linear relation between the square of the fluctuation amplitude and the product of the plasma density times the ion temperature of the plasma output nTi, suggesting a stochastic wave-induced heating mechanism.

The three-dimensional mode structure of the drift cyclotron loss-cone (DCLC) instability is characterized in an axisymmetric mirror machine. It is shown, for this experiment, that (1) the azimuthal mode structure does not assume the geometry associated with an azimuthal normal mode φ̃=f (r,z)exp(imθ) with a single integral value of m, (2) the presence of a cool-ion plasma stream does not, in general, stabilize the mode globally, and (3) the axial mode characteristics have finite structure.

Experiments performed in a single-ended Q-machine examine the effect of a large-amplitude electrostatic lower hybrid wave on the dispersion of the current-driven ion acoustic instability. Nonlinear coupling of the modes provides a mechanism for suppression of the ion acoustic instability through a reduction in ion-acoustic mode phase velocity and an associated increase in ion Landau damping. An analysis which includes the effects of electron collisional or transit-time damping on the interaction is presented. This analysis demonstrates the resonant character of the interaction and allows quantitative evaluation of the lower hybrid power levels necessary for stabilization of the ion acoustic mode.

A miniature analyzer probe is described for measuring the component of the ion energy distribution perpendicular to the confining magnetic field in a hot-ion plasma. The analyzer employs the magnetic field to exclude electrons due to their small gyroradii. Ions are selectively retarded by a positively biased collector. The limits on the operating regime of this analyzer are calculated. The device is used in the MIX 1 mirror machine where we measure an ion temperature of ∼100 eV and plasma density ≳1011 cm−3.

An additional coil between the plasma source and the mirror cell prefans incoming plasma to map it directly into the well-known twisted bow-tie shape and thus avoids reshaping drifts generated in conventional min-B mirror machines. This reduces vacuum chamber size requirements and eliminates any drift reshaping delay. Wound in series with the standard quadrupole loffe bar set, this dual-coil system features end connections which contribute no field on axis.

Abstract3‐Chlor‐1,2‐dithiolium‐chloride (I) reagieren mit Thioessigsäure (II) in Benzol über die Zwischenstufe (III) zu den Trithionen (IV).

Abstract3‐Chlor‐1,2‐dithiolium‐chloride (I) reagieren mit N,N‐Dichlor‐benzolsulfonamid (IIa), ‐N′,N′‐dimethylsulfamid (IIb) oder N,N‐Dichlor ‐urethan (IIc) in Methylenchlorid zu N‐substituierten 3‐Imino‐1,2‐dithiolen (III).