In this article we present the design and test results of the most powerful, fast linear transformer driver (LTD) stage developed to date. This 1-MA LTD stage consists of 40 parallel RLC (resistor R, inductor L, and capacitor C) circuits called ''bricks'' that are triggered simultaneously; it is able to deliver $1 MA current pulse with a rise time of $100 ns into the $0:1-Ohm matched load. The electrical behavior of the stage can be predicted by using a simple RLC circuit, thus simplifying the designing of various LTD-based accelerators. Five 1-MA LTD stages assembled in series into a module have been successfully tested with both resistive and vacuum electron-beam diode loads.

We present observations for 20-MA wire-array z pinches of an extended wire ablation period of 57%+/-3% of the stagnation time of the array and non-thin-shell implosion trajectories. These experiments were performed with 20-mm-diam wire arrays used for the double- z -pinch inertial confinement fusion experiments [M. E. Cuneo, Phys. Rev. Lett. 88, 215004 (2002)] on the Z accelerator [R. B. Spielman, Phys. Plasmas 5, 2105 (1998)]. This array has the smallest wire-wire gaps typically used at 20 MA (209 microm ). The extended ablation period for this array indicates that two-dimensional (r-z) thin-shell implosion models that implicitly assume wire ablation and wire-to-wire merger into a shell on a rapid time scale compared to wire acceleration are fundamentally incorrect or incomplete for high-wire-number, massive (>2 mg/cm) , single, tungsten wire arrays. In contrast to earlier work where the wire array accelerated from its initial position at approximately 80% of the stagnation time, our results show that very late acceleration is not a universal aspect of wire array implosions. We also varied the ablation period between 46%+/-2% and 71%+/-3% of the stagnation time, for the first time, by scaling the array diameter between 40 mm (at a wire-wire gap of 524 mum ) and 12 mm (at a wire-wire gap of 209 microm ), at a constant stagnation time of 100+/-6 ns . The deviation of the wire-array trajectory from that of a thin shell scales inversely with the ablation rate per unit mass: f(m) proportional[dm(ablate)/dt]/m(array). The convergence ratio of the effective position of the current at peak x-ray power is approximately 3.6+/-0.6:1 , much less than the > or = 10:1 typically inferred from x-ray pinhole camera measurements of the brightest emitting regions on axis, at peak x-ray power. The trailing mass at the array edge early in the implosion appears to produce wings on the pinch mass profile at stagnation that reduces the rate of compression of the pinch. The observation of precursor pinch formation, trailing mass, and trailing current indicates that all the mass and current do not assemble simultaneously on axis. Precursor and trailing implosions appear to impact the efficiency of the conversion of current (driver energy) to x rays. An instability with the character of an m = 0 sausage grows rapidly on axis at stagnation, during the rise time of pinch power. Just after peak power, a mild m = 1 kink instability of the pinch occurs which is correlated with the higher compression ratio of the pinch after peak power and the decrease of the power pulse. Understanding these three-dimensional, discrete-wire implosion characteristics is critical in order to efficiently scale wire arrays to higher currents and powers for fusion applications.

Twenty sexually abused girls, ages 7 to 15 years, received 6 sessions of psychoeducationally based individual counseling from either male (n = 10) or female (n = 10) counselors. Clients' pretreatment and posttreatment preference for sex of their counselor and the girls' anticipated comfort with male versus female counselors were analyzed, as was clients' posttreatment actual comfort with their counselors. Analyses of covariance, with pretreatment data as the covariate, revealed that participants treated by male counselors expressed significantly greater preference for and anticipated comfort with male counselors following completion of the treatment program than did their counterparts who were treated by female counselors. Girls treated by male counselors were not significantly more or less comfortable with their assigned counselor following completion of treatment than were those treated by female counselors.

Rey (1964) proposed a brief screening test to assess the validity of memory complaints and hypothesized that the ease of the task would mislead malingerers to perform more poorly even than persons with impaired memory due to brain injury. Lezak (1983) suggested cut‐offs, but only one empirical report on Rey's task could be located in the literature. That study by Goldberg and Miller (1986) supported Lezak's cut‐offs; however, the criterion groups were psychiatric and mentally retarded inpatients. In the present study, Rey's test, along with other neuropsychological tests designed to determine various types of memory dysfunction, was administered to brain‐damaged (n = 18) and comparison (n = 16) groups. The results again generally supported Lezak's cut‐offs.

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