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Measurements of ions within an electron capture detector (ECD) have been made by the technique of atmospheric pressure ionization mass spectrometry (APIMS) where the ion source has been modified to be an actual ECD. By observing the dependence of ion signals on electrostatic fields applied to the ionization cell, new insight into the role of ions in influencing the measured ECD current is provided. I t is shown that for this pulsed ECD, a positive current of significant magnitude exists which is an integral component of the normally measured ECD current, and that it is caused by the selective migration of positive ions to the sampling electrodeduring the period between pulses. The results are discussed relative to opposing views of the ECD, and are shown to strongly support one of these.

Inertial confinement fusion implosions using capsules with two concentric shells separated by a low density region (double shells) are reported which closely follow one dimensional (1D) radiatively driven hydrodynamics simulations. Capsule designs which mitigate Au M-band radiation asymmetries appear to correspond more closely to 1D simulations than targets lacking mitigation of hohlraum drive M-band nonuniformities. One capsule design achieves over 50% of the unperturbed 1D calculated yield at a convergence ratio of 25.5, comparable to that of a double-shell design for an ignition capsule at the National Ignition Facility.

A physical model of the pulsed electron capture detector (ECD) for gas chromatography is described. This model differs from previous models in that the incorporation of electrostatic forces between charged particles is shown to be a dominant force in determining the concentrations and location of charged

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