  NIF experiments with Be capsules have followed a path of the highly
successful "high-foot" CH capsules. Several keyhole and ConA targets preceeded
a DT layered shot. In addition to backscatter subtraction, laser drive
multipliers were needed to match observed X-ray drives. Those for the picket
(0.95), trough (1.0) and second pulse (0.80) were determined by VISAR
measurements. The time dependence of the Dante total x-ray flux and its
fraction > 1.8 keV reflect the time dependence of the multipliers. A two step
drive multiplier for the main pulse can match implosion times, but Dante
measurements suggest the drive multiplier must increase late in time. With a
single set of time dependent, multi-level multipliers the Dante data are well
matched. These same third pulse drive multipliers also match the implosion
times and Dante signals for two CH capsule DT. One discrepancy in the
calculations is the X-ray flux in the picket. Calculations over-estimate the
flux > 1.8 keV by a factor of ~100, while getting the total flux correctly.
These harder X-rays cause an expansion of the Be/fuel interface of 2-3 km/s
before the arrival of the first shock. VISAR measurements show only 0.2 to 0.3
km/s. The X-ray drive on the DT Be capsule was further degraded by a random
decrease of 9% in the total picket flux. This small change caused the capsule
fuel to change from an adiabat of 1.8 to 2.3 by mistiming of the first and
second shocks. With this shock tuning and adjustments to the calculation, the
first NIF Be capsule implosion achieved 29% of calculated yield, comparable to
the CH DT capsules of 68% and 21%. Inclusion of a large M1 asymmetry in the DT
ice layer and mixing from instability growth may help explain this final
degradation. In summary when driven similarly the Be capsules performed like CH
capsules. Performance degradation for both seems to be dominated by drive and
capsule asymmetries.

Plasma Physics