The effects of fill tubes on the hydrodynamics of ignition targets and prospects for ignition

Journal Article · Fri Nov 19 04:00:00 EST 2004 · Physics of Plasmas

OSTI ID:950617

Edwards, M J; Marinak, M M; Dittrich, T; Haan, S; Sanchez, J; Klingman, J; Moody, J

The notion of using a narrow bore fill tube to charge an ignition capsule in-situ with DT fuel is very attractive because it eliminates the need for cryogenic transport of the target from the filling station to the target chamber, and in principle is one way of allowing any material to be considered as an ablator. We are using the radiation hydrocode HYDRA in 2D to study the effect of fill-tubes on graded copper doped Be ignition capsule implosions. The capsule is {approx} 1.1 mm radius, and driven at {approx} 300 eV. Fill-tubes are made of glass and range in diameter from 10-20 {micro}m. These are inserted between 5-40 {micro}m into the ablator surface and a glue layer around the capsule {approx} 2 {micro}m thick is included. The calculations are unusually demanding in that the flow is highly nonlinear from the outset, and very high angular resolution is necessary to capture the initial evolution of the tube, which is complex. Despite this complexity, the net result is that by the time the capsule implosion takes off, a preferred, simple Bessel-like mode is set up that is almost independent of, and much larger than, the initial tube size, and close to the fastest growing mode for the capsule. The perturbation continues to grow during the unstable acceleration phase, and inverts as the capsule begins to stagnate, sending a spike of cold DT into the forming hot-spot. In all cases studied the capsule ignites and gives close to clean 1D yield, and the perturbation growth is found to vary linearly with the diameter of the tube. The simulations and results are discussed.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 950617
• Report Number(s): UCRL-JRNL-208222
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATION
COPPER
CRYOGENICS
GASOLINE SERVICE STATIONS
GLASS
HYDRA
HYDRODYNAMICS
IGNITION
IMPLOSIONS
RADIATIONS
RESOLUTION
TARGET CHAMBERS
TARGETS
TRANSPORT