Limits to Enhanced IR Layering Set by Long Scale Ablator Roughness

Kozioziemski, B J

Lawrence Livermore National Laboratory

关键词: 70 Plasma Physics And Fusion Technology;    Thickness;    Roughness;    Absorption;    Thermal Conduction;   

DOI  :  10.2172/15007264
RP-ID  :  UCRL-TR-155814
RP-ID  :  W-7405-ENG-48
RP-ID  :  15007264

美国|英语

来源: UNT Digital Library

【 摘 要 】

We show that long scale-length ablator roughness sets a limit to the enhanced IR layering power possible in a NIF ignition hohlraum. This limit can be more restrictive than the limit set by thermal conduction. High IR power absorption, characteristic of the ablator material, combined with ablator roughness can produce ice thickness variations which exceed the NIF ice layer roughness specification. For example, if the capsule IR absorption coefficient is greater than 13 cm{sup -1}, the max IR power is less than the 4 Q{sub DT} limit set by thermal conduction.