Re-Assessing the Maximum Allowed Infrared (IR) Power for Enchanced Layering in a Conduction Dominated Cryogenic NIF-Scale Hohlraum

Kozioziemski, B J

Lawrence Livermore National Laboratory

关键词: Heating;    Energy Absorption;    70 Plasma Physics And Fusion Technology;    Deuterium;    Infrared Radiation;   

DOI  :  10.2172/15005143
RP-ID  :  UCRL-ID-155175
RP-ID  :  W-7405-ENG-48
RP-ID  :  15005143

美国|英语

来源: UNT Digital Library

【 摘 要 】

Recent measurements of the infrared (IR) absorption coefficient of CH and CD capsules differ significantly from earlier estimated values from thin flat samples. The optimum wavelength for IR enhanced layering of DT and D{sub 2} ice layers inside of a NIF scale hohlraum depends on the relative ice and capsule absorption coefficients. This update of a previous memo shows the maximum ice heating with IR as a function of ice and capsule absorption instead of at discrete wavelengths. Also discussed is the leverage of other parameters, such as the IR absorption of the hohlraum wall and thermal conductivities of the support rods and exchange gas. The most likely capsule and ice absorption values limit the IR heating to between 2-7 Q{sub DT}. We find most leverage of the IR heating comes from increasing the ice to capsule absorption ratio. As before, this is the conduction only limit to IR, with convection potentially playing a large role.