Barrier Foil Heating Simulations Using LASNEX

摘要

It is necessary to place a barrier foil in front of the X-ray converter target to prevent the backstreaming ions. This research note presents the simulations of foil heating using the latest EOS tables. LASNEX simulations are carried out using both DARHT-I1 and ETA-I1 beam parameters. Results for all the foils studied here, using the DARHT-I1 beam parameters, show that the integrated line density along the axis at the end of the 4th pulse remains essentially unchanged even if the foils are heated by beams with relatively small beam spot sizes. The temperature can reach up to 3000 degree C on graphite foil but can only reach several hundred degree Celsius on Mylar foil. Simulations also show that ETA-I1 beam can create a 'burn-through' hole on all the foils except graphite and diamond foils, which may require pre-heat. The threshold beam spot size required for hole formation will be compared with LASNEX simulation for the purpose of code verification.