(Physical Review Letters, 2022-05-11) Bose, A.; Peebles, J.; Walsh, C. A.; Frenje, J. A.; Kabadi, N. V.; Adrian, P. J.; Sutcliffe, G. D.; Johnson, M. Gatu; Frank, C. A.; Davies, J. R.; Betti, R.; Glebov, V. Yu.; Marshall, F. J.; Regan, S. P.; Stoeckl, C.; Campbell, E. M.; Sio, H.; Moody, J.; Crilly, A.; Appelbe, B. D.; Chittenden, J. P.; Atzeni, S.; Barbato, F.; Forte, A.; Li, C. K.; Seguin, F. H.; Petrasso, R. D.
This Letter presents the first observation on how a strong, 500 kG, externally applied B field increases the mode-two asymmetry in shock-heated inertial fusion implosions. Using a direct-drive implosion with polar illumination and imposed field, we observed that magnetization produces a significant increase in the implosion oblateness (a 2.5× larger P2 amplitude in x-ray self-emission images) compared with reference experiments with identical drive but with no field applied. The implosions produce strongly magnetized electrons (ωeτe≫1) and ions (ωiτi>1) that, as shown using simulations, restrict the cross field heat flow necessary for lateral distribution of the laser and shock heating from the implosion pole to the waist, causing the enhanced mode-two shape.
