Monoenergetic-proton-radiography measurements of implosion dynamics in direct-drive inertial-confinement fusion

• Published in: Physical review letters Vol. 100; no. 22; p. 225001
• Main Authors: Li, C K, Séguin, F H, Rygg, J R, Frenje, J A, Manuel, M, Petrasso, R D, Betti, R, Delettrez, J, Knauer, J P, Marshall, F, Meyerhofer, D D, Shvarts, D, Smalyuk, V A, Stoeckl, C, Landen, O L, Town, R P J, Back, C A, Kilkenny, J D
• Format: Journal Article
• Language: English
• Published: United States 06.06.2008
• Subjects: Diagnostic Imaging - methods; Protons; Radiography - methods; Spectrum Analysis - methods
• ISSN: 0031-9007
• DOI: 10.1103/physrevlett.100.225001

Time-gated, monoenergetic radiography with 15-MeV protons provides unique measurements of implosion dynamics in direct-drive inertial-confinement fusion. Images obtained during acceleration, coasting, deceleration, and stagnation display a comprehensive picture of spherical implosions. Critical information inferred from such images, hitherto unavailable, characterizes the spatial structure and temporal evolution of self-generated fields and plasma areal density. Results include the first observation of a radial electric field inside the imploding capsule. It is initially directed inward (at approximately 10(9) V/m), eventually reverses direction ( approximately 10(8) V/m), and is the probable consequence of the evolution of the electron pressure gradient.