title: Monoenergetic-proton-radiography measurements of implosion dynamics in direct-drive inertial-confinement fusion.
abstract: 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.
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: C K
authors.initials: CK
authors.lastname: Li
authors.forename: F H
authors.initials: FH
authors.lastname: Séguin
authors.forename: J R
authors.initials: JR
authors.lastname: Rygg
authors.forename: J A
authors.initials: JA
authors.lastname: Frenje
authors.forename: M
authors.initials: M
authors.lastname: Manuel
authors.forename: R D
authors.initials: RD
authors.lastname: Petrasso
authors.forename: R
authors.initials: R
authors.lastname: Betti
authors.forename: J
authors.initials: J
authors.lastname: Delettrez
authors.forename: J P
authors.initials: JP
authors.lastname: Knauer
authors.forename: F
authors.initials: F
authors.lastname: Marshall
authors.forename: D D
authors.initials: DD
authors.lastname: Meyerhofer
authors.forename: D
authors.initials: D
authors.lastname: Shvarts
authors.forename: V A
authors.initials: VA
authors.lastname: Smalyuk
authors.forename: C
authors.initials: C
authors.lastname: Stoeckl
authors.forename: O L
authors.initials: OL
authors.lastname: Landen
authors.forename: R P J
authors.initials: RP
authors.lastname: Town
authors.forename: C A
authors.initials: CA
authors.lastname: Back
authors.forename: J D
authors.initials: JD
authors.lastname: Kilkenny
mesh_terms: D003952:Diagnostic Imaging / Q000379:methods; D011522:Protons; D011859:Radiography / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D011522:Protons