Using nuclear data and Monte Carlo techniques to study areal density and mix in D{sub 2} implosions

Journal Article · Tue Mar 01 04:00:00 EST 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.1771656· OSTI ID:20698382

Kurebayashi, S; Frenje, J A; Seguin, F H; Rygg, J R; Li, C K; Petrasso, R D; Glebov, V Yu; Delettrez, J A; Sangster, T C; Meyerhofer, D D; Stoeckl, C; Soures, J M; Amendt, P A; Hatchett, S P; Turner, R E ^[1]

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1. Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

Measurements from three classes of direct-drive implosions at the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] were combined with Monte Carlo simulations to investigate models for determining hot-fuel areal density ({rho}R{sub hot}) in compressed, D{sub 2}-filled capsules, and to assess the impact of mix and other factors on the determination of {rho}R{sub hot}. The results of the Monte Carlo simulations were compared to predictions of simple, commonly used models that use ratios of either secondary D{sup 3}He proton yields or secondary DT neutron yields to primary DD neutron yields to provide estimates {rho}R{sub hot,2p} or {rho}R{sub hot,2n}, respectively, for {rho}R{sub hot}. For the first class of implosion, where {rho}R{sub hot} is low ({<=}3 mg/cm2), {rho}R{sub hot,2p} and {rho}R{sub hot,2n} often agree with each other and are often good estimates of the actual {rho}R{sub hot}. For the second class of implosion, where {rho}R{sub hot} is of order 10 mg/cm2, {rho}R{sub hot,2p} often underestimates the actual value due to secondary proton yield saturation; in addition, fuel-shell mix causes {rho}R{sub hot,2p} to further underestimate, and {rho}R{sub hot,2n} to overestimate, {rho}R{sub hot}. As a result, values of {rho}R{sub hot,2p} and {rho}R{sub hot,2n} can be interpreted as lower and upper limits, respectively. For the third class of implosion, involving cryogenic capsules, secondary protons and neutrons are produced mainly in the hot and cold fuel regions, respectively, and the effects of the mixing of hot and cold fuel must be taken into account when interpreting the values of {rho}R{sub hot,2p} and {rho}R{sub hot,2n}. From these data sets, it is concluded that accurate inference of {rho}R{sub hot} requires comprehensive measurements and detailed modeling.

• OSTI ID: 20698382
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 3 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPUTERIZED SIMULATION
DEUTERIUM
FUSION YIELD
LASER IMPLOSIONS
MONTE CARLO METHOD
NEUTRONS
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA SIMULATION
PROTONS