Time-resolved X-ray spectroscopy of deeply buried tracer layers as a density and temperature diagnostic for the fast ignitor

被引:12
作者
Koch, JA [1 ]
Back, CA [1 ]
Brown, C [1 ]
Estabrook, K [1 ]
Hammel, BA [1 ]
Hatchett, SP [1 ]
Key, MH [1 ]
Kilkenny, JD [1 ]
Landen, OL [1 ]
Lee, RW [1 ]
Moody, JD [1 ]
Offenberger, AA [1 ]
Pennington, D [1 ]
Ferry, MD [1 ]
Tabak, M [1 ]
Yanovsky, V [1 ]
Wallace, RJ [1 ]
Wharton, KB [1 ]
Wilks, SC [1 ]
机构
[1] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA
关键词
D O I
10.1017/S0263034600011873
中图分类号
O59 [应用物理学];
学科分类号
摘要
The fast ignitor concept for inertial confinement fusion relies on the generation of hot electrons, produced by a short-pulse ultrahigh intensity laser, which propagate through high-density plasma to deposit their energy in the compressed fuel core and heat it to ignition. In preliminary experiments designed to investigate deep heating of high-density matter, we used a 20 joule, 0.5-30 ps laser to heat solid targets, and used emission spectroscopy to measure plasma temperatures and densities achieved at large depths (2-20 microns) away from the initial target surface. The targets consisted of an Al tracer layer buried within a massive CH slab; H-like and He-like line emission was then used to diagnose plasma conditions. We observe spectra from tracer layers buried up to 20 microns deep, measure emission durations of up to 200 ps, measure plasma temperatures up to T-e = 650 eV, and measure electron densities above 10(23) cm(-3). Analysis is in progress, but the data are in reasonable agreement with heating simulations when space-charge induced inhibition is included in hot-electron transport, and this supports the conclusion that the deep heating is initiated by hot electrons.
引用
收藏
页码:225 / 232
页数:8
相关论文
共 31 条
[1]  
BEG FN, 1998, IN PRESS PHYS PLASMA
[2]  
BELL AR, 1998, IN PRESS PLASMA PHYS
[3]   Relativistic channeling of a picosecond laser pulse in a near-critical preformed plasma [J].
Borghesi, M ;
MacKinnon, AJ ;
Barringer, L ;
Gaillard, R ;
Gizzi, LA ;
Meyer, C ;
Willi, O ;
Pukhov, A ;
MeyerterVehn, J .
PHYSICAL REVIEW LETTERS, 1997, 78 (05) :879-882
[4]   OBSERVATION OF RELATIVISTIC AND CHARGE-DISPLACEMENT SELF-CHANNELING OF INTENSE SUBPICOSECOND ULTRAVIOLET (248 NM) RADIATION IN PLASMAS [J].
BORISOV, AB ;
BOROVSKIY, AV ;
KOROBKIN, VV ;
PROKHOROV, AM ;
SHIRYAEV, OB ;
SHI, XM ;
LUK, TS ;
MCPHERSON, A ;
SOLEM, JC ;
BOYER, K ;
RHODES, CK .
PHYSICAL REVIEW LETTERS, 1992, 68 (15) :2309-2312
[5]   Interaction physics of the fast ignitor concept [J].
Deutsch, C ;
Furukawa, H ;
Mima, K ;
Murakami, M ;
Nishihara, K .
PHYSICAL REVIEW LETTERS, 1996, 77 (12) :2483-2486
[6]   Supersonic ionization wave driven by radiation transport in a short-pulse laser-produced plasma [J].
Ditmire, T ;
Gumbrell, ET ;
Smith, RA ;
Mountford, L ;
Hutchinson, MHR .
PHYSICAL REVIEW LETTERS, 1996, 77 (03) :498-501
[7]   Short-pulse laser-plasma interactions [J].
Gibbon, P ;
Forster, E .
PLASMA PHYSICS AND CONTROLLED FUSION, 1996, 38 (06) :769-793
[8]   Electron temperature measurements of solid density plasmas produced by intense ultrashort laser pulses [J].
Guethlein, G ;
Foord, ME ;
Price, D .
PHYSICAL REVIEW LETTERS, 1996, 77 (06) :1055-1058
[9]   MEASUREMENT OF FAST-ELECTRON ENERGY-SPECTRA AND PREHEATING IN LASER-IRRADIATED TARGETS [J].
HARES, JD ;
KILKENNY, JD ;
KEY, MH ;
LUNNEY, JG .
PHYSICAL REVIEW LETTERS, 1979, 42 (18) :1216-1219
[10]  
Henke B. L., 1993, ATOMIC DATA NUCL TAB, V54