SBS pulse compression for excimer inertial fusion energy drivers
- TRW Space and Electronics Group, Redondo Beach, CA (United States). Space and Technology Div.
A key requirement for the development of commercial fusion power plants utilizing inertial confinement fusion (ICF) as a source of thermonuclear power is the availability of reliable, efficient laser drivers. These laser drivers must be capable of delivering UV optical pulses having energies of the order of 5MJ to cryogenic deuterium-tritium (D/T) ICF targets. The current requirements for laser ICF target irradiation specify the laser wavelength, {lambda} ca. 250 nm, pulse duration, {tau}{sub p} ca. 6 ns, bandwidth, {Delta}{lambda} ca. 0.1 nm, polarization state, etc. Excimer lasers are a leading candidate to fill these demanding ICF driver requirements. However, since excimer lasers are not storage lasers, the excimer laser pulse duration, {tau}{sub pp}, is determined primarily by the length of the excitation pulse delivered to the excimer laser amplifier. Pulsed power associated with efficiently generating excimer laser pulses has a time constant, {tau}{sub pp} which falls in the range, 30 {tau}{sub p}<{tau}{sub pp}<100{tau}{sub p}. As a consequence, pulse compression is needed to convert the long excimer laser pulses to pulses of duration {tau}{sub p}. These main ICF driver pulses require, in addition, longer, lower power precursor pulses delivered to the ICF target before the arrival of the main pulse. Although both linear and non-linear optical (NLO) pulse compression techniques have been developed, computer simulations have shown that a ``chirped,`` self-seeded, stimulated Brillouin scattering (SBS) pulse compressor cell using SF{sub 6} at a density, {rho} ca. 1 amagat can efficiently compress krypton fluoride (KrF) laser pulses at {lambda}=248 nm. In order to avoid the generation of output pulses substantially shorter than {tau}{sub p}, the optical power in the chirped input SBS ``seed`` beams was ramped. Compressed pulse conversion efficiencies of up to 68% were calculated for output pulse durations of {tau}{sub p} ca. ns.
- DOE Contract Number:
- AC02-90ER54101
- OSTI ID:
- 55454
- Report Number(s):
- CONF-940142-; ISBN 0-8194-1410-7; TRN: 95:012809
- Resource Relation:
- Conference: OE/LASE `94: conference on optics, electro-optics, and laser applications in science and engineering, Los Angeles, CA (United States), 22-29 Jan 1994; Other Information: PBD: 1994; Related Information: Is Part Of Modeling and simulation of laser systems III. SPIE Volume 2117; Schnurr, A.D. [ed.]; PB: 231 p.
- Country of Publication:
- United States
- Language:
- English
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