Simulations of the propagation of multiple-FM smoothing by spectral dispersion on OMEGA EP

Journal Article · Mon Feb 18 00:00:00 EST 2013 · Proceedings of SPIE - The International Society for Optical Engineering

DOI:https://doi.org/10.1117/12.2003209· OSTI ID:1087590

Kelly, J. H. ^[1]; Shvydky, A. ^[2]; Marozas, J. A. ^[2]; Guardalben, M. J. ^[2]; Kruschwitz, B. E. ^[2]; Waxer, L. J. ^[2]; Dorrer, C. ^[2]; Hill, E. ^[2]; Okishev, A. V. ^[2]; Di Nicola, J.-M. ^[3]

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1. Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics; Laboratory for Laser Energetics, University of Rochester, Rochester, NY
2. Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

A one-dimensional (1-D) smoothing by spectral dispersion (SSD) system for smoothing focal-spot nonuniformities using multiple modulation frequencies has been commissioned on one long-pulse beamline of OMEGA EP, the first use of such a system in a high-energy laser. Frequency modulation (FM) to amplitude modulation (AM) conversion in the infrared (IR) output, frequency conversion, and final optics affected the accumulation of B-integral in that beamline. Modeling of this FM-to-AM conversion using the code Miró. was used as input to set the beamline performance limits for picket (short) pulses with multi-FM SSD applied. This article first describes that modeling. The 1-D SSD analytical model of Chuang is first extended to the case of multiple modulators and then used to benchmark Miró simulations. Comparison is also made to an alternative analytic model developed by Hocquet et al. With the confidence engendered by this benchmarking, Miró results for multi-FM SSD applied on OMEGA EP are then presented. The relevant output section(s) of the OMEGA EP Laser System are described. The additional B-integral in OMEGA EP IR components upstream of the frequency converters due to AM is modeled. The importance of locating the image of the SSD dispersion grating at the frequency converters is demonstrated. In conclusion, since frequency conversion is not performed in OMEGA EP’s target chamber, the additional AM due to propagation to the target chamber’s vacuum window is modeled.

• Research Organization: Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: FC52-08NA28302
• OSTI ID: 1087590
• Report Number(s): DOE/NA/28302--1122; 2012-127; 2094
• Journal Information: Proceedings of SPIE - The International Society for Optical Engineering, Journal Name: Proceedings of SPIE - The International Society for Optical Engineering Vol. 8602; ISSN 0277-786X
• Publisher: SPIE
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
B-integral
Miro
SSD
beam conditioning
beam smoothing
dispersion
fusion lasers
polar-drive
simulations