San Diego, California, 17-19 June 2002

Target Physics Issues for Z-Pinch-Driven Inertial Fusion Energy

T.A. Mehlhorn¹, S.A. Slutz¹, R.A. Vesey¹, J.E. Bailey¹, G. Bennett², G.A. Chandler¹, M.E. Cuneo¹, M.K. Matzen^1, , T.J. Nash¹, J.L. Porter¹, W. Varnum³

1Sandia National Laboratories

2Ktech CorporationCorporation

3Comforce

Albuquerque, New Mexico, USA

Tamehlhsandia.gov

 

Successful capsule implosions have been performed on the Z accelerator at Sandia National Laboratories. In one series, the implosion of a capsule in a double-z-pinch driven secondary hohlraum [1] was radiographed by 6.7 keV x-rays produced by the Z-Beamlet Laser (ZBL). These experiments demonstrated capsule radiation drive symmetry of about 4%, within 1.7 to 3 times that required to scale to high yield [2]. In one series, the implosion of a capsule in a double-ended hohlraum was backlit by x-rays from the Z-Beamlet Laser (ZBL); these experiments demonstrated a degree of radiation symmetry control in a vacuum hohlraum. In another series, the hot imploded core of a capsule imploded in a dynamic hohlraum was imaged and argon K-shell spectra were obtained [3]; these experiments demonstrated the ability to heat fuel to greater than 1 keV. These successes increase our interest in developing target designslay the foundation for our z-pinch-driven Iinertial Ffusion Eenergy (IFE) target concepts. Additional scaling information on capsule performance will be enabled by the enhanced radiation drive conditions resulting from the refurbishment of Z (called ZR). Furthermore, there is growing excitement surrounding the ongoing work to add a petawatt short pulse capability to ZBL that will enable research into fast ignition physics on the combination of ZR and ZBL-PW. The recyclable transmission (RTL) concept [4] for repetitive z-pinch operation for IFE, however, may require fusion yields of 3-4 GJ for efficient generation of electricity. This requirement presents an interesting challenge to IFE capsule designers to develop efficient (high gain) fusion capsules that also produce very high yields (several gigajoules); present high yield capsule designs have outputs in the 0.5 to 1 GMJ range. This talk will overview In this presentation we will the present discuss the status of z-pinch-driven capsule experiments, the status of ZR and ZBL-PW, and plans for future capsule experiments, including research into fast ignition physics. The status of z-pinch-driven high yield capsule designs and some of the issues that we are beginning to address to develop a self-consistent design for a repetitive z-pinch driver and a high yield IFE capsule will also be presented.

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U. S. Department of Energy under contract no. DE-AC04-94AL85000.

[1] M. E. Cuneo et al., submitted to Phys. Rev. Lett.

[2] G. R. Bennett et al., in preparation for Phys. Rev. Lett.

[3] J. E. Bailey et al., in preparation for Phys. Rev. Lett.

[4] S.A. Slutz, et al, Proceedings-ICENES 2000, Petten, The Netherlands, p 515