Sandia Proposes To Design Accelerator Expected To Achieve High-Yield Fusion

ALBUQUERQUE, N.M. -- Permission to prepare a conceptual design for anaccelerator, X-1, has been formally requested by Sandia National LaboratoriesPresident Paul Robinson in a letter to the Department of Energy (DOE).

If funded, X-1 would be expected to reach initial operating capability by about2007 and high-yield fusion by about 2010 as well as provide important data forthe nation's stockpile stewardship program.

The request was made after Sandia's continually improving Z accelerator -- themost energetic and powerful laboratory producer of X-rays on Earth -- achieved1.8 million degrees Kelvin, passing the fourth and final milestone of 1.7million degrees established by Sandia scientific researchers four years ago, andreviewed by scientific committees during the last two years.

In February, Z had met three of its four milestones, and the fourth was near.The fourth has now been achieved.

Z would serve as a model for the larger X-1 machine. X-1 should produce x-raytemperatures of more than 3 million degrees, which, when combined with enoughx-ray energy and power, should be sufficient to implode fusion capsules ofdeuterium and tritium (isotopes of hydrogen) to achieve high-yield fusion.

High-yield means that considerably more energy is released by a nuclear reactionthan was used to ignite it. The reaction, the same type as occurs in our sun,could eventually be used to produce virtually limitless electrical power. Theachievement also means that basic science experiments involving fusion capsulescan begin on Z, as well as more intensive weapons physics experiments.

The basis for a series of technical breakthroughs initially involved adding morewires to a target the size of a spool of thread. Later, the size of this "wirearray" was reduced, and multiple shells of wires increased the temperature evenfurther. The combination of several individual techniques for improving theuniformity of the x-ray source has resulted in the performance milestones beingdramatically exceeded.

Specific milestones and achievements are:

• Energy, 1.5 megajoules; achieved, 2.0 megajoules.
• Power, 150 terawatts; achieved, 290 terawatts.
• Temperature: weapons physics configurations, 100 eV (1.2 million degreesKelvin); achieved, 140 eV (1.6 million degrees K).
• Temperature in a configuration suitable for target compression (fusion)experiments, 150 eV (1.7 million degrees K); achieved, 155 eV (1.8 milliondegrees K).

The team of researchers, including scientists from Sandia, Los Alamos, andLivermore national laboratories, hope that a DOE meeting to decide on proceedingwith conceptual design of X-1 can be held in August.

(For more information about Z, see a March 2, 1998, news release on Sandia's website: http://www.sandia.gov/media/z290.htm.)

Sandia is a multiprogram DOE laboratory, operated by a subsidiary of LockheedMartin Corp. With main facilities in Albuquerque, N.M., and Livermore, Calif.,Sandia has major research and development responsibilities in national security,energy, and environmental technologies and economic competitivene