NASA Scientific and Technical Aerospace Reports

20040071087 Brookhaven National Lab., Upton, NY, USA
RCRC Scientific Review Committee Meeting
Samios, N. P.; Lee, T. D.; Nov. 2003; 270 pp.; In English
Report No.(s): DE2004-15006731; BNL-71899-2003; No Copyright; Avail: Department of Energy Information Bridge
The sixth evaluation of the RIKEN BNL Research Center (RBRC) took place on November 20-21, 2003, at Brookhaven
National Laboratory. The present members of the Scientific Review Committee are Dr. Jean-Paul Blaizot, Professor Makoto
Kobayashi, Dr. Akira Masaike, Professor Charles Young Prescott (absent), Professor Stephen Sharpe, and Professor Jack
Sandweiss, Committee Chair. In order to illustrate the breadth and scope of the program, each member of the Center made
a presentation on his research efforts. In addition, a special presentation was given jointly by our collaborators, Professors
Norman Christ and Robert Mawhinney of Columbia University, on the progress and status of the IRBRC QCDSP/QCDOC
Supercomputer program. A demonstration of a 64-node (64 Gflops peak speed) QCDOC machine in action followed. Although
the main purpose of this review is a report to RIKEN Management (Dr. Ryoji Noyori, RIKEN President) on the health,
scientific value, management and future prospects of the Center, the RBRC management felt that a compendium of the
scientific presentations are of sufficient quality and interest that they warrant a wider distribution. Therefore we have made
this compilation and present it to the community for its information and enlightenment.
NTIS
Research and Development; Conferences; Project Management
20040071091 Helsinki Univ. of Technology, Espoo, Finland
Island Growth and Step Instabilities on Flat and Vicinal Surfaces
Rusanen, M.; 2003; 74 pp.; In English
Report No.(s): PB2004-105763; DISSERTATION-120; No Copyright; Avail: CASI; A04, Hardcopy
Surface physics aims at understanding the basic atomistic processes and mechanisms responsible for the variety of
observed structures during surface growth. In addition, surface growth has important consequences in modern technological
applications. Molecular beam epitaxy (MBE) is an established method to grow surface structures, admitting also modeling
surface growth through simple microscopic processes such as dilusion and deposition of atoms. The rather limited parameter
range in MBE where smooth layer by layer growth is realized can be extended, e.g., with ion assisted deposition techniques.
Thus new microscopic processes are added to traditional MBE growth. Customarily island growth and step-ow are treated as
separate growth modes. Consequently, there does not exist a growth model which includes all relevant aspects of surface
growth in a realistic way. The aim of this thesis is to bridge the gap between these traditional approaches.
NTIS
Flat Surfaces; Molecular Beam Epitaxy; Stability; Finland
20040071098 Lawrence Livermore National Lab., Livermore, CA
Surface Damage Growth Mitigation on KDP/DKDP Optics Using Single-Crystal Diamond Micro-Machining
Hrubesh, L.; Adams, J.; Feit, M.; Sell, W.; Stanley, J.; Nov. 12, 2003; In English
Report No.(s): DE2004-15005752; UCRL-CONF-153480; No Copyright; Avail: National Technical Information Service
(NTIS)
A process whereby laser-initiated surface damage on KDP/DKDP optics is removed by spot micro-machining using a
high-speed drill and a single-crystal diamond bit, is shown to mitigate damage growth for subsequent laser shots. Our tests
show that machined dimples on both surfaces of an AR coated doubler (KDP) crystal are stable, for 526nm, (approx.) 3.2ns
pulses at (approx.) 12J/cm(sup 2) fluences. Other tests also confirmed that the machined dimples on both surfaces of an AR
coated tripler (DKDP) crystal are stable, for 351nm, (approx.) 3ns pulses at (approx.) 8J/cm(sup 2). We have demonstrated
successful mitigation of laser-initiated surface damage sites as large as 0.14mm diameter on DKDP, for up to 1000 shots at
351nm, 13J/cm(sup 2), (approx.) 11ns pulse length, and up to 10 shots at 351nm, 8J/cm(sup 2), 3ns. Details of the method
are presented, including estimates for the heat generated during micro-machining and a plan to implement this method to treat
pre-initiated or retrieved-from-service, large-scale optics for use in high-peak-power laser applications.
NTIS
Diamonds; Laser Damage
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