Lawrence Livermore National Laboratory Safeguards and Security quarterly progress report ending March 31, 1996

LLNL carries out safeguards and security activities for DOE Office of Safeguards and Security (OSS) and other organizations within and outside DOE. LLNL is supporting OSS in 6 areas: safeguards technology, safeguards and materials accountability, computer security--distributed systems, complex-wide access control, standardization of security systems, and information technology and security center. This report describes the activities in each of these areas

Progress in the Development of the 1 m Model of the 70 mm Aperture Quadrupole for the LHC Low-β\beta Insertions

Within the LHC magnet development program Oxford Instruments has built a one metre model of the 70 mm aperture low-beta quadrupole. The magnet features a four layer coil wound from two 8.2 mm wide graded NbTi cables, and is designed for 250 T/m at 1.9 K. The magnet has previously been tested between 4.5 K and 2.3 K. In this paper we review the magnet rebuild and the subsequent tests. Results on magnet training at 4.3 K and 1.9 K are presented along with the results related to quench protection studies.

Lawrence Livermore National Laboratory safeguards and security quarterly progress report to the U.S. Department of Energy. Quarter ending September 30, 1996

The paper describes tasks undertaken in each of the following areas: Safeguards technology program (STP); Safeguards and material accountability (SMA); Computer security, distributed systems; Complex-wide access control system (CWAC); and Standardization of security systems (SSS). The STP develops advanced, nondestructive analysis technology for measurement of special nuclear materials. Work focuses on R and D relating to X- and gamma-ray spectrometry and to development of computer codes for interpreting the spectral data obtained by these techniques. The SMA is concerned with four areas: insider protection; material accountability; planning and evaluation; and information security. The Computer Security Technology Center provides expertise and solutions to the many information security problems present in today`s computer systems and networks. Incidents of intrusions, computer viruses, the purposeful replacement of legitimate software for illegal purposes, and similar acts are being addressed by the creation of security software, the delivery of incident response expertise, and research and development into secure systems. The purpose of the CWAC is to develop an approach that will allow visitors to use their DOE standard badge in access control systems throughout the DOE complex. The purpose of the SSS project is to support the standardization of security systems to meet DOE orders and requirements, and to support the DOE in offering relevant security technology and capabilities to Federal standardization efforts

Lawrence Livermore National Laboratory safeguards and security quarterly progress report to the U.S. Department of Energy. Quarter ending September 30, 1996

The paper describes tasks undertaken in each of the following areas: Safeguards technology program (STP); Safeguards and material accountability (SMA); Computer security, distributed systems; Complex-wide access control system (CWAC); and Standardization of security systems (SSS). The STP develops advanced, nondestructive analysis technology for measurement of special nuclear materials. Work focuses on R and D relating to X- and gamma-ray spectrometry and to development of computer codes for interpreting the spectral data obtained by these techniques. The SMA is concerned with four areas: insider protection; material accountability; planning and evaluation; and information security. The Computer Security Technology Center provides expertise and solutions to the many information security problems present in today`s computer systems and networks. Incidents of intrusions, computer viruses, the purposeful replacement of legitimate software for illegal purposes, and similar acts are being addressed by the creation of security software, the delivery of incident response expertise, and research and development into secure systems. The purpose of the CWAC is to develop an approach that will allow visitors to use their DOE standard badge in access control systems throughout the DOE complex. The purpose of the SSS project is to support the standardization of security systems to meet DOE orders and requirements, and to support the DOE in offering relevant security technology and capabilities to Federal standardization efforts

Quench Performance and Field Quality Measurements of the First LHC low-β\beta Quadrupole Model

As part of the LHC magnet development program, CERN in collaboration with Oxford Instruments has designed, built and tested a one metre model of a 70 mm aperture low-beta quadrupole. The magnet features a four layer coil, and is designed for 250 T/m at 1.9 K. We review the results of the magnet training and quench propagation studies performed at 4.3 K and 1.9 K, and report on the magnetic field measurements

Ultrafast Relaxation Dynamics of Hot Optical Phonons in Graphene

Using ultrafast optical pump-probe spectroscopy, we study the relaxation dynamics of hot optical phonons in few-layer and multi-layer graphene films grown by epitaxy on silicon carbide substrates and by chemical vapor deposition on nickel substrates. In the first few hundred femtoseconds after photoexcitation, the hot carriers lose most of their energy to the generation of hot optical phonons which then present the main bottleneck to subsequent carrier cooling. Optical phonon cooling on short time scales is found to be independent of the graphene growth technique, the number of layers, and the type of the substrate. We find average phonon lifetimes in the 2.5-2.55 ps range. We model the relaxation dynamics of the coupled carrier-phonon system with rate equations and find a good agreement between the experimental data and the theory. The extracted optical phonon lifetimes agree very well with the theory based on anharmonic phonon interactions.Comment: 4 pages, 3 figure

Chronic Oedema and the older person: The effects of ageing upon treatment outcomes

Chronic oedema (CO) and lymphoedema (LO) are long-term conditions that can become more complicated or are more likely to develop with age. The ageing process can involve alterations in the structures that support the normal function of the lymphatic system or put it at greater risk of damage. The main three components (skin care, exercise and compression therapy) within the management of CO/LO can become more difficult to apply with age. This is because of reduced healing rates, decreased cardiovascular capacity and deterioration in vascular and arterial structures. The impact of ageing and how this can affect patients and treatment outcomes requires careful consideration

Measurement of the Optical Absorption Spectra of Epitaxial Graphene from Terahertz to Visible

We present experimental results on the optical absorption spectra of epitaxial graphene from the visible to the terahertz (THz) frequency range. In the THz range, the absorption is dominated by intraband processes with a frequency dependence similar to the Drude model. In the near IR range, the absorption is due to interband processes and the measured optical conductivity is close to the theoretical value of $e^{2}/4\hbar$. We extract values for the carrier densities, the number of carbon atom layers, and the intraband scattering times from the measurements