The physics goals for the PEP-4/PEP-9 experiment concentrate on two areas: the fragmentation properties of quarks and gluons produced in e+e- annihilation, and the investigation of hadron production in 2-photon collisions. Only the first of these topics is addressed. Despite the many successes of QCD in the description of deep inelastic reactions, the basic fragmentation process of quarks and gluons is not very well understood. This lack of knowledge has been shown to jeopardize precise test of QCD, such as the accurate determination of the strong coupling constant. With its ability to disentangle complex hadronic events and to identify most of the final state particles, the TPC allows new and more sensitive tests of fragmentation models. A brief description of the detector is given and particle identification by ionization energy loss is described. Next, the inclusive production of stable hadrons and of resonances is discussed, and limits on the inclusive production of fractional charged particles are given. A new analysis of long-range correlations in e+e- annihilation is given.

The BBC CQK 200-4 Tube was tested by Aydin at LLL, to confirm that it would switch 90 kV after conducting 88 amperes for 30 seconds. The CQK 200-4 is a recent modification of the CQK 200-3, an Rf transmitter tube designed for continuous loading, to increase the anode hold-off voltage to 150 kV. During the design life of the tube it will be subjected to 10/sup 5/ to 10/sup 6/ cyclic thermal loads. Two concerns are that (1) during the 30 second high current load, the screen grid may have excessive dissipation causing a loss of control of the tube, and (2) the cyclic temperature-induced stresses in the anode may cause fatigue failures that will reduce the tube's useful life. The first concern was addressed by performing full scale tests at the LLL test facility.

A study was made to estimate the impact tax credits (from Acts passed by Congress) would have on renewable energy investment and to estimate the net costs to the US Treasury of providing these tax credits. The appendices to this study are presented. Some investment and marketing penetration worksheets are presented on wind turbines, solar ponds, flat plates, evacuated tubes, and parabolic troughs. A market penetration and economic analysis program with test written for TI-59 programmable calculator with printer is presented. Data on the average $/kWh for each state are included for energy use (70 to 400/sup 0/F and electricity) and energy resource (total and direct solar and wind). Also included is an energy use processing program written for TI-59 programmable calculator with printer. (MCW)

We describe a technique for atomic density measurements. We generate and recombine frequency shifted laser beams producing beat signals on reference and signal detectors. Opacity in the signal detector leg is proportional to the phase difference between detector signals. 4 refs., 2 figs.

The Supervisory Control and Diagnostics System (SCDS) for the Mirror Fusion Test Facility (MFTF) is a multiprocessor minicomputer system designed so that for most single-point failures, the hardware may be quickly reconfigured to provide continued operation of the experiment. The system is made up of nine Perkin-Elmer computers - a mixture of 8/32's and 7/32's. Each computer has ports on a shared memory system consisting of two independent shared memory modules. Each processor can signal other processors through hardware external to the shared memory. The system communicates with the Local Control and Instrumentation System, which consists of approximately 65 microprocessors. Each of the six system processors has facilities for communicating with a group of microprocessors; the groups consist of from four to 24 microprocessors. There are hardware switches so that if an SCDS processor communicating with a group of microprocessors fails, another SCDS processor takes over the communication.

The Plasma Streaming System (PSS) is an essential portion of the Mirror Fusion Test Facility (MFTF), scheduled for completion in October 1981. The PSS will develop a plasma density of at least 2 x 10/sup 12/ particles/cm/sup 3/ at the MFTF magnet centerline by injecting particles along the field lines. The plasma will have a midplane plasma radius as large as 40 cm with variable plasma particle energy and beam geometry. Minimum amounts of impurities will be injected, with emphasis on minimizing high Z materials. Each of the 60 PSS units will consist of a gun magnet assembly (GMA) and a power supply. Each GMA consists of a plasma streaming gun, a pulse magnet that provides variable beam shaping, and a fast reaction pulse gas valve.

The power supply system for MFTF will consist of twenty-four sets of accel, arc, and filament power supplies. The system will be fed from a common source and split into sets of two for the accel supplies and sets of four for the arc and filament supplies. This paper describes the simulation of this system and the EMTP code that was used. Interactions between power supplies during turn on that are due to common system impedances are studied, and a description of Transient Analysis of Control Systems (TACS) control is presented. The system harmonic content found by EMTP is discussed. The paper concludes with a brief discussion of an accel crowbar simulation.

This paper contains viewgraphs on the existence of currents in ATF Torsatron. Current sources like bootstrap, Pfirsch-Schluter, beam driven and flux conserving are investigated and suggestions on minimization are given. (LSP)

The Mirror Fusion Test Facility, scheduled for completion in October 1981, will contain a complex, state-of-the-art array of electrical and electronics equipment valued at over 60 M$. Three injector systems will be employed to initiate and sustain the MFTF deuterium plasma. A plasma streaming system and a startup neutron beam system will be used to establish a target plasma. A sustaining neutral beam system will be used to fuel and sustain the MFTF plasma for 0.5 s. Additional power supply systems required on MFTF include two magnet power supplies with quench protection circuitry for powering the superconducting YIN/YANG magnet pair and eight 10 KHz power supplies for powering the Ti gettering system. Due to the complexity, physical size, and multiple systems of MFTF, a distributed, hierarchial, computer control and instrumentation system will be used. Color graphic, touch-panel, control consoles will provide the man-machine interface. The MFTF will have the capability of conducting an experiment every five minutes.

The Mirror Fusion Test Facility (MFTF) at the Lawrence Livermore Laboratory (LLL) is currently the largest mirror fusion research project in the world. Its Control and Diagnostics System is handled by a distributed computer network consisting of nine Interdata minicomputer systems and about 65 microprocessors. One of the design requirements is tolerance of single-point failure. If one of the computer systems becomes inoperative, the experiment can still be carried out, although the system responsiveness to operator command may be degraded. In a normal experiment cycle, the researcher can examine the result of the previous experiment, change any control parameter, fire a shot, collect four million bytes of diagnostics data, perform intershot analysis, and have the result presented - all within five minutes. The software approach adopted for the Supervisory Control and Diagnostics System features chief programmer teams and structured programming. Pascal is the standard programming language in this project.

Results based on calorimetric measurements are presented from reactions of 60 A GeV and 200 A GeV /sup 16/O projectiles with C, Cu, Ag, and Au nuclei. Minimum-bias cross sections are discussed. Energy spectra measured at zero degrees and transverse-energy distributions for the pseudorapidity range 2.4 less than or equal to eta less than or equal to 5.5 are shown. An analysis of the average transverse energy in terms of the number of participating nucleons and the number of binary nucleon-nucleon collision is presented. Estimates of nuclear stopping and of attained energy densities are made. 22 refs., 6 figs., 3 tabs.

The design and implementation of the SCDS is a relatively complex problem involving a nine-computer network coupled with a unique color graphics control console system, 50 local control minicomputers, and the usual array of drives, printers, magnetic tapes, etc. Four million bytes of data are to be collected on each MFTF cycle with a repetition rate of five minutes per shot, and the associated data processing and storing load is a major concern. Crude paper studies were made initially to try to size the various components of the system and various configurations were proposed and analyzed prior to the solicitation for the computer system. However, once the hardware was purchased and a preliminary software design was completed, it became essential and feasible to do an analysis of the system to considerably greater depth in order to identify bottlenecks and other system problems and to verify those parts of the design that met the MFTF requirements.

In the design of large experimental control systems, a major concern is ensuring that operators are quickly alerted to emergency or other exceptional conditions and that they are provided with sufficient information to respond adequately. This paper describes how the MFTF exception handling system satisfies these requirements. Conceptually exceptions are divided into one of two classes. Those which affect command status by producing an abort or suspend condition and those which fall into a softer notification category of report only or operator acknowledgement requirement. Additionally, an operator may choose to accept an exception condition as operational, or turn off monitoring for sensors determined to be malfunctioning. Control panels and displays used in operator response to exceptions are described.

The Mirror Fusion Test Facility (MFTF) currently under construction at the Lawrence Livermore Laboratory includes a Sustaining Neutral Beam Power Supply System (SNBPSS) consisting of 24 power-supply sets. The System will operate in long pulses (initially .5 seconds and eventually 30 seconds) at high power (200 MW), which will necessitate a large source of ac power. To meet this requirement, a new 230-kV substation is also being built at LLL. The constraints of cost, equipment protection, short operating lifetime (10 years), and reliability dictated a unique substation design. Its unusual features include provisions for fast fault detection and tripping, a capability for limiting ground fault current, low impedance, and economical design.

The initial goal of the Data Acquisition System (DAS) is to control 11 instruments chosen as the startup diagnostic set and to collect, process, and display the data that these instruments produce. These instruments are described in a paper by Stan Thomas, et. al. entitled ''MFTF Plasma Diagnostics System.'' The DAS must be modular and flexible enough to allow upgrades in the quantity of data taken by an instrument, and also to allow new instruments to be added to the system. This is particularly necessary to support a research project where needs and requirements may change rapidly as a result of experimental findings. Typically, the startup configuration of the diagnostic instruments will contain only a fraction of the planned detectors, and produce approximately one half the data that the expanded version is designed to generate. Expansion of the system will occur in fiscal year 1982.

The relationship between charge transport and mechanical properties of alkanethiol self-assembled monolayers (SAM) on Au(111) films has been investigated using an atomic force microscope with a conductive tip. Molecular tilts induced by the pressure applied by the tip cause stepwise increases in film conductivity. A decay constant {beta} = 0.57 {+-} 0.03 {angstrom}{sup -1} was found for the current passing through the film as a function of tip-substrate separation due to this molecular tilt. This is significantly smaller than the value of {approx} 1 {angstrom}{sup -1} found when the separation is changed by changing the length of the alkanethiol molecules. Calculations indicate that for isolated dithiol molecules S-bonded to hollow sites, the junction conductance does not vary significantly as a function of molecular tilt. The impact of S-Au bonding on SAM conductance is discussed.

Dynamic mechanical analysis has been used to characterize the effects of tritium gas (initially 1 atm. pressure, ambient temperature) exposure over times up to 2.3 years on several thermoplastics-ultrahigh molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE), and Vespel{reg_sign} polyimide, and on several formulations of elastomers based on ethylene propylene diene monomer (EPDM). Tritium exposure stiffened the elastic modulus of UHMW-PE up to about 1 year and then softened it, and reduced the viscous response monotonically with time. PTFE initially stiffened, however the samples became too weak to handle after nine months exposure. The dynamic properties of Vespel{reg_sign} were not affected. The glass transition temperature of the EPDM formulations increased approximately 4 C. following three months tritium exposure.

Gas centrifuges exhibit very complex flows. Within the centrifuge there is a rarefied region, a transition region, and a region with an extreme density gradient. The flow moves at hypersonic speeds and shock waves are present. However, the flow is subsonic in the axisymmetric plane. The analysis may be simplified by treating the flow as a perturbation of wheel flow. Wheel flow implies that the fluid is moving as a solid body. With the very large pressure gradient, the majority of the fluid is located very close to the rotor wall and moves at an azimuthal velocity proportional to its distance from the rotor wall; there is no slipping in the azimuthal plane. The fluid can be modeled as incompressible and subsonic in the axisymmetric plane. By treating the centrifuge as long, end effects can be appropriately modeled without performing a detailed boundary layer analysis. Onsager's pancake approximation is used to construct a simulation to model fluid flow in a gas centrifuge. The governing 6th order partial differential equation is broken down into an equivalent coupled system of three equations and then solved numerically. In addition to a discussion on the baseline solution, known problems and future work possibilities are …

The path towards realizing peta-scale computing isincreasingly dependent on building supercomputers with unprecedentednumbers of processors. To prevent the interconnect from dominating theoverall cost of these ultra-scale systems, there is a critical need forhigh-performance network solutions whose costs scale linearly with systemsize. This work makes several unique contributions towards attaining thatgoal. First, we conduct one of the broadest studies to date of high-endapplication communication requirements, whose computational methodsinclude: finite-difference, lattice-bolzmann, particle in cell, sparselinear algebra, particle mesh ewald, and FFT-based solvers. Toefficiently collect this data, we use the IPM (Integrated PerformanceMonitoring) profiling layer to gather detailed messaging statistics withminimal impact to code performance. Using the derived communicationcharacterizations, we next present fit-trees interconnects, a novelapproach for designing network infrastructure at a fraction of thecomponent cost of traditional fat-tree solutions. Finally, we propose theHybrid Flexibly Assignable Switch Topology (HFAST) infrastructure, whichuses both passive (circuit) and active (packet) commodity switchcomponents to dynamically reconfigure interconnects to suit thetopological requirements of scientific applications. Overall ourexploration leads to a promising directions for practically addressingthe interconnect requirements of future peta-scale systems.

A CLIC designed 18 cells, low group velocity (2.4% to 1.0% c), X-band (11.4 GHz) accelerator structure (denoted T18) was designed at CERN, its cells were built at KEK, and it was assembled and tested at SLAC. An interesting feature of this structure is that the gradient in the last cell is about 50% higher than that in the first cell. This structure has been RF conditioned at SLAC NLCTA for about 1400 hours where it incurred about 2200 breakdowns. This paper presents the characteristics of these breakdowns, including (1) the breakdown rate dependence on gradient, pulse width and conditioning time, (2) the breakdown distribution along the structure, (3) relation between breakdown and pulsed heating dependence study and (4) electric field decay time for breakdown changing over the whole conditioning time. Overall, this structure performed very well, having a final breakdown rate of less than 1e-6/pulse/m at 106 MV/m with 230 ns pulse width.

A 5-cell, normal-conducting, 1.3 GHz, standing-wave (SW) cavity was built as a prototype capture accelerator for the ILC positron source. Although the ILC uses predominantly superconducting cavities, the capture cavity location in both a high radiation environment and a solenoidal magnetic field requires it to be normal conducting. With the relatively high duty ILC beam pulses (1 msec at 5 Hz) and the high gradient required for efficient positron capture (15 MV/m), achieving adequate cavity cooling to prevent significant detuning is challenging. This paper presents the operational performance of this cavity including the processing history, characteristics of the breakdown events and the acceleration gradient witnessed by a single bunch at different injection times for different rf pulse lengths.

A search for lepton flavor violating decays of a {tau} to a lighter-mass charged lepton and an {omega} vector meson is performed using 384.1 fb{sup -1} of e{sup +}e{sup -} annihilation data collected with the BABAR detector at the Stanford Linear Accelerator Center PEP-II storage ring. No signal is found, and the upper limits on the branching ratios are determined to be {beta}({tau}{sup {+-}} {yields} e{sup {+-}}{omega}) < 1.1 x 10{sup -7} and {beta}({tau}{sup {+-}} {yields} {mu}{sup {+-}}{omega}) < 1.0 x 10{sup -7} at 90% confidence level.

This report discusses a general approach to validating microbial forensic methods that attempt to simultaneously distinguish among many hypotheses concerning the manufacture of a questioned biological agent sample. It focuses on the concrete example of determining growth medium from chemical or molecular properties of a bacterial agent to illustrate the concepts involved.

The case of {gamma}-ray absorption due to photon-photon pair production of jet photons in the external photon environments, such as the accretion disk and the broad-line region radiation fields, of {gamma}-ray--loud active galactic nuclei (AGNs) that exhibit strong emission lines is considered. I demonstrate that this 'local opacity,' if detected, will almost unavoidably be redshift-dependent in the sub-TeV range. This introduces nonnegligible biases and complicates approaches for studying the evolution of the extragalactic background light with contemporary GeV instruments such as the Gamma-Ray Large Area Space Telescope (GLAST ), where the {gamma}-ray horizon is probed by means of statistical analysis of absorption features (e.g., the Fazio-Stecker relation) in AGN spectra at various redshifts. It particularly applies to strong-line quasars, where external photon fields are potentially involved in {gamma}-ray production.