This article discusses research that has demonstrated the utility of a rigorously calibrated, molecular mechanics/semiempirical quantum mechanical protocol for developing stereoelectronic (Tolman) maps for phosphine ligands.

The 1992-1995 running of the Fermilab Tevatron (the so-called Run 1) ended with many important physics goals accomplished, including the discovery of the top quark, and the anticipation of many further questions be to answered in the future. In March 2002, after many detector upgrades by both the CDF and D0 experiments, and significant upgrades of the accelerator itself, the Tevatron Run 2 began (after a detector commissioning run) with the ultimate goal of discovering the Higgs boson. Here, we will highlight some important Run 1 results from CDF in the areas of top quark and Higgs boson physics, show some preliminary studies from Run 2, and give some expectations of what Run 2 will ultimately provide to our understanding of matter.

Two CMS production Cathode Strip Chambers were tested for aging effects in the high radiation environment at the Gamma Irradiation Facility at CERN. The chambers were irradiated over a large area: in total, about 2.1 m{sup 2} or 700 m of wire in each chamber. The 40% Ar+50%CO{sub 2}+10%CF{sub 4} gas mixture was provided by an open-loop gas system for one of the chambers and by closed-loop recirculating gas system for the other. After accumulating 0.3-0.4 C per centimeter of a wire, which is equivalent to operation during about 30-50 years at the peak LHC luminosity, no significant changes in gas gain, chamber efficiency, and wire signal noise were observed for either of the two chambers. The only consistent signs of aging were a small increase in dark current from {approx}2 nA to {approx}10 nA per plane of 600 wires and a decrease of strip-to-strip resistance from 1000 G{Omega} to 10-100 G{Omega}. Disassembly of the chambers revealed deposits on the cathode planes, while the anode wires remained fairly clean.

We present two new measurements of the top-quark mass. Using the same methodology applied in Run I, the CDF experiment uses 72 pb{sup -1} of Run II data to measure M{sub top} = 171.2 {+-} 13.4{sub stat} {+-} 99{sub syst} GeV/c{sup 2}. On the other hand, the D0 experiment, using 125 pb{sup -1} from Run I, and applying a new method that extracts information from data through a direct calculation of a probability for each event, obtains M{sub top} = 180.1 {+-} 3.6{sub stat} {+-} 4.0{sub syst} GeV/c{sup 2}.

While commodity computing and graphics hardware has increased in capacity and dropped in cost, it is still quite difficult to make effective use of such systems for general-purpose parallel visualization and graphics. We describe the results of a recent project that provides a software infrastructure suitable for general-purpose use by parallel visualization and graphics applications. Our work combines and extends two technologies: Chromium, a stream-oriented framework that implements the OpenGL programming interface; and OpenRM Scene Graph, a pipelined-parallel scene graph interface for graphics data management. Using this combination, we implement a sort-first, distributed memory, parallel volume rendering application. We describe the performance characteristics in terms of bandwidth requirements and highlight key algorithmic considerations needed to implement the sort-first system. We characterize system performance using a distributed memory parallel volume rendering application, a nd present performance gains realized by using scene specific knowledge to accelerate rendering through reduced network bandwidth. The contribution of this work is an exploration of general-purpose, sort-first architecture performance characteristics as applied to distributed memory, commodity hardware, along with a description of the algorithmic support needed to realize parallel, sort-first implementations.

We present measurements on gauge boson production from data taken during 1994-1996 by the D0 and CDF detectors: the differential production cross section of the W boson as a function of the transverse momentum [1,2], the ratio of W and Z differential cross sections [3,4], direct photon cross-sections at {radical}s = 630 and 1800 GeV [5,6], and studies of Drell-Yan production [7,8]. All measurements are in good agreement with currently available theoretical predictions in most of the measured kinematic range.

This note is a write-up of contribution made by the author to the HCP2002 conference. It has two principal subjects. The first subject concerns the CDF {tau} triggers, {tau}-cone algorithms and {tau} physics analysis. {tau} physics is going to be very important in Run II because {tau}'s can extend SUSY searches at large tan {beta} in particular, {tau}'s will help in the searches for {tilde {chi}}{sub 1}{sup {+-}}{tilde {chi}}{sub 2}{sup 0}, MSSM Higgs and other non Standard Model (SM) processes. Also, {tau} events are important for various Standard Model processes including Precision Electroweak, t{bar t}, and SM Higgs searches. {tau} triggers are installed and operating at CDF. The second subject of this contribution to the HCP2002 conference concerns the algorithms of backwards differentiation abstracted from their usual setting inside of Automatic Differentiation software packages. Backwards differentiation (reverse-mode differentiation) provides a useful means for optimizing many kinds of problems.

The SNS Extraction Fast Kicker System is a very high power, high repetition rate pulsed power system. It was design and developed at Brookhaven National Laboratory. This system will consist of fourteen identical high voltage, high current modulators, and their auxiliary control and charging systems. The modulators will drive fourteen extraction magnet sections located inside of the SNS accumulator ring. The required kicker field rise time is 200 ns, a pulse flattop of 700 ns, a pulse repetition rate of 60 pulse-per-second. A 2500 Ampere per modulator output is required to reach the extraction kicker magnetic field strength. This design features a Blumlein Pulse-Forming-Network based topology, a low beam impedance termination, a fast current switching thyratron, and low inductance capacitor banks. It has a maximum charging voltage of 50kV, an open circuit output of 100kV, and a designed maximum pulsed current output of 4kA per modulator. The overall system output will be multiple GVA with 60 Pulse-per-second repetition rate. A prototype modulator has been successfully built and tested well above the SNS requirement. The modulator system production is in progress.

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Run-II at Fermilab is progressing steadily. In the Run-II scheme, 36 antiproton bunches collide with 36 proton bunches at the CDF and D0 interaction regions in the Tevatron at 980 GeV per beam. The current status and performance of the Fermilab Accelerator complex is reviewed. The plan for Run-II, accelerator upgrades and integration of the Recycler in the accelerator chain will be presented.

The Run 2 at Tevatron will define a new level of precision for QCD studies in hadron collisions. Both collider experiments, CDF and D0, expect to collect up to 15 fb{sup -1} of data in this new run period. The increase in instantaneous luminosity, center-of-mass energy (from 1.8 TeV to 2 TeV) and the improved acceptance of the detectors will allow stringent tests of the Standard Model (SM) predictions in extended regions of jet transverse energy, E{sub T}{sup jet}, and jet pseudorapidity, {eta}{sup jet}. In the following, a review of some of the most important QCD results from Run 1 is presented, together with first preliminary Run 2 measurements (based on the very first data collected by the experiment) and future prospects as the integrated luminosity increases.

The authors present the most recent results of searches for physics beyond the Standard Model using the CDF and D detector in the contest of Supersymmetry (SUSY) with Supergravity (SUGRA) constraints. All results described correspond to analysis performed using the past 1992-1996 Fermilab Tevatron Run I data (roughly 110 pb{sup -1} per each experiment). In particular they report on searches for stop decay in tau channel assuming -Paris violation; searches for -Parity Violating LSP decays in di-muon plus 4 jets channel; searches for resonant slepton production in -Paris Violating mSUGRA; searches for mSUGRA in single electron channel assuming -Parity Conservation and searches for stop decay in 3-4 bodies.

In this paper we analyze the propagation of noise in iterative image reconstruction algorithms. We derive theoretical expressions for the general form of preconditioned gradient algorithms with line searches. The results are applicable to a wide range of iterative reconstruction problems, such as emission tomography, transmission tomography, and image restoration. A unique contribution of this paper comparing to our previous work [1] is that the line search is explicitly modeled and we do not use the approximation that the gradient of the objective function is zero. As a result, the error in the estimate of noise at early iterations is significantly reduced.

As part of Fermilab's study of a Very Large Hadron Collider, a water-cooled photon stop was proposed as a device to intercept the synchrotron radiation emitted by the high-energy proton beams in the high field superconducting magnets with minimal plug-cooling power. Photon stops are radiation absorbers operating at room temperature that protrude into the beam tube at the end of each bending magnet to scrape the synchrotron light emitted by the beam one magnet up-stream. Among the technological challenges regarding photon stops is their cryo-design. The photon stop is water-cooled and operates in a cryogenic environment. A careful cryo-design is therefore essential to enable operation at minimum heat transfer between the room temperature sections and the cryogenic parts. A photon stop cryo-design was developed and a prototype was built. This paper presents the results of the cryogenic experiments conducted on the first VLHC photon stop prototype.

The recent development of new prostate tracers has motivated us to build a low cost PET camera optimized to image the prostate. Coincidence imaging of positron emitters is achieved using a pair of external curved detector banks. The bottom bank is fixed below the patient bed, and the top bank moves upward for patient access and downward for maximum sensitivity. In this paper, we study the design of septa for the prostate camera using Monte Carlo simulations. The system performance is measured by the detectability of a prostate lesion. We have studied 17 septa configurations. The results show that the design of septa has a large impact on the lesion detection at a given activity concentration. Significant differences are also observed between the lesion detectability and the conventional noise equivalent count (NEC) performance, indicating that the NEC is not appropriate for the detection task.

A snapshot of the status of the CDF Run II Silicon Detector dated July 2002 is presented, with a summary of commissioning issues since the start of Run II, current performance of the detector, and the use of the data in both the trigger and offline reconstruction.

We present results on rare charm and B decays using 65pb{sup -1} of data taken with the CDF detector in Run II. Three results are discussed, a measurement of the relative branching ratios {Lambda}(D{sup 0} {yields} K{sup +}K{sup -})/{Lambda}(D{sup 0} {yields} K{pi}) and {Lambda}(D{sup 0} {yields} {pi}{sup +}{pi}{sup -})/{Lambda}(D{sup 0} {yields} K{pi}) and the direct CP-violating decay rate asymmetry, and a limit on the branching ratio of the FCNC decay D{sup 0} {yields} {mu}{sup +}{mu}{sup -}. We also discuss the prospects for the search for B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -} decays.

Two biodegradation models are developed to represent natural attenuation of fuel-hydrocarbon contaminants as observed in a comprehensive natural-gradient tracer test in a heterogeneous aquifer on the Columbus Air Force Base in Mississippi. The first, a first-order mass loss model, describes the irreversible losses of BTEX and its individual components, i.e., benzene (B), toluene (T), ethyl benzene (E), and xylene (X). The second, a reactive pathway model, describes sequential degradation pathways for BTEX utilizing multiple electron acceptors, including oxygen, nitrate, iron and sulfate, and via methanogenesis. The heterogeneous aquifer is represented by multiple hydraulic conductivity (K) zones delineated on the basis of numerous flowmeter K measurements. A direct propagation artificial neural network (DPN) is used as an inverse modeling tool to estimate the biodegradation rate constants associated with each of the K zones. In both the mass loss model and the reactive pathway model, the biodegradation rate constants show an increasing trend with the hydraulic conductivity. The finding of correlation between biodegradation kinetics and hydraulic conductivity distributions is of general interest and relevance to characterization and modeling of natural attenuation of hydrocarbons in other petroleum-product contaminated sites.

The precision with which the cosmological parameters have been determined has made dramatic progress in just the last two years. The author reviews this recent observational progress, highlights some of the key questions facing cosmology in the new millennium, and briefly discusses some of the projects now being mounted or contemplated to address them.

Groundwater flow and transport predictions are a major component of remedial action evaluations for contaminated groundwater at the Savannah River Site. Because all groundwater modeling results are subject to uncertainty from various causes; quantification of the level of uncertainty in the modeling predictions is beneficial to project decision makers. Complex site-specific models present formidable challenges for implementing an uncertainty analysis.

Recent results from the searches for new particles and phenomena using data collected by CDF are presented. Most results are from the data taken during 1994-95 period (Run I), but some preliminary results from the current data taking period (Run IIa) are presented as well.

Recent results on observations, properties and decay modes of the charmed and beauty baryons will be reviewed. Candidates for several new high mass states which include a cleanly-identified daughter {Lambda}{sub c}{sup +} baryon are seen in data from the SELEX experiment at Fermilab. These states are candidates for doubly-charmed baryons: a {Xi}{sub cc}{sup ++} state and a {Xi}{sub cc}{sup +} state. These candidates are more than 5{sigma} signals in each case at masses of 3520 and 3460 MeV respectively.

The LHC detectors are well into their construction phase. The LHC schedule shows first beam to ATLAS and CMS in 2007. Because the LHC accelerator has begun to plan for a ten fold increase in LHC design luminosity (the SLHC or super LHC) it is none too soon to begin to think about the upgrades which will be required of the present LHC detectors. In particular, the tracking systems of ATLAS and CMS will need to be completely rebuilt. Given the time needed to do the R & D, make prototypes, and construct the new detectors and given the accelerator schedule for the SLHC, work needs to begin rather soon.

VENUS (Versatile ECR ion source for NUclear Science) is a next generation superconducting ECR ion source, designed to produce high current, high charge state ions for the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. VENUS also serves as the prototype ion source for the RIA (Rare Isotope Accelerator) front end. The magnetic confinement configuration consists of three superconducting axial coils and six superconducting radial coils in a sextupole configuration. The nominal design fields of the axial magnets are 4T at injection and 3T at extraction; the nominal radial design field strength at the plasma chamber wall is 2T, making VENUS the world most powerful ECR plasma confinement structure. The magnetic field strength has been designed for optimum operation at 28 GHz. The four-year VENUS project has recently achieved two major milestones: The first plasma was ignited in June, the first mass-analyzed high charge state ion beam was extracted in September of 2002. The pa per describes the ongoing commissioning. Initial results including first emittance measurements are presented.