We have augmented the code POSINST to include solenoidfields, and used it to simulate the build up of electron cloud due toelectron multipacting in the PEP-II positron ring. We find that thedistribution of electrons is strongly affected by the resonancesassociated with the cyclotron period and bunch spacing. In addition, wediscover a threshold beyond which the electron density growsexponentially until it reaches the space charge limit. The threshold doesnot depend on the bunch spacing but does depend on the positron bunchpopulation.

The elements of the CKM matrix enter the expressions for the decay rates and mixing amplitudes of hadrons. In some cases, the theoretical expressions are free of strong interaction effects, for example the CP asymmetry in B {yields} J/{psi} K{sub S}{sup 0}, so that measuring the CP asymmetry directly gives the value of sin 2{beta}, with the error in the result given by the experimental error in the measurement. In most cases, however, the experimentally measured quantities depend on strong interactions physics, and it is absolutely essential to have accurate model-free theoretical calculations to compare with experiment. A number of theoretical tools have been developed over the years which now allow us to compute B decays with great accuracy, sometimes at the level of a few percent or better. These calculations are done using effective theory methods applied to QCD, and do not rely on model assumptions. Inclusive decays can be treated using the operator product expansion (OPE). The total decay rate is given by twice the imaginary part of the forward scattering amplitude, using the optical theorem. In heavy hadron decays, the intermediate states in the forward scattering amplitude can be integrated out, so that the decay rate can …

A second beamline, BL 7.2, completely dedicated to beam diagnostics is being installed at the Advanced Light Source (ALS). The design has been optimized for the measurement of the momentum spread and emittance of the stored beam in combination with the existing diagnostic beamline, BL 3.1. A detailed analysis of the experimental error has allowed the definition of the system parameters. The obtained requirements found a good matching with a simple and reliable system based on the detection of X-ray synchrotron radiation (SR) through a pinhole system. The actual beamline, which also includes a port for visible and infrared SR as well as an X-ray beam position monitor (BPM), is mainly based on the design of two similar diagnostic beamlines at BESSY II. This approach allowed a significant saving in time, cost and engineering effort. The design criteria, including a summary of the experimental error analysis, as well as a brief description of the beamline are presented.

Modeling coupled water-gas-rock interactions in unsaturated fractured rock requires conceptual and numerical model considerations beyond those developed for saturated porous media. This paper focuses on the integration of the geological and hydrological parameters into the calculation of reactive-transport parameters and the feedback of mineral precipitation/dissolution to flow and transport. These basic relations have been implemented in the reactive transport code TOUGHREACT (Xu et al., 2003) that couples equilibrium and kinetic water-gas-rock inter-actions with multiphase flow and aqueous and gaseous species transport. Simulation results are presented illustrating the effects of water-rock interaction accompanying the heating of unsaturated heterogeneous fractured tuff. Unknowns associated with modeling water-rock interaction in fractured unsaturated systems are the area of the fracture surface that is wetted and which fractures are active components of the overall flow system. The wetted fracture area is important not only to water-rock interaction but to flow and transport between fluids flowing in fractures and the adjacent matrix. The other unknown relations are those describing permeability and capillary pressure modification during mineral precipitation and dissolution. Here we discuss solely the relations developed for fractures and the fracture-matrix interface.

Previous analyses have assumed that wedge absorbers are triangularly shaped with equal angles for the two faces. In this case, to linear order, the energy loss depends only on the position in the direction of the face tilt, and is independent of the incoming angle. One can instead construct an absorber with entrance and exit faces facing rather general directions. In this case, the energy loss can depend on both the position and the angle of the particle in question. This paper demonstrates that and computes the effect to linear order.

Success in the application of the action and phase analysis to find linear errors at RHIC Interaction Regions [1] has encouraged the creation of a technique based on the action and phase analysis to find non linear errors. In this paper we show the first attempt to measure the sextupole components at RHIC interaction regions using the action and phase method. Experiments done by intentionally activating sextupoles in RHIC and in SPS [2] will also be analyzed with this method. First results have given values for the sextupole errors that at least have the same order of magnitude as the values found by an alternate technique during the RHIC 2001 run [3].

In most Cu(In,Ga)Se2 thin films used for solar cells, there usually exist interfaces lying about 0.1 to 0.2 m below the surfaces. We report on a convergent-beam electron diffraction and energy-dispersive X-ray spectroscopy study of the microstructure and chemical composition of the surface region in Cu(In,Ga)Se2 thin films. We find that the surface region and the bulk are structurally similar, with no ordered defect chalcopyrite structure observed. However, their composition is slightly different, indicating that they can have different point-defect physics. Our results suggest that the subinterfaces and the bulk absorber may form homojunctions.

Beam induced electron multipacting may be among the main reasons for the vacuum pressure rise when circulating high intensity ion and proton beams in RHIC. Latest simulation results are benchmarked with recent experimental observations for RHIC, and compared to other general computer codes. The influence of the electron multipacting to the vacuum properties is also discussed.

As one of the most critical system for RHIC operation, the beam abort kicker system has to be highly available, reliable, and stable for the entire operating range. Along with the RHIC commission and operation, consistent efforts have been spend to cope with immediate issues as well as inherited design issues. Major design changes have been implemented to achieve the higher operating voltage, longer high voltage hold-off time, fast retriggering and redundant triggering, and improved system protection, etc. Recent system test has demonstrated for the first time that both blue ring and yellow ring beam abort systems have achieved more than 24 hours hold off time at desired operating voltage. In this paper, we report break down, thyratron reverse arcing, and to build a fast re-trigger system to reduce beam spreading in event of premature discharge.

A future muon collider or neutrino factory requires fast acceleration to minimize muon decay. We have previously described an FFAG ring that accelerated muons from 10 to 20 GeV in energy. The ring achieved its large momentum acceptance using a low-emittance lattice with a small dispersion. In this paper, we present an update on that ring. We have used design tools that more accurately represent the ring's behavior at large momentum offsets. We have also improved the dynamic aperture from the earlier design.

During the summer of 2002, eight superconducting helical spin rotators were installed into RHIC in order to control the polarization directions independently at the STAR and PHENIX experiments. Without the rotators, the orientation of polarization at the interaction points would only be vertical. With four rotators around each of the two experiments, we can rotate either or both beams from vertical into the horizontal plane through the interaction region and then back to vertical on the other side. This allows independent control for each beam with vertical, longitudinal, or radial polarization at the experiment. In this paper, we present results from the first run using the new spin rotators at PHENIX.

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Alloy 22 (UNS N60622) is a nickel-based alloy, which is extensively used in aggressive industrial applications, especially due to its resistance to localized corrosion and stress corrosion cracking in high chloride environments. The purpose of this work was to characterize the anodic behavior of Alloy 22 in concentrated calcium chloride (CaCl{sub 2}) brines and to evaluate the inhibitive effect of nitrate, especially to localized corrosion. Standard electrochemical tests such as polarization resistance and cyclic polarization were used. Results show that the corrosion potential of Alloy 22 was approximately -360 mV in the silver-silver chloride (SSC) scale and independent of the tested temperature. Cyclic polarization tests showed that Alloy 22 was mainly susceptible to localized attack in 5 M CaCl{sub 2} at 75 C and higher temperatures. The addition of nitrate in a molar ratio of chloride to nitrate equal to 10 increased the onset of localized corrosion to approximately 105 C. The addition of nitrate to the solution also decreased the uniform corrosion rate and the passive current of the alloy.

Deuteron and gold beams have been accelerated to a collision energy of {radical}s = 200 GeV/u in the Relativistic Heavy Ion Collider (RHIC), providing the first asymmetric-species collisions of this complex. Necessary changes for this mode of operation include new ramping software and asymmetric crossing angle geometries. This paper reviews machine performance, problem encountered and their solutions, and accomplishments during the 16 weeks of ramp-up and operations.

This paper reviews the recent activities and accomplishments of the national Amorphous Silicon Team and a (crystalline) thin-film-Si subteam that was implemented in 2002 to research solar cell devices based on thin crystalline Si based layers. This paper reports the evolution of team organization, the technical highlights from the recent team meetings, and an outlook on commercialization potential.

An extensive peel-test study was conducted to investigate the various factors that may affect the adhesion strength of photovoltaic module encapsulants, primarily ethylene-vinyl acetate (EVA), on glass substrates of various laminates based on a common configuration of glass/encapsulant/backfoil. The results show that"pure" or"absolute" adhesion strength of EVA-to-glass was very difficult to obtain because of tensile deformation of the soft, semi-elastic EVA layer upon pulling. A mechanically"strong enough" backing foil on the EVA was critical to achieving the"apparent" adhesion strength. Peel test method with a 90-degree-pull yielded similar results to a 180-degree-pull. The 90-degree-pull method better revealed the four stages of delamination failure of the EVA/backfoil layers. The adhesion strength is affected by a number of factors, which include EVA type, formulation, backfoil type and manufacturing source, glass type, and surface priming treatment on the glass surface or on the backfoil. Effects of the glass-cleaning method and surface texture are not obvious. Direct priming treatments used in the work did not improve, or even worsened, the adhesion. Aging of EVA by storage over~5 years reduced notably the adhesion strength. Lower adhesion strengths were observed for the blank (unformulated) EVA and non-EVA copolymers, such as poly(ethylene-co-methacrylate) (PEMA) or poly(ethylene-co-butylacrylate) (PEBA). Their adhesion …

We summarize a recent calculation of perturbative neutrino cross sections that includes NLO and mass corrections. We provide numerical results for quantities that are related to the extraction of the weak mixing angle from neutrino deep inelastic scattering.

A wafer-bonded four-junction cell design consisting of InGaAs, InGaAsP, GaAs, and Ga0.5In0.5P subcells that could reach one-sun AM0 efficiencies of 35.4% is described. The design relies on wafer-bonding and layer transfer for integration of non-lattice-matched subcells. Wafer bonding and layer transfer processes have shown promise in the fabrication of InP/Si epitaxial templates for growth of the bottom InGaAs and InGaAsP subcells on a Si support substrate. Subsequent wafer bonding and layer transfer of a thin Ge layer onto the lower subcell stack can serve as an epitaxial template for GaAs and Ga0.5In0.5P subcells. Additionally, wafer bonded Ge/Si substrates offer the possibility to improve the mechanical performance of existing triple-junction solar cell designs, while simultaneously reducing their cost. Present results indicate that optically active III/V compound semiconductors can be grown on both Ge/Si and InP/Si heterostructures. Current-voltage electrical characterization of the interfaces of these structures indicates that both InP/Si and Ge/Si interfaces have specific resistances lower than 0.1 W?cm2 for heavily doped wafer bonded interfaces, enabling back surface power extraction from the finished cell structure.

The stockpile stewardship program is interested in neutron cross-section measurements on nuclei that are a few nucleons away from stability. Since neutron targets do not exist, radioactive targets are the only way to directly perform these measurements. This requires a facility that can provide high production rates for these short-lived nuclei as well as a source of neutrons. The Rare Isotope Accelerator (RIA) promises theses high production rates. Thus, adding a co-located neutron source facility to the RIA project baseline would allow these neutron cross-section measurements to be made. A conceptual design for such a neutron source has been developed, which would use two accelerators, a Dynamitron and a linac, to create the neutrons through a variety of reactions (d-d, d-t, deuteron break-up, p-Li). This range of reactions is needed in order to provide the desired energy range from 10's of keV to 20 MeV. The facility would also have hot cells to perform chemistry on the radioactive material both before and after neutron irradiation. The present status of this design and direction of future work will be discussed.

Recent increases in the efficiencies of phosphide, nitride, and organic light-emitting diodes (LEDs) inspire a vision of a revolution in lighting. If high efficiencies, long lifetimes, and low cost can be achieved, solid-state lighting could save our country many quads of electricity in the coming years. The solid-state lighting (SSL) and photovoltaic (PV) industries share many of the same challenges. This paper explores the similarities between the two industries and how they might benefit by sharing information.

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Fixed target studies of small branching ratio decay processes require intense beams and smooth spills. Longitudinal structure arises through collective effects, well below the coasting beam stability threshold. These structures have been observed at the Brookhaven AGS and dependence on intensity and momentum spread measured. Measurements and amelioration techniques have been developed and will be described.

We report on the pulsed laser deposition (PLD) of Mo-doped indium oxide (IMO) films with mobilities of up to 125 cm2/Vsec. Films have been grown from targets with 1-4 wt.% molybdenum. The optimum electrical and optical properties were obtained with the 2% target and yielded a maximum conductivity of 3717 S/cm with mobilities of 99 cm2/V-sec on (100) yttria stabilized zirconia (YSZ) single crystal substrates. Films also exhibit greater than 90% transparency in the visible range. Compared to commercial indium tin oxide (ITO) films, these PLD-grown IMO films have similar conductivity but since they have substantially higher mobility they have a correspondingly lower carrier concentration. The lower carrier concentration should extend the infrared window of the transparency for films of the same conductivity. This may lead to improved performance in a number of applications requiring improved performance TCOs.

We have investigated the spatial distribution of different transitions identified in the emission spectra of CdTe thin films and solar cells by cathodoluminescence spectroscopic imaging (CLSI). Prior to back-contact deposition, the spectra are dominated by excitons (X) and donor-to-acceptor (DAP) transitions. After contacting, Cu acceptor states are found in addition to the X and DAP recombination processes. A very systematic behavior found in CdTe is that DAP transitions occur preferentially at grain boundaries (GBs). The distribution of these states responsible for the passivation of GBs is not affected by further processing, although additional levels participate in the recombination process. We believe that this stability is one of the reasons for the success of thin-film CdTe solar cells. Estimates of the densities of different donors and acceptors participating in the recombination process are possible from the analysis of the evolution of the emission spectra with the excitation level. It is found that the back contact suppresses some intrinsic acceptors (associated with the A center) near the back-contact interface and, therefore, Cu acceptor states should be responsible for the p-typeness of the back surface more than a reduction of compensation. CLSI measurements are shown to be helpful in understanding the physics of …