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New particles and interactions

Description: The Working Group on New Particles and Interactions met as a whole at the beginning and at the end of the Workshop. However, much of what was accomplished was done in five subgroups. These were devoted to: (1) new quarks and leptons; (2) technicolor; (3) supersymmetry; (4) rare decays and CP; and (5) substructure of quarks and leptons. Other aspects of new particles, e.g., Higgs, W', Z', fell to the Electroweak Working Group to consider. The central question of this Workshop of comparing anti pp (with L = 10/sup 32//cm/sup 2/-sec) with pp (with L = 10/sup 33//cm/sup 2/-sec) colliders carried through to all these subgroups. In addition there were several other aspects of hadron colliders which were considered: what does an increase in ..sqrt..s gain in cross section and resultant sensitivity to new physics versus an increase in luminosity; will polarized beams or the use of asymmetries be essential in finding new interactions; where and at what level do rate limitations due to triggering or detection systems play a role; and how and where will the detection of particles with short, but detectable, lifetimes be important. 25 references.
Date: April 1, 1984
Creator: Gilman, F. J. & Grannis, P. D.
Partner: UNT Libraries Government Documents Department

Heavy ion inertial fusion: interface between target gain, accelerator phase space and reactor beam transport revisited

Description: Recently revised estimates of target gain have added additional optimistic inputs to the interface between targets, accelerators and fusion chamber beam transport. But it remains valid that neutralization of the beams in the fusion chamber is useful if ion charge state Z > 1 or if > 1 kA per beamlet is to be propagated. Some engineering and economic considerations favor higher currents.
Date: February 22, 1984
Creator: Barletta, W. A.; Fawley, W. M.; Judd, D. L.; Mark, J. W. K. & Yu, S. S.
Partner: UNT Libraries Government Documents Department

PEP Conceptual Design Report

Description: The accelerator system design, the physical plant, the experimental areas, cost estimates, and schedules for PEP are discussed. The main component of the proposed facility is a storage ring in which beams of positrons and electrons circulate in opposite directions in a vacuum chamber embedded in a magnetic guide field having six bending arcs and six long straight sections. The electrons and positrons to be stored in it are produced in the SLAC linac and are introduced into the storage ring via two beam transport paths emanating from the end of the two-mile accelerator. Beams of energies up to 18 GeV can be stored, and, at a future date, components could be added to permit energies as high as 22 GeV. Provisions are also made in the design of the ring housing so that a synchrotron-radiation research facility could be added in the future. The energy lost from the beams by synchrotron radiation is restored by a high-power radio frequency accelerating system which employs klystrons to drive the accelerating structures at a frequency of 353 MHz. The system is capable of delivering five megawatts of power to the beams. Low pressures will be sustained by means of long, narrow sputter-ion pumps located in the vacuum chamber in the bending magnets directly alongside the beams. The proposed storage ring is designed to generate a luminosity (reaction rate per unit reaction cross section) of more than 10/sup 31/ cm/sup -2/sec/sup -1/ per interaction region at beam energies between 5 GeV and 18 GeV and a maximum luminosity of 10/sup 32/cm/sup -2/sec/sup -1/ per interaction region at a beam energy of 15 GeV.
Date: February 1, 1976
Partner: UNT Libraries Government Documents Department

Construction and testing of the SLD Cerenkov Ring Imaging Detector

Description: We report on the construction of the Cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider and the testing of its components. We include results from testing the drift boxes, liquid radiator trays, and mirrors for the barrel CRID. We also discuss development of the support systems essential for the operation of the CRID: gas and liquid recirculator systems and monitoring. 15 refs., 9 figs.
Date: January 1, 1990
Creator: Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Williams, D. A.; Zucchelli, P. (California Univ., Santa Cruz, CA (USA). Inst. for Particle Physics) et al.
Partner: UNT Libraries Government Documents Department

Report of the Central Tracking Group

Description: Issues involved in building a realistic central tracking system for a general-purpose 4..pi.. detector for the SSC are addressed. Such a central tracking system must be capable of running at the full design luminosity of 10/sup 33/ cm/sup -2/s/sup -1/. Momentum measurement was required in a general-purpose 4..pi.. detector. Limitations on charged particle tracking detectors at the SSC imposed by rates and radiation damage are reviewed. Cell occupancy is the dominant constraint, which led us to the conclusion that only small cells, either wires or straw tubes, are suitable for a central tracking system at the SSC. Mechanical problems involved in building a central tracking system of either wires or straw tubes were studied, and our conclusion was that it is possible to build such a large central tracking system. Of course, a great deal of research and development is required. We also considered central tracking systems made of scintillating fibers or silicon microstrips, but our conclusion was that neither is a realistic candidate given the current state of technology. We began to work on computer simulation of a realistic central tracking system. Events from interesting physics processes at the SSC will be complex and will be further complicated by hits from out-of-time bunch crossings and multiple interactions within the same bunch crossing. Detailed computer simulations are needed to demonstrate that the pattern recognition and tracking problems can be solved.
Date: October 1, 1986
Creator: Cassel, D. G. & Hanson, G. G.
Partner: UNT Libraries Government Documents Department

A study of strange and strangeonium states produced in LASS (Large Aperture Superconducting Solenoid)

Description: Results are presented from the analysis of several final states from a high-sensitivity (4 ev/nb) study of inelastic K/sup -/p interactions at 11 GeV/c carried out in the LASS Spectrometer at SLAC. New information is reported on leading and underlying K* states, and the strangeonium states produced by hypercharge exchange exchange are compared and contrasted with those observed in radiative decays of the J/psi. 8 refs., 15 figs.
Date: January 1, 1986
Creator: Aston, D.; Awaji, N.; Bienz, T.; Bird, F.; D'Amore, J.; Dunwoodie, W. et al.
Partner: UNT Libraries Government Documents Department

Heavy Ion Fusion Systems Assessment study

Description: The Heavy Ion Fusion Systems Assessment (HIFSA) study was conducted with the specific objective of evaluating the prospects of using induction linac drivers to generate economical electrical power from inertial confinement fusion. The study used algorithmic models of representative components of a fusion system to identify favored areas in the multidimensional parameter space. The resulting cost-of-electricity (COE) projections are comparable to those from other (magnetic) fusion scenarios, at a plant size of 100 MWe.
Date: July 1, 1986
Creator: Dudziak, D. J. & Herrmannsfeldt, W. B.
Partner: UNT Libraries Government Documents Department

Anisotropic phase separation in amorphous Fe--Ge alloys

Description: Magnetron sputtered amorphous Fe[sub x]Ge[sub 100-x] films have been examined with anomalous small-angle x-ray scattering (ASAXS) in an attempt to characterize composition fluctuations which have been previously reported in this system. Films grown under various deposition conditions have been studied, with the scattering vector both in and oblique to the plane of the films, to search for anisotropy. By manipulating the deposited power flux and rates of growth, films which have the same composition can be grown to different states of phase separation. The total correlation functions have been calculated from the oblique scattering experiments. The anisotropy can be successfully modeled as a close-packing of oriented prolate ellipsoidal particles, with the elongated axis along the direction of film growth. A method for using these measurements to determine the compositions of the phase-separating species has been developed and utilized. The results indicate phase separation into a-Ge and a-FeGe[sub 2] for the a-Fe[sub x]Ge[sub 100-x] (x<33) alloy.
Date: April 1, 1993
Creator: Regan, M. J. & Bienenstock, A.
Partner: UNT Libraries Government Documents Department

Recent progress in Cerenkov ring imaging for the SLD experiment

Description: Results of recent beam tests of a physics prototype Cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider (SLC) are presented. The system includes both liquid (C/sub 6/F/sub 14/) and gas (isobutane) radiators and an 80 cm long Time Projection Chamber (TPC) with a gaseous TMAE (Tetrakis-Dimethylamino-Ethylene) photocathode and charge division readout of proportional wires. Handling of TMAE and development of a gas delivery system are discussed. Design considerations for the construction of the TPC anode planes are presented. Measurements of the multiplicity of detected Cerenkov photons, of Cerenkov angles, and the resolution with both radiators are presented. The particle identification capability of this detector is discussed.
Date: August 1, 1986
Creator: Ashford, V.; Bienz, T.; Bird, F.; Gaillard, M.; Hallewell, G.; Leith, D. et al.
Partner: UNT Libraries Government Documents Department

Search for backwards produced exotic meson resonances and study of particle spectra and mass distributions in the reaction. pi. /sup +/ + P. -->. n (forward) + X/sup + +/ at 8. 4 GeV/c. [Upper limits, G parity, 8. 4 GeV/c]

Description: Results are reported from a hybrid experiment designed to search for backwards produced I = 2 exotic meson resonances by investigating the backward scattering reactions: ..pi../sup +/ + p ..-->.. in (forward) + ..pi../sup +/..pi../sup +/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/..pi../sup -/, and p anti p..pi../sup +/..pi../sup +/ at an incident pion momentum of 8.4 GeV/c. The SLAC 15'' rapid cycling bubble chamber, operating at 20 cycles per second, was triggered by detecting fast forward neutrons in an optical spark chamber and scintillation counter array downstream. Following two-component duality arguments, Jacob and Weyers and Rosner have suggested backward scattering processes as a favored mode for exotic meson resonance production. Upper limits of the order of one microbarn are reported for the production of narrow exotic meson resonances with masses less than or equal to 3 GeV and which could decay into even G-parity states: ..pi../sup +/..pi../sup +/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/..pi../sup -/, and p anti p..pi../sup +/..pi../sup +/. The mass resolution in the above channels varied from 5 to 30 MeV over the mass range for the most restrictive sample of events. The statistical significance of the data corresponds to 30 events per microbarn. Evidence for forward N* and rho/sup 0/ production are also reported. The main features of the data can be simulated by a Monte Carlo model which incorporates Lorentz-invariant phase space modified by exponential transverse momentum damping on each final state particle and, in addition, takes into account the geometrical constraints and trigger requirements of the experiment.
Date: August 1, 1975
Creator: Alam, M. S.; Brabson, B. B. & Galloway, K.
Partner: UNT Libraries Government Documents Department

Twisted strings and orbifolds

Description: Orbifold compactifications provide a practical approach to string symmetry breaking. They have the potential to bridge the gap between string theory and the physics of the standard model. 7 refs., 5 figs.
Date: August 1, 1986
Creator: Bagger, J. A.
Partner: UNT Libraries Government Documents Department

The EGS4 Code System: Solution of gamma-ray and electron transport problems

Description: In this paper we present an overview of the EGS4 Code System -- a general purpose package for the Monte Carlo simulation of the transport of electrons and photons. During the last 10-15 years EGS has been widely used to design accelerators and detectors for high-energy physics. More recently the code has been found to be of tremendous use in medical radiation physics and dosimetry. The problem-solving capabilities of EGS4 will be demonstrated by means of a variety of practical examples. To facilitate this review, we will take advantage of a new add-on package, called SHOWGRAF, to display particle trajectories in complicated geometries. These are shown as 2-D laser pictures in the written paper and as photographic slides of a 3-D high-resolution color monitor during the oral presentation. 11 refs., 15 figs.
Date: February 9, 1990
Creator: Nelson, W. R. & Namito, Yoshihito.
Partner: UNT Libraries Government Documents Department

Sector 30 collimator radiation

Description: The collimators at Sector 30 of the SLAC accelerator are designed to scrape off a significant fraction (e.g., {approximately}20%) of the SLC beam. The electromagnetic cascade shower that develops in the collimator, and in the scraper and waveguide downbeam, leads to very high radiation exposures of TV cameras (and other devices) located nearby. The collimator (point) source accounts for one-third of the dose and is best shielded by extending the radius of the copper scraper. Radiation from the waveguide accounts for the remaining two-thirds of the dose, and is difficult to shield since it is a line source. However, the spectrum from the waveguide is expected to be softer than that from the collimator. This paper discusses shielding of these sources.
Date: February 22, 1990
Creator: Namito, Y. (Ship Research Inst., Tokyo (Japan)); Nelson, W. R. & Benson, E.
Partner: UNT Libraries Government Documents Department

Scalable coherent interface

Description: The Scalable Coherent Interface (IEEE P1596) is establishing an interface standard for very high performance multiprocessors, supporting a cache-coherent-memory model scalable to systems with up to 64K nodes. This Scalable Coherent Interface (SCI) will supply a peak bandwidth per node of 1 GigaByte/second. The SCI standard should facilitate assembly of processor, memory, I/O and bus bridge cards from multiple vendors into massively parallel systems with throughput far above what is possible today. The SCI standard encompasses two levels of interface, a physical level and a logical level. The physical level specifies electrical, mechanical and thermal characteristics of connectors and cards that meet the standard. The logical level describes the address space, data transfer protocols, cache coherence mechanisms, synchronization primitives and error recovery. In this paper we address logical level issues such as packet formats, packet transmission, transaction handshake, flow control, and cache coherence. 11 refs., 10 figs.
Date: January 1, 1990
Creator: Alnaes, K.; Kristiansen, E. H. (Dolphin Server Technology A. S., Oslo (Norway)); Gustavson, D. B. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)) & James, D. V. (Apple Computer, Cupertino, CA (USA))
Partner: UNT Libraries Government Documents Department

Computation and control with neural nets

Description: As energies have increased exponentially with time so have the size and complexity of accelerators and control systems. NN may offer the kinds of improvements in computation and control that are needed to maintain acceptable functionality. For control their associative characteristics could provide signal conversion or data translation. Because they can do any computation such as least squares, they can close feedback loops autonomously to provide intelligent control at the point of action rather than at a central location that requires transfers, conversions, hand-shaking and other costly repetitions like input protection. Both computation and control can be integrated on a single chip, printed circuit or an optical equivalent that is also inherently faster through full parallel operation. For such reasons one expects lower costs and better results. Such systems could be optimized by integrating sensor and signal processing functions. Distributed nets of such hardware could communicate and provide global monitoring and multiprocessing in various ways e.g. via token, slotted or parallel rings (or Steiner trees) for compatibility with existing systems. Problems and advantages of this approach such as an optimal, real-time Turing machine are discussed. Simple examples are simulated and hardware implemented using discrete elements that demonstrate some basic characteristics of learning and parallelism. Future microprocessors' are predicted and requested on this basis. 19 refs., 18 figs.
Date: October 4, 1989
Creator: Corneliusen, A.; Terdal, P.; Knight, T. & Spencer, J.
Partner: UNT Libraries Government Documents Department

A finite Zitterbewegung model for relativistic quantum mechanics

Description: Starting from steps of length h/mc and time intervals h/mc{sup 2}, which imply a quasi-local Zitterbewegung with velocity steps {plus minus}c, we employ discrimination between bit-strings of finite length to construct a necessary 3+1 dimensional event-space for relativistic quantum mechanics. By using the combinatorial hierarchy to label the strings, we provide a successful start on constructing the coupling constants and mass ratios implied by the scheme. Agreement with experiments is surprisingly accurate. 22 refs., 1 fig.
Date: February 19, 1990
Creator: Noyes, H. P.
Partner: UNT Libraries Government Documents Department

Initial performance of the Wire Imaging Synchrotron Radiation Detector

Description: This paper describes the initial performance of a novel detector that measures the positions of intense synchrotron-radiation beams with high precision. Two detectors of this kind are used for the precision energy spectrometers of the Stanford Linear Collider (SLC). The detectors accurately determine the distance between pairs of intense synchrotron beams of typically 1 MeV photons, which are emitted by the primary electron and positron beams of the SLC. The detectors intercept the synchrotron beams with arrays of fine wires. The ejection of Compton-recoil electrons leaves positive charges on the wires, enabling a determination of beam positions. 6 refs., 6 figs.
Date: January 1, 1990
Creator: Von Zanthier, C.; Gomez Cadenas, J. J.; Kent, J.; King, M.; Watson, S. (California Univ., Santa Cruz, CA (USA)); Briggs, D. D. et al.
Partner: UNT Libraries Government Documents Department

Linac BPM (Beam Position Monitor) modification program status

Description: In the fall of 1988 the Beam Position Monitor (BPM) Task Force recommended that linac BPM processors be pulled out of the linac, modified, adjusted for offsets, recalibrated, and reinstalled. As of the end of 1989 this process had been completed on all linac type BPM processors. This paper discusses these modifications and tests.
Date: February 10, 1990
Creator: Smith, S. & Williams, S.
Partner: UNT Libraries Government Documents Department

The Inevitable Universe---Parker-Rhodes' peculiar mixture of ontology and physics

Description: When asked to give a lecture on Parker-Rhodes' physics, I was somewhat non-plused. I almost replied What physics '' --- a point of view that Frederick expresses himself more than once in the book he was working on when he died. But that would be unjust. Whatever his view, I assert that the discovery of the Combinational Hierarchy is one of the most important discoveries'' --- or whatever you want to call it --- in physics made in this century. His calculation of the proton-electron mass ratio is also a fantastic result that we are still trying to come to grips with. And his insight into early cosmology --- what he called a cold big bang'' --- which appeared in an early version of the Theory of Indistinguishables, also had merit. His early universe is a lot closer to my own views now than I realized when I first encountered it. We will mention other insights as I go along. But his views are so different from those of anyone I know or knew, that I have decided to let him speak for himself by reading passages from his manuscript The Inevitable Universe, or TIU, which was still unpublished at the time of his death, and add a few comments on them.
Date: December 1, 1989
Creator: Noyes, H. P.
Partner: UNT Libraries Government Documents Department

Viewing MORSE-CG radiation transport with 3-D color graphics

Description: In this paper we present the coupling of MORSE-CG with the SLAC Unified Graphics System (UGS77) through an add-on package called MORSGRAF which allows for real-time display of neutron and photon tracks in the Monte Carlo simulation. In addition to displaying the myriad of complicated geometries that can be created with the MORSE Combinatorial Geometry program, MORSGRAF permits color tagging of neutrons (green) and photons (red) with the variation of track intensity an indicator of the energy of the particle. Particle types can be switched off and on by means of a mouse-icon system, and the perspective can be changed (i.e., rotated, translated, and zoomed). MORSGRAF also allows one to display the propagation of radiation through shields and mazes on an ordinary graphics terminal, as well as in documents printed on a laser printer. Several examples will be given to demonstrate the various capabilities of MORSGRAF coupled to MORSE-CG. 12 refs., 8 figs.
Date: January 1, 1990
Creator: Namito, Yoshihito; Jenkins, T. M. & Nelson, W. R.
Partner: UNT Libraries Government Documents Department

Applied chromodynamics

Description: A number of novel features of QCD are reviewed, including the consequences of formation zone and color transparency phenomena in hadronic collisions, the use of automatic scale setting for perturbative predictions, null-zone phenomena as a fundamental test of gauge theory, and the relationship of intrinsic heavy colored particle Fock state components to new particle production. We conclude with a review of the applications of QCD to nuclear multiquark systems. 74 references.
Date: November 1, 1983
Creator: Brodsky, S. J.
Partner: UNT Libraries Government Documents Department

The analog processing system for the Liquid Argon Calorimeter for SLD at SLAC

Description: The analog processing system for the Liquid Argon Calorimeter for the SLD project at SLAC is described. Amplification, storage of the analog information, and multiplexing is realized on specially developed hybrids, which will be mounted directly on the detector. This leads to a substantial reduction of the cable plant. Test results for the amplifier and for the sampling and multiplexing hybrid (CDU hybrid) are presented. The latter hybird contains a custom monolithic device, the Calorimeter Data Unit (CDU).
Date: September 1, 1986
Creator: Haller, G. M.; Nelson, D. & Freytag, D. R.
Partner: UNT Libraries Government Documents Department