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Fast energy spectrum and transverse beam profile monitoring and feedback systems for the SLC linac

Description: Fast energy spectrum and transverse beam profile monitoring systems have been tested at the SLC. The signals for each system are derived from digitizations of images on phosphor screens. Individual beam bunch images are digitized in the case of the transverse profile system and synchrotron radiation images produced by wiggler magnets for the energy spectrum. Measurements are taken at two-second intervals. Feedback elements have been installed for future use and consist of rf phase shifters to control energy spectrum and dipole correctors to control the beam launch into the linac affecting the transverse beam profile. Details of these systems, including hardware, timing, data acquisition, data reduction, measurement accuracy, and operational experience will be presented. 9 refs.
Date: March 1, 1989
Creator: Soderstrom, E.J.; Abrams, G.S.; Weinstein, A.J.; Brown, R.L.; Gromme, T.E.; Jacobsen, R.G. et al.
Partner: UNT Libraries Government Documents Department

Luminosity monitor at PEP

Description: The luminosity monitor system utilized by the MKII Detector and by the PEP operators is described. This system processes information from 56 photomultipliers and calculates independent luminosities for each of the 3 colliding bunches in PEP. Design considerations, measurement techniques, and sources of error in the luminosity measurement are discussed.
Date: February 1, 1981
Creator: Fox, J.D. & Franklin, M.E.B.
Partner: UNT Libraries Government Documents Department

Energy scaling, crab crossing and the pair problem

Description: Making reasonable assumptions, the luminosities of linear colliders are calculated for center-of-mass energies of 10 GeV, 100 GeV and 1 TeV. A calculation is also mode for a 1/2 TeV collider that could be upgraded to 1 TeV later. The improvements possible using ''crab-like'' crossing are also given. 4 refs., 4 figs., 3 tabs.
Date: December 1, 1988
Creator: Palmer, R.B.
Partner: UNT Libraries Government Documents Department

Channeled particle acceleration by plasma waves in metals

Description: A solid state accelerator concept utilizing particle acceleration along crystal channels by longitudinal electron plasma waves in a metal is presented. Acceleration gradients of order 100 GV/cm are theoretically possible. Particle dechanneling due to electron multiple scattering can be eliminated with a sufficiently high acceleration gradient. Plasma wave dissipation and generation in metals are also discussed.
Date: January 1, 1987
Creator: Chen, P. & Noble, R.J.
Partner: UNT Libraries Government Documents Department

Storage ring design optimization for FEL operation

Description: An electron beam in a storage ring seems to be a perfect driver for a free electron laser. The understanding of storage rings is very well advanced to project designs with high peak current, small beam sizes and short damping times. Since the beam is recycled after passage through the optical cavity we can expect a relatively high overall efficiency. On the other hand, however the fact that we do want the beam to circulate and interact with the laser field every turn puts a limit on the allowable perturbation of the beam due to the laser field. This limits the peak laser power we can get from a storage ring beam. The main advantage of a storage ring for FEL operation therefore is realized for continuous high power laser generation. In this paper we discuss some of the limitations in storage ring beam parameter as they pertain to FEL operation. The interaction of a FEL field with the beam, however, is not discussed here.
Date: November 1, 1982
Creator: Wiedemann, H.
Partner: UNT Libraries Government Documents Department

Chromatic corrections for large storage rings

Description: The use of achromat concept (1) to facilitate chromatic corrections in large storage rings is illustrated. The example given in this report is a lattice for a 75 GeV/c ring with six interaction regions having a beta x = 1.6 m, a beta y = 0.1 m and a luminosity of 1.4 10/sup 32/ cm/sup -2/s/sup -1/. The chromatic corrections are done with four families of sextupoles, two for each transverse plane, the strengths of which are determined by the solution of four linear equations in four unknowns. The basic simplicity of the method allows on-line control of the sextupole adjustments.
Date: February 1, 1979
Creator: Servranckx, R.V. & Brown, K.L.
Partner: UNT Libraries Government Documents Department

Air-core kicker magnets with and without metallic enclosure

Description: Estimations have been made for the design of air-core kicker magnets with the given specification, under the condition of having and without having an enclosure. It is found that the kicker magnet contained in a cylindrical enclosure of a radius equal to the spacing of the fields winding will require an amount double the electrical power and 40% more in excitation current. However, these quantities decrease rapidly with the increase of the cylinder's radius. It is recommended that a radius of 1.5 times, or more, of the winding's spacing should be used. Two curves are given to show the tendency of the power and current as a function of the enclosure's-radius-to-spacing ratio. The values obtained from the theoretical calculations are found to be in good agreement to those from computer calculations on a similar model. 5 figs., 6 tabs.
Date: April 1, 1978
Creator: Sun, Rai-Ko
Partner: UNT Libraries Government Documents Department

Summary of the 9th international symposium on high energy spin-physics

Description: Summarizing an international conference in high energy spin physics is never an easy task, because of the wide-ranging subjects in physics and technology that are involved. I have chosen to organize the topics of this conference into three broad categories relating to spin; intrinsic spin; composite spin; and spin, the experimental tool. In the first category, I will briefly revisit some historical and recent developments to set a background. In the second category, composite spin, I will discuss the status and developments in several areas, including magnetic moments of baryons, hyperon polarization in high energy high p {perpendicular} production, transverse polarization and asymmetries from transversely polarized targets in high p {perpendicular} scattering, spin structure of the proton, and the Bjorken sum rule. In the third category, I will discuss the steady, and at times rapid, progress in spin technology. In this part I include recent progress in high energy facilities, and comment on the highlights of the Workshops.
Date: November 1, 1990
Creator: Prescott, C.Y.
Partner: UNT Libraries Government Documents Department

Permanent magnet sextupole protocol and tolerances for the damping rings

Description: Response is given to various questions on alignment tolerances for the permanent magnet sextupoles (PMS's) in the damping rings. Consideration is given to rotational errors, strength/longitudinal placement errors, transverse placement errors, pitch/yaw or tilt errors, and harmonic field errors. Resulting error limits can be specified in terms of the maximum errors allowed in the distribution. (LEW)
Date: September 5, 1985
Creator: Spencer, J.E.
Partner: UNT Libraries Government Documents Department

Searching for an exotic lepton and gauge boson at high energy e/sup +/e/sup /minus// colliders

Description: The possibility of searching in high energy e/sup +/e/sup /minus// collisions for a singly produced heavy with an ordinary light lepton, e/sup +/e/sup /minus// ..-->.. L/sup +//ell//sup /minus//, has been investigated. The search is motivated mainly by its distinctive experimental signatures. In a data sample corresponding to an integrated luminosity of 30 fb/sup /minus/1/ collected at a 1 TeV e/sup +/e/sup /minus// collider, the search is sensitive to a lepton of mass up to about 1 TeV/c/sup 2/ and a production cross section as low as 10% of the ..mu..-pair point cross section. For the case where the process is mediated by an exotic gauge boson, sensitivity to a gauge boson of mass up to about 2 TeV/c/sup 2/ can be achieved. 5 refs., 7 figs., 2 tabs.
Date: January 1, 1989
Creator: Gan, K.K.
Partner: UNT Libraries Government Documents Department

Software management issues

Description: The difficulty of managing the software in large HEP collaborations appears to becoming progressively worst with each new generation of detector. If one were to extrapolate to the SSC, it will become a major problem. This paper explores the possible causes of the difficulty and makes suggestions on what corrective actions should be taken.
Date: June 1, 1990
Creator: Kunz, P.F.
Partner: UNT Libraries Government Documents Department

Beam dynamics verification in linacs of linear colliders

Description: The SLAC two-mile linac has been upgraded to accelerate high current, low emittance electron and positron beams to be used in the SLAC Linear Collider (SLC). After the upgrade was completed, extensive beam studies were made to verify that the design criteria have been met. These tests involved the measurement of emittance, beam phase space orientation, energy dispersion, trajectory oscillations, bunch length, energy spectrum and wakefields. The methods, the systems and the data cross checks are compared for the various measurements. Implications for the next linear collider are discussed. 12 refs., 13 figs., 2 tabs.
Date: January 1, 1989
Creator: Seeman, J.T.
Partner: UNT Libraries Government Documents Department

Single particle dynamics in circular accelerators

Description: The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)
Date: October 1, 1986
Creator: Ruth, R.D.
Partner: UNT Libraries Government Documents Department

Internal spin structure of the proton from high energy polarized e-p scattering

Description: A review is given of experimental knowledge of the spin dependent structure functions of the proton, which is based on inclusive high energy scattering of longitudinal polarized electrons by longitudinally polarized protons in both the deep inelastic and resonance regions, and includes preliminary results from our most recent SLAC experiment. Implications for scaling, sum rules, models of proton structure, and the hyperfine structure interval in hydrogen are given. Possible future directions of research are indicated.
Date: February 1, 1981
Creator: Hughes, V.W.; Baum, G. & Bergstroem, M.R.
Partner: UNT Libraries Government Documents Department

Non-linear sigma-models and string theories

Description: The connection between sigma-models and string theories is discussed, as well as how the sigma-models can be used as tools to prove various results in string theories. Closed bosonic string theory in the light cone gauge is very briefly introduced. Then, closed bosonic string theory in the presence of massless background fields is discussed. The light cone gauge is used, and it is shown that in order to obtain a Lorentz invariant theory, the string theory in the presence of background fields must be described by a two-dimensional conformally invariant theory. The resulting constraints on the background fields are found to be the equations of motion of the string theory. The analysis is extended to the case of the heterotic string theory and the superstring theory in the presence of the massless background fields. It is then shown how to use these results to obtain nontrivial solutions to the string field equations. Another application of these results is shown, namely to prove that the effective cosmological constant after compactification vanishes as a consequence of the classical equations of motion of the string theory. 34 refs. (LEW)
Date: October 1, 1986
Creator: Sen, A.
Partner: UNT Libraries Government Documents Department

Experimental tests of quantum chromodynamics

Description: Experimental tests of quantum chromodynamics are discussed in the e/sup +/e/sup -/ continuum, in pp and anti p p collisions, in measurements of ..cap alpha../sub s/ from UPSILON decays, in deep inelastic lepton scattering, and in the measurement of the photon structure function. A large body of data relating to the testing of quantum chromodynamics is reviewed, showing qualitative agreement between the data from a wide range of processes and QCD. 66 refs., 79 figs. (LEW)
Date: April 1, 1987
Creator: Dorfan, J.
Partner: UNT Libraries Government Documents Department

Electromagnetic fields in axial symmetric waveguides with variable cross section

Description: A new class of separable variables is found which allows one to find an approximate analytical solution of the Maxwell equations for axial symmetric waveguides with slow (but not necessarily small) varying boundary surfaces. An example of the solution is given. Possible applications and limitations of this approach are discussed. 6 refs., 10 figs.
Date: February 15, 1980
Creator: Kheifets, S.
Partner: UNT Libraries Government Documents Department

Recent measurements of the average lifetime of hadrons containing B-quarks from PEP experiments at SLAC (Stanford Linear Accelerator Center)

Description: Recent precise results from several experiments have confirmed the early evidence that the lifetime of hadrons containing B-quarks is rather long, implying that the third generation of quarks is more decoupled from the first two than the second is from the first. The average of the measurements performed by the experiments at PEP is 1.08 +- 0.13 ps.
Date: May 1, 1987
Creator: Camporesi, T.
Partner: UNT Libraries Government Documents Department

Finite-particle-number approach to physics

Description: Starting from a discrete, self-generating and self-organizing, recursive model and self-consistent interpretive rules we construct: the scale constants of physics (3,10,137,1.7x10/sup 38/); 3+1 Minkowski space with a discrete metric and the algebraic bound ..delta.. is an element of ..delta.. tau is greater than or equal to 1; the Einstein-deBroglie relation; algebraic double slit interference; a single-time momentum-space scattering theory connected to laboratory experience; an approximation to wave functions; local phase severance and hence both distant correlations and separability; baryon number, lepton number, charge and helicity; m/sub p//m/sub e/; a cosmology not in disagreement with current observations.
Date: October 1, 1982
Creator: Noyes, H.P.
Partner: UNT Libraries Government Documents Department

Modeling a horizontal wiggler in an electron storage ring

Description: The effects of a wiggler on the beam parameters depend on several integrals involving the machine functions and the field distribution in the wiggler. It is shown that these integrals are separable into sums of products of terms containing only the initial values of the machine functions, and terms containing integrals over the wiggler fields. The field-dependent integrals may be determined by numerical integrations based on measured field distribution. In typical wiggler designs, the energy and excitation dependencies of the integrals may be modeled mathematically by simple power series.
Date: February 1, 1979
Creator: Helm, R.H.
Partner: UNT Libraries Government Documents Department

Component and system tests of the SLD Cerenkov Ring Imaging Detector

Description: The components of the SLD barrel Cerenkov Ring Imaging Detector (CRID) are now built and are being installed. We report on tests of these components, including tests of the fiber optic calibration system, detailed studies of electron drift paths on production drift boxes and detectors, tests of the dynamic gating systems and its effect on drift path distortions due to space-charge, and a measurement of the electron lifetime in a production drift box. In addition, we report on the UV transmission of recirculated liquid freon and on the effects of CRID construction materials on electron lifetime. 16 refs., 12 figs.
Date: October 1, 1990
Creator: Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S. et al.
Partner: UNT Libraries Government Documents Department

The strangeonium spectrum seen in LASS; implications for glueball spectroscopy

Description: The status of strangeonium spectroscopy is re-assessed following our recent high statistics study of K/sup /minus// induced hypercharge exchange reactions. The implications of our results for the status of glueball, or otherwise exotic, candidates observed in the same decay modes but produced by different mechanisms are also discussed. 11 refs., 8 figs.
Date: October 1, 1988
Creator: Aston, D.; Awaji, N.; Bienz, T.; Bird, F.; D'Amore, J.; Dunwoodie, W. et al.
Partner: UNT Libraries Government Documents Department

Performance measurements of hybrid PIN diode arrays

Description: We report the successful development of hybrid PIN diode arrays and a series of room-temperature measurements in a high-energy pion beam at FNAL. A PMOS VLSI 256 {times} 256 readout array having 30 {mu}m square pixels was indium-bump bonded to a mating PIN diode detector array. Preliminary measurements on the resulting hybrid show excellent signal-to-noise at room temperature. 3 refs., 5 figs.
Date: October 1, 1990
Creator: Shapiro, S.L. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)); Arens, J.F.; Jernigan, J.G. (California Univ., Berkeley, CA (USA). Space Sciences Lab.); Kramer, G. (Hughes Aircraft Co., El Segundo, CA (USA)); Collins, T.; Worley, S. (Hughes Aircraft Co., Carlsbad, CA (USA)) et al.
Partner: UNT Libraries Government Documents Department

Testing GUTs: where do monopoles fit

Description: The report shows why the inadequacies of the standard model of elementary particles impel some theorists toward embedding the strong, weak and electromagnetic interactions in a simple GUT group, and explains why the grand unification scale and hence the GUM (Grand Unified Monopoles) mass are expected to be so large (greater than or equal to 10/sup 14/ GeV). It goes on to describe some model GUTs, notably minimal SU(5) and supersymmetric (susy) GUTs. The grand unified analogues of generalized Cabibbo mixing angles are introduced relevant to the prediction of baryon decay modes in different theories as well as to the Decay modes catalyzed by GUMs. Phenomenologies of conventional and susy GUTs are contrasted including the potential increase in the grand unification scale as well as possible different baryon decay modes in susy GUTs. The phenomenology of GUMs is discussed, principally their ability to catalyze baryon decays. Some of the astrophysical and cosmological constraints on GUMs, GUMs, which make it difficult to imagine ever seeing a GUM and may impose serious restrictions on GUT model-building via their behavior in the very early universe are introduced. Finally, the reasons why GUMs are crucial aspects and tests of GUTs are summarized.
Date: October 1, 1982
Creator: Ellis, J.
Partner: UNT Libraries Government Documents Department