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Research Progress Meeting of February 19, 1948

Description: Much of the cloud chamber work has been directed toward obtaining the angular distribution of protons bombarded by deuterons from the 184-inch cyclotron. The observations have been restricted to those protons arising from neutrons of energy greater than 65 Mev. The cloud chamber used for this work is of 16-inch diruneter and employs a magnetic field of 14000 gauss. The chamber is filled with hydrogen at a pressure of 1/2 atmosphere; the vapor used is water and alchohol. Nearly 800 proton tracks were measured and calculated before analysis of the data indicated that the measuring procedure should be revised. They gave the angular and energy distributions shown in Figures 1 and 2. The discrepencies between the theoretical and experimental energy distribution of the neutrons shows that serious errors were being made. As a first check of possible sources of error, random parts of the data were remeasured. They indicated that errors in the measurements of the angles were being made that gave a mean deviation of about {+-} 2{sup o} in the beam angle and {+-} 4{sup o} in the dip angle. These errors were largest at large scatter angles. In addition, a more serious error occured in the measurements of the curvature. The mean deviation was as large as 15 percent, with many tracks having errors of 50 to 100 percent in the measured curvature. These errors were dUd to the fact that an adequate measuring technique had not been developed, that the original measuring apparatus and projector were difficult to operate, and that the cloud chamber technique had not been perfected. A systematic analysis of the errors and difficulties involved in the experiment made it evident that revisions in the technique were necessary. In view of the inaccuracy of the original measurements it is not possible to make ...
Date: February 19, 1948
Creator: Wakerling, R.K.
Partner: UNT Libraries Government Documents Department

rSUGRA: Putting Nonuniversal Gaugino Masses on the (W)MAP

Description: In this talk, we investigate the relic density and direct detection prospects of rSUGRA, a simple paradigm for supersymmetry breaking that allows for nonuniversal gaugino masses. We present updated plots reflecting the latest cosmological measurements from WMAP.
Date: June 17, 2003
Creator: Birkedal-Hansen, Andreas
Partner: UNT Libraries Government Documents Department

Progress Report for 1947

Description: The year 1947 has witnessed the dawn of a new era of atomic science, a flowering of fundamental knowledge of the nature of matter which appears to be unsurpassed even by that period of the 1930's which led to the age of plutonium. A great new cyclotron, an atom-smasher ten times more powerful than the one which brought plutonium into the world, has carried mankind over a new horizon of sub-atomic space. It has brought scientists at last to grips with the infinitely small and rapid forces, until now beyond reach, which operate within the incredibly tiny distances of nuclear space. On the new energy frontier created by the giant machine, now laws govern nuclear reactions. methods are at hand, heretofore unavailable, which permit the measurement and determination of the nature of sub-atomic forces. Under ultra-high energy bombardment, the nucleus presents a different appearance from the nucleus of Bohr and Rutherford, the nucleus of atomic energy fission. The new exploration of the atom has been sponsored by the Atomic Energy Commission with the giant, new 4000-ton cyclotron in the Radiation Laboratory of the University of California. This is the thirdmajor machine built by the Director of the Laboratory and inventor of the cyclotron, Professor Ernest O. Lawrence. Whether the new knowledge will be of immediate practical consequence cannot now be predicted. Nor could Professor Lawrence predict, when in 1934 he established a new atomic energy range for that day with his first cyclotron, that the fundamental knowledge he pursued would be climaxed with the discovery of plutonium. What can be predicted is this: without the new basic knowledge, practical atomic developments of the future would be limited to the applicability of the fundamental information which made possible the initial release of atomic energy. In short, the nation's atomic potential has ...
Date: November 1, 1947
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department

Progress Report No. 69. Dec. 15, 1948 to Jan. 15, 1949

Description: This is the progress report for the University of California, Radiation Laboratory for December 15, 1948-January 15, 1949. It discusses the following: (1) Bevatron; (2) 184-inch Cyclotron Program; (3) 60-inch Cyclotron Program; (4) Synchrotron Operation; (5) Linear Accelerator and Van de Graaff Operation; (6) Experimental Physics; (7) Theoretical Physics, (8) Isotope Separation; (9) Chemistry Departments; (10) Medical Physics; and (11) Health Physics and Chemistry.
Date: January 30, 1949
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department

Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing

Description: Theoretical and experimental limits on the Higgs boson mass restrict CKM mixing of a possible fourth family beyond the constraints previously obtained from precision electroweak data alone. Existing experimental and theoretical bounds on m{sub H} already significantly restrict the allowed parameter space. Zero CKM mixing is excluded and mixing of order {theta}{sub Cabbibo} is allowed. Upper and lower limits on 3-4 CKM mixing are exhibited as a function of m{sub H}. We use the default inputs of the Electroweak Working Group and also explore the sensitivity of both the three and four family fits to alternative inputs.
Date: June 25, 2010
Creator: Chanowitz, Michael S.
Partner: UNT Libraries Government Documents Department

Interium Report on An Exact Analysis of a Limited Plane Plasma in a Magnetic Field

Description: Prior analyses of a plasma in a magnetic field have been limited, as far as the writer is aware, to cases in which the relative change in field over the orbital distance and the relative change in ion concentration are both small, or in which the relations have been viewed in a purely hydrodynamical way. The first approach excludes cases which can be of considerable interest, for it fails for a plasma edge. The second loses all sight of the structure imposed by the orbital motions.
Date: January 1, 1947
Creator: Tonka, Lewi
Partner: UNT Libraries Government Documents Department

Is the beta phase maximal?

Description: indicates that 2|Vub / Vcb/ Vus| = (1-z) with z given by z = 0.19 +(-) 0.14. This fact implies that irrespective of the form of the quark Yukawa matrices, the measured value of the SM CP phase beta is approximately the maximum allowed by the measured absolute values of the CKM elements. This is beta = pi/6 - z/sqrt{3} for gamma = pi/3 + z/sqrt{3}, which implies alpha = pi/2. Alternatively, assuming that beta is exactly maximal and using the experimental measurement, sin(2beta) = 0.726+(-) 0.037, the phase gamma is predicted to be gamma = pi/2 - beta = 66.3 +(-) 1.7. The maximality of beta, if confirmed by the near-future experiments, may give us some clues as to the origin of CP violation.
Date: April 20, 2005
Creator: Ferrandis, Javier & Ferrandis, Javier
Partner: UNT Libraries Government Documents Department

ISOLEUCYL-tRNA SYNTHETASE OF E. coli B. A RAPID KINETIC INVESTIGATION OF THE L-ISOLEUCINE ACTIVATING REACTION

Description: We have investigated the preequilibrium kinetics of the L-isoleucine activation reaction catalyzed by Ile-tRNA synthetase in the presence of a fluorescent reporter group, 2-p-toluidinylnaphthalene-6-sulfonate, using the stopped-flow technique. It is found that of all the reactants involved, L-isoleucine binds slowest to the enzyme, apparently in a two-step process. The kinetics of the reaction are invariant in the presence of co-reactants, whereas the kinetics for ATP are drastically changed in the presence of Mg{sup 2+} ions. The formation of enzyme bound L-isoleucyl {approx} AMP is conveniently followed at dilute concentrations. The value for the rate constant of formation was determined to be 135 sec{sup -1} and of the reverse process to be 670 sec{sup -1} at pH 8.0 25 C. These values are considerably higher than the rate constant 15 sec{sup -1} of the dissociation reaction for L-isoleucine. The value of the kinetically defined equilibrium constant between the ternary Michaelis-Menten complex and the ternary enzyme-product complex indicates that, at equilibrium, the Michaelis-Menten complex is favored. The effect of temperature has been determined, and a tentative interpretation of the thermodynamic parameters is offered. The zero standard enthalpy and positive entropy for binding of L-isoleucine is consistent with hydrophobic interactions, whereas the enzyme-ligand complexes for ATP and pyrophosphate might be stabilized by hydrogen-bonds and ion-ion interactions. The equilibrium constant of formation of the ternary enzyme-product complex from the Michaelis-Menten complex does not increase significantly with temperature. The types of kinetic pathways have been restricted to the alternative of a random mechanism or an ordered sequential mechanism in which L-iso-leucine binds first. We believe that the mechanism is random.
Date: May 1, 1972
Creator: Holler, E. & Calvin, Melvin
Partner: UNT Libraries Government Documents Department

The Production of Thin Be Foils

Description: A procedure for making Be foils between 10{sup -5} cm. and 10{sup -3} cm. thick, and with diameters up to an inch and a half is described, and methods of mounting these foils are indicated.The problem of making thin Be foils was presented in connection with focusing the proton beam in the Berkeley Linear Accelerator, and although the foils are not now used in the accelerator, they have proved to be quite useful as thin targets, target supports, thin windows, etc. The Be was evaporated in vacuum and deposited on a metal collector plate. The problems encountered were: (1) obtaining reproducible quantities of evaporated Be; (2) stripping of Be from the collector plates; (3) preventing curl of the foils when they were stripped; and (4) mounting the foils.
Date: March 18, 1948
Creator: Bradner, Hugh
Partner: UNT Libraries Government Documents Department

Progress Report No. 63 June 15-July 15, 1948

Description: This is the University of California, Radiation Laboratory progress report for June 15-July 15, 1948. It discusses the following: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Program; (3) Synchrotron Program; (4) Linear Accelerator Program; (5) Experimental Physics; (6) Theoretical Physics, (7) Isotope Separation Program; (8) Chemistry Departments; (9) Medical Physics; and (10) Health Physics and Chemistry.
Date: July 30, 1948
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department

Proton Decay and the Planck Scale

Description: Even without grand unification, proton decay can be a powerful probe of physics at the highest energy scales. Supersymmetric theories with conserved R-parity contain Planck-suppressed dimension 5 operators that give important contributions tonucleon decay. These operators are likely controlled by flavor physics, which means current and near future proton decay experiments might yield clues about the fermion mass spectrum. I present a thorough analysis of nucleon partial lifetimes in supersymmetric one-flavon Froggatt-Nielsen models with a single U(1)_X family symmetry which is responsible for the fermionic mass spectrum as well as forbidding R-parity violating interactions. Many of the models naturally lead to nucleon decay near present limits without any reference to grand unification.
Date: October 2, 2004
Creator: Larson, Daniel T.
Partner: UNT Libraries Government Documents Department

HIGH-INTENSITY EFFECTS IN THE LONGITUDINAL MOTION OF STORED PARTICLE BEAMS

Description: A brief review is given of the various self-field phenomena associated with the longitudinal motion of particles in storage rings. Although there are some high-intensity phenomena for which the coupling of longitudinal and transverse motion is essential, such as, for example, the headtail effect; the great majority of high-intensity phenomena primarily involve either longitudinal or transverse degrees of freedom. In this review, we restrict our attention to phenomena which are essentially longitudinal in nature. It is convenient to consider separately the behavior of unbunched (coasting) and bunched (external RF system in operation) beams. Detailed experimental information on coasting beams has been obtained on the ISR, on the (old) CERN electron model CESAR, and on electron ring accelerators. All high-energy electron storage rings have bunched beams and, of course, so do synchrotrons, so that there are a large number of sources of experimental information about the longitudinal motion of bunched beams.
Date: February 1, 1973
Creator: Sessler, Andrew M.
Partner: UNT Libraries Government Documents Department

Inelastic final-state interaction

Description: The final-state interaction in multichannel decay processes is systematically studied with application to B decay in mind. Since the final-state interaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like"Watson's theorem" holds for experimentally observed final states. We first examine in detail the two-channel problem as a toy-model to clarify the issues and to remedy common mistakes made in earlier literature. Realistic multichannel problems are too challenging for quantitative analysis. To cope with mathematical complexity, we introduce a method of approximation that is applicable to the case where one prominent inelastic channel dominates over all others. We illustrate this approximation method in the amplitude of the decay B to pi K fed by the intermediate states of a charmed meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonetheless we are able to obtain some insight in the issue and draw useful conclusions on general features on the strong phases.
Date: October 29, 2007
Creator: Suzuki, Mahiko & Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

AN INVESTIGATION OF THE ISOTOPES OF AMERICIUM AND CURIUM

Description: Isotopes of americium and curium with mass numbers less than 242 have been produced by cyclotron bombardment techniques, and several of their nuclear properties have been investigated. The partial alpha half-lives of Am{sup 239}, Cm{sup 241}, and Cm{sup 240} and the partial half-life for spontaneous fission of Cm{sup 240} were measured. The alpha decay daughter of Cm{sup 238} was found and evidence for the discovery of Am{sup 237} (an {approx}1 hour electron capture activity) and Cm{sup 239} (an {approx}10 hour electron capture activity) has been presented. An Appendix indicating the conditions for separation of the plus three actinides by selective elution from ion exchange resin with citric acid has been included.
Date: June 1, 1952
Creator: Higgins, Gary Hoyt.
Partner: UNT Libraries Government Documents Department

THE ISOTRON

Description: Most methods of separating isotopes depend on the use of a large magnetic field. The isotron is an electromagnetic device for separating isotopes, but it effects the separation by the use of radiofrequency voltages instead of magnetic fields. It has the advantage that plane sources of large area can be used instead of the slit sources to which most magnetic methods are limited. Before entering into any discussion of the details, a simplified description of the principles of the method is given.
Date: July 30, 1950
Creator: Wilson, R.R.
Partner: UNT Libraries Government Documents Department

THE LIFETIME OF AEROSOLS IN AMBIENT AIR: CONSIDERATION OF THE EFFECTS OF SURFACTANTS AND CHEMICAL REACTIONS

Description: The relatively long lifetime of droplets in atmospheric haze and fog in comparison with similar droplets of pure water is attributed to the presence of a monolayer of surfactant film and to the accumulation Of soluble salts from chemical reactions. The lifetime of these droplets is a significant factor in the evaluation of the role of heterogeneous aqueous chemical reactions occurring in the troposphere. Several mechanisms of SO{sub 2} oxidation in the presence of liquid water are investigated. It is shown that soot-catalyzed oxidation of sulfur dioxide could be responsible for the high level of sulfate concentration observed in the coastal industrial areas.
Date: April 1, 1984
Creator: Toossi, R. & Novakov, T.
Partner: UNT Libraries Government Documents Department

Half-Scale Model Tests on the Three Quarter Wave R.F. System for the 184-inch Frequency Modulated Cyclotron

Description: Performance curves and test results on a half scale model of the radio frequency system designed to accelerate protons in the Berkeley 184-inch cyclotron are presented. This report is a sequel to K. R. Mackenzie's report on the three quarter wave radio frequency system for frequency modulated cyclotrons.
Date: December 30, 1947
Creator: Anderson, Robert L.
Partner: UNT Libraries Government Documents Department

Semileptonic Form-factors from B-> K* gamma Decays in the Large Energy Limit

Description: Making use of the measurement of the $B\to K^*\gamma$ branching ratio together with the relations following from the limit of high recoil energy, we obtain stringent constraints on the values of the form-factors entering in heavy-to-light $B\to V\ell\ell'$ processes such as $B\to K^*\ell^+\ell^-$, $B\to K^*\nu \bar\nu$ and $B\to \rho\ell\nu$ decays. We show that the symmetry predictions, when combined with the experimental information on radiative decays, specify a severely restricted set of values for the vector and axial-vector form-factors evaluated at zero momentum transfer, $q^2=0$. These constraints can be used to test model calculations and to improve our understanding of the $q^2$-dependence of semileptonic form-factors. We stress that the constraints remain stringent even when corrections are taken into account.
Date: November 21, 2000
Creator: Burdman, Gustavo & Hiller, Gudrun
Partner: UNT Libraries Government Documents Department

THE ROLE OF THE CYCLOTRON IN MEDICAL RESEARCH

Description: The uses of radioactive isotopes in medical research can be conveniently divided into three principal categories; namely, the applications as tracers for the study of metabolic phenomena, as diagnostic aids in clinical medicine, and finally their role in therapy. Frequently radioisotopes available from the chain-reacting pile do not have a sufficient degree of specific activity for satisfactory use. A number of radioisotopes which can be produced with high specific activity in the pile possess half-lives too short to be of any practical value. Then, there are a few cases in which the desired radioisotope may be made in the pile with high specific activity, but concomitantly there is formed another radioisotope of the same element whose half-life is of such duration as to render its use hazardous in man. Finally, there are several elements of biological and medical interest whose radioactive isotopes can be produced only by the cyclotron.
Date: April 19, 1950
Creator: Hamilton, Joseph G.
Partner: UNT Libraries Government Documents Department

Bevatron Research Meeting I - Bevatron as a Research Instrument

Description: The Bevatron status is: (1) Physical structure of magnet now assembled and being tested. Initial pulsing to rated field currents indicate that magnet is performing as designed. Currents of the order of 8500 amps peak have already been rendered. (About 15,000 gauss). (2) Pumpdown time to approximately 10{sup -5} mm Hg is of the order of 24 hours at present but is expected to improve to 12-15 hours as the high vapor pressure solvents are removed. Lofgren and Brobeck expect that it will be possible to make interval target, etc., changes between operating shifts without excessive loss of experimental time. (3) Injector and linear accelerator are now operating stably. Injected currents to Linac are approximately 3 x 10{sup -3} peak at 450 kev. Linac output is approximately 5% or 70 x 10{sup -6} amps peak with an angular divergence of 10{sup -3} rad. and a maximum energy spread of less than 0.8% at 9.8 kev. (4) Inflector and induction electrodes are to be installed after December 15, 1953. (5) Complete machine, both mechanical and electrical, will be ready for testing and 'de-bugging' approximately December 15; 1953. Initial operation as a research instrument should begin after the first of the year, perhaps January 15, 1954 to January 30, 1954. (6) Magnetic testing started October 2 and will continue for approximately 6 weeks (until about November 15). (7) Concrete shielding will be installed around the southwest quadrant of the machine and at the south and west straight sections before research operations begin.
Date: October 6, 1953
Creator: Lofgren, Edward
Partner: UNT Libraries Government Documents Department

BEVATRON RESEARCH MEETING V - HIGH ENERGY NUCLEAR INTERACTION

Description: There are two different types of investigation of interest in high energy nuclear phenomena. One can observe gross effects such as the production of large numbers of heavy particles of different types, or one can study the elementary particles themselves which result from these collisions, for example, the kappa mesons, to determine modes of decay and the energy spectra of the resulting particles. This discussion will deal with the gross aspects of high energy interactions and will review the work of Fermi: High Energy Nuclear Interactions, Progress in Theoretical Physics, 5, No. 4, July-August, 1950.
Date: November 3, 1953
Creator: Lepore, Joseph
Partner: UNT Libraries Government Documents Department