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Is the momentum space optimally used with the FODO lattices?

Description: The available momentum space of a FODO lattice is determined by the maximum value of the dispersion function ({delta}x = D{sub x} {partial_derivative}p/p). In a regular FODO lattice the dispersion function oscillates between its maximum and minimum values, which are always positive. The maximum value of the dispersion function in a FODO cell of a fixed length depends on the cell phase difference. An example of a new lattice, in which the dispersion function is lowered to half its value in the same FODO cell, is presented. ne available momentum space in the new lattice is raised to twice that in the FODO lattice by allowing the dispersion function to oscillate between the same positive and negative values. The maxima of the dispersion function in the new lattice have half the value of those within the regular 900 cells.
Date: July 1, 1993
Creator: Trbojevic, D.; Ng, K.Y. & Lee, S.Y.
Partner: UNT Libraries Government Documents Department

[Analysis of momentum and impurity confinment in TFTR (1990)]

Description: Work during the present grant period has been concentrated in two areas and are discussed in this report: (1) a review of momentum confinement experiments in tokamaks, of momentum confinement theories and of previous comparisons of the two; and (2) analysis and documentation of the dedicated power-scan rotation experiment performed on TFTR in September 1988.
Date: December 31, 1990
Partner: UNT Libraries Government Documents Department

Energy and momentum conserving algorithms for rigid body contact

Description: Energy-momentum conserving methods are developed for rigid body dynamics with contact. Because these methods are unconditionally stable, they are not time step dependent and, hence, are well suited for incorporation into structural mechanics finite element codes. Both penalty and Lagrange multiplier methods are developed herein and are the extension of the energy-momentum conserving integration schemes for rigid bodies given by Simo and Wong [1].
Date: April 9, 1998
Creator: Puso, M.A. & Zywicz, E.
Partner: UNT Libraries Government Documents Department

Status of the variable momentum compaction storage ring experiment in SPEAR

Description: Variable momentum compaction lattices have been proposed for electron-positron colliders and synchrotron radiation sources to control synchrotron tune and bunch length. To address questions of single particle stability limits, a study has been initiated to change the SPEAR lattice into a variable momentum compaction configuration for experimental investigation of the beam dynamics. In this paper, we describe a model-based method used to transform SPEAR from the injection lattice to the low momentum compaction configuration. Experimental observations of the process are reviewed.
Date: September 1, 1993
Creator: Tran, P.; Amiry, A. & Pellegrini, C.
Partner: UNT Libraries Government Documents Department

Overview, goals, and preliminary results of E910 laboratory directed research and development at Lawrence Livermore National Laboratory

Description: E910 is a large acceptance proton-nucleus experiment at the BNL AGS. The experiment completed its first run in the Spring of 1996, collecting more than 20 million pA events, using Be, Cu, Au, and U targets. We present preliminary results for momentum conservation, slow proton distributions, and dN/dy for negative tracks. 16 refs., 5 figs.
Date: January 24, 1997
Creator: Soltz, R.A. & Collaboration, E910
Partner: UNT Libraries Government Documents Department

Analysis of nucleon-induced fission cross sections of lead and bismuth at energies from 45 to 500 MeV

Description: In order to investigate the applicability of the Cascade-Exciton model (CEM) of nuclear reactions to fission cross sections and hoping to learn more about intermediate-energy fission, the authors use an extended version of the CEM, as realized in the code CEM95 to perform a detailed analysis of proton- and neutron-induced fission cross sections of {sup 209}Bi and {sup 208}Pb nuclei and of the linear momentum transfer to the fissioning nuclei in the 45--500 meV energy range.
Date: August 1, 1998
Creator: Prokofyev, A.V.; Mashnik, S.G. & Sierk, A.J.
Partner: UNT Libraries Government Documents Department

Experimental device for measuring the momentum of disperse granular materials

Description: An experimental device for measuring the time averaged momentum associated with a steady stream of a disperse granular material has been developed. The mathematical basis for the device is presented including a discussion of using the momentum measurement to compute the local mass or energy fluxes. The analysis considers both nonuniform particle mass and nonuniform velocities for the various constituents of an aggregate material. The results of calibration experiments conducted with a prototype transducer are shown with theoretical predictions of these results.
Date: February 10, 1982
Creator: Watling, H.E. & Griffiths, S.K.
Partner: UNT Libraries Government Documents Department

NCI dichromatic beam tests

Description: The initial tests of the NCI dichromatic train showed that the momentum bite was within 2% of design. Though the data is by no means definitive, the particle fractions measured at 800 GeV are reasonably close to those predicted from 400 GeV data. A first look at the angular divergence of the beam showed it to be within 10% of design in the horizontal plane and about 35% greater than design in the vertical plane. Several problems were discovered which will be corrected before the next run.
Date: March 1, 1986
Creator: Stutte, L.
Partner: UNT Libraries Government Documents Department

Exact invariants in resonance form for time-dependent potentials

Description: We have developed a framework for the momentum-resonance formulation of Lewis and Leach that casts new light into the nature of exact, explicitly time-dependent invariants for one-dimensional time-dependent potentials and produces additional examples of such invariants. The momentum-resonance formulation postulates that the invariant be a rational function of momentum with simple poles, which are called momentum resonances. We have shown that an invariant of resonance type can be written as a functional of the potential in terms of the solution of a system of linear algebraic equations; and we have obtained a single necessary and sufficient condition for a potential to admit an invariant of resonance type. These results were obtained by reformulating the problem in terms of a set of discrete moments that satisfy two separate recursion formulae. Invariants for new time-dependent potentials were obtained and previously known invariants were recovered.
Date: January 1, 1985
Creator: Lewis, H.R. & Goedert, J.
Partner: UNT Libraries Government Documents Department

Summary of the working group 4: Hadron spectroscopy

Description: This report is a summary of the working group 4 on hadron spectroscopy. The topics covered are: physics motivation; design of spectrometer; status of some existing hadron spectrometers; improvements to LASS; and arguments for/against a LASS-like design.
Date: March 1, 1991
Creator: Crowe, K.M.
Partner: UNT Libraries Government Documents Department

Non-linear variation of the beta function with momentum

Description: A theory is presented for computing the non-linear dependence of the ..beta..-functions on momentum. Results are found for the quadratic term. The results of the theory are compared with computed results. A procedure is proposed for computing the strengths of the sextupole correctors to correct the dependence of the ..beta..-function on momentum.
Date: July 1, 1983
Creator: Parzen, G.
Partner: UNT Libraries Government Documents Department

The ring imaging Cerenkov detector for the BRAHMS experiment at RHIC

Description: A ring-imaging Cerenkov counter, to be read out by four 100-channel PMT`S, is a key element of the BRAHMS Experiment. We report here the most recent results obtained with a prototype tested at the BNL AGS using several radiator gases, including the heavy fluorocarbon C{sub 4}F{sub 10}. Ring radii were measured for different particles {pi}{sup {minus}}, {mu}{sup {minus}}, e{sup {minus}} for momenta ranging from 2 to 12 GeV/c employing pure C{sub 4}F{sub 10} as radiator.
Date: August 1, 1995
Creator: Debbe, R.; Gushue, S.; Moskowitz, B.; Olness, J. & Videbaek, F.
Partner: UNT Libraries Government Documents Department

Measurement of the polarization parameter for the reaction $pi$$sup - $p$Yields$$pi$$sup 0$n between 1.03 and 1.79 GeV/c

Description: From 2nd international conference on elementary particles; Aixen- Provence, France (6 Sep 1973). Measurements of the polarization parameter for the reaction pi /sup -/p yields pi /sup o/n were made at the five momenta 1.03, 1.245, 1.44, 1.5 and 1.79 GeV/c. A polarized target was used, with polarizations achieved ranging from 48 to 57%. Salient features of the experiment were the use of neutron counters for time-of-flight measurements as well as angular information and the use of optical spark chambers, seven to eight radiation lengths thick, for the detection of the gamma rays from the decay of the pi /sup o/. The center-ofmass angular range covered by the 20 neutron counters was typically --.78 < cos THETA /sub c.m. <.87. For each momentum there are approximately 10,000 events which fit pi /sup -/p yields pi /sup o/ n with a confide nce level of at least 10%. (auth)
Date: September 1, 1973
Creator: Shannon, S.R.; Anderson, L.; Bridgewater, A.; Chaffee, R.; Chamberlain, O.; Dahl, O. et al.
Partner: UNT Libraries Government Documents Department

An instrument for measuring the momentum flux from atomic and charged particle jets

Description: We have developed an instrument to measure the momentum flux from an intense plasma stream for which the standard techniques used for low pressure gases (<10 Torr) at room temperature are unsuitable. This device, a Plasma Momentum Meter, can measure forces of 10{sup {minus}5} {minus} 10{sup {minus}3} Newtons with a response time of <50 ms onto surfaces of different materials immersed in dense plasmas (n > 10{sup 12} cm{sup {minus}3}). Such forces are transmitted predominantly by ionic and neutral species, with 10's of eV's of kinetic energy, are accompanied by high heat fluxes, and are pulsed. The momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer, a capacitance-type pressure gauge. This protects the transducer from thermal damage, arcing and sputtering. An absolute force calibration of the PMM to 1% accuracy has been made is described. A flat carbon target has been used in measurements of the momentum flux of He, Ne, Ar, and Kr, plasmas produced in a magnetized linear plasma device. 7 refs., 7 figs.
Date: July 1, 1990
Creator: Cohen, S. A.; Zonca, F.; Timberlake, J.; Bennett, T.; Cuthbertson, J.; Langer, W. et al.
Partner: UNT Libraries Government Documents Department

Experimental observation of current generation by unidirectional electron plasma waves

Description: A slow wave structure was used to launch electron plasma waves traveling preferentially in one direction. The current generated by the waves was observed. The magnitude of the current can be estimated from momentum conservation in the wave-particle interaction process.
Date: August 1, 1978
Creator: Wong, K.L.
Partner: UNT Libraries Government Documents Department