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The Deflection of Charged Particles in an Electric Dodecapole Field

Description: The properties of an ion-optical device consisting of twelve long parallel rods placed equidistantly on a circle are briefly reviewed. The use of this device in its dodecapole configuration to deflect ions in a plane perpendicular to the axis of the dodecapole is discussed. Results of trajectory computations made with the SIMION ion-optics computer program demonstrate that the device works remarkably well in separating the constituents of a multiply-charged ion beam. The use of this device to m… more
Date: October 10, 1997
Creator: Seely, D. G.; Chalut, K.; Thompson, J. S. & Kvale, T. J.
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Partner: UNT Libraries Government Documents Department
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Multiwire proportional chambers in M1 and M3 spectrometers of charmed baryon experiment (E781) at Fermilab

Description: The status of the multiwire proportional chambers in the FERMILAB E781 experiment and a general description of the readout system are given. This essay will describe the system of multiwire proportional chambers (MWPC) that are part of the Fermilab experiment E781 setup. Multiwire proportional chambers are often used in particle physics experiments because they can determine the position of charged particles very accurately (less than a millimeter). The E781 experiment which is also called SELE… more
Date: August 1, 1997
Creator: Kaya, Mithat
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Kinetic description of intense nonneutral beam propagation through a periodic solenoidal focusing field based on the nonlinear Vlasov-Maxwell equations

Description: A kinetic description of intense nonneutral beam propagation through a periodic solenoidal focusing field B{sup sol}({rvec x}) is developed. The analysis is carried out for a thin beam with characteristic beam radius r{sub b} {much_lt} S, and directed axial momentum {gamma}{sub b}m{beta}{sub b}c (in the z-direction) large compared with the transverse momentum and axial momentum spread of the beam particles. Making use of the nonlinear Vlasov-Maxwell equations for general distribution function f… more
Date: August 1, 1997
Creator: Davidson, R.C. & Chen, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Relativistic charged particle in the dipole-sphere configuration I. Classical and semiclassical surface orbits

Description: The classical and semiclassical orbits of a relativistic charged particle on a rotating sphere threaded by a magnetic dipole field are examined. The rotational and dipole axes are in general not aligned. Several physically distinct regimes emerge, depending on the relative sizes of the total energy, canonical azimuthal angular momentum, and magnetic field strength. Magnetic flux enclosed by orbits is quantised very close to the poles. Application of this system to neutron star magnetic fields a… more
Date: January 1, 1997
Creator: Gopinath, K.S.; Kennedy, D.C. & Gelb, J.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Statistically-averaged rate equations for intense nonneutral beam propagation through a periodic solenoidal focusing field based on the nonlinear Vlasov-Maxwell equations

Description: This paper presents a detailed formulation and analysis of the rate equations for statistically-averaged quantities for an intense nonneutral beam propagating through a periodic solenoidal focusing field B{sup sol}(x). The analysis is based on the nonlinear Vlasov-Maxwell equations in the electrostatic approximation, assuming a thin beam with characteristic beam radius r{sub b} {much_lt} S. The results are applied to investigate the nonlinear evolution of the generalized entropy, mean canonical… more
Date: August 1, 1997
Creator: Davidson, R. C.; Lee, W. W. & Stoltz, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Charged particles produced in neutron reactions on nuclei from beryllium to gold

Description: Charged-particle production in reactions of neutrons with nuclei has been studied over the past several years with the spallation source of neutrons from 1 to 50 MeV at the Los Alamos Neutron Science Center (LANSCE). Target nuclides include 9Be, C, 27Al, Si, 56Fe, 59Co, 58,60Ni, 93Nb and 197Au. Proton, deuteron, triton, 3He and 4He emission spectra, angular distributions and production cross sections have been measured. Transitions from the compound nuclear reaction mechanism to precompound rea… more
Date: August 1, 1997
Creator: Haight, R. C.
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Partner: UNT Libraries Government Documents Department
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Kinetic theory of plasma adiabatic major radius compression in tokamaks

Description: A kinetic approach is developed to understand the individual charged particle behavior as well as plasma macro parameters (temperature, density, etc.) during the adiabatic R-compression in a tokamak. The perpendicular electric field from Ohm`s law at zero resistivity E = {minus}v{sub E} x B/c is made use of to obtain the equation for particle velocity evolution in order to describe the particle motion during the R-compression. Expressions for both passing and trapped particle energy and pitch a… more
Date: October 1, 1997
Creator: Gorelenkova, M. V.; Gorelenkov, N. N.; Azizov, E. A.; Romannikov, A. N. & Herrmann, H. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Intense nonneutral beam propagation in a periodic solenoidal field using a macroscopic fluid model with zero thermal emittance

Description: A macroscopic fluid model is developed to describe the nonlinear dynamics and collective processes in an intense high-current beam propagating in the z-direction through a periodic focusing solenoidal field B{sub z}(z + S) = B{sub z}(z), where S is the axial periodicity length. The analysis assumes that space-charge effects dominate the effects of thermal beam emittance, Kr{sub b}{sup 2} {much_gt} {epsilon}{sub th}{sup 2}, and is based on the macroscopic moment-Maxwell equations, truncated by n… more
Date: August 1, 1997
Creator: Davidson, R. C.; Stoltz, P. & Chen, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Particle acceleration from reconnection in the geomagnetic tail

Description: Acceleration of charged particles in the near geomagnetic tail, associated with a dynamic magnetic reconnection process, was investigated by a combined effort of data analysis, using Los Alamos data from geosynchronous orbit, MHD modeling of the dynamic evolution of the magnetotail, and test particle tracing in the electric and magnetic fields obtained from the MHD simulation.
Date: August 1, 1997
Creator: Birn, J.; Borovsky, J. E.; Thomsen, M. F.; McComas, D. J.; Reeves, G. D.; Belian, R.D. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An Efficient Method for Heavy Ion Dose Calculations

Description: Heavy charged particles deposit much of their kinetic energy at very high rates in small volumes near the end of their range. This characteristic, coupled with the availability of modern particle accelerators, has sparked a revival of interest in the use of ions as a possible treatment tool for certain types of cancers. Collisions between projectile ions and atoms in the target medium can result in ion fragments that are different from the original projectile species. The energy deposition char… more
Date: June 1997
Creator: Dandini, Vincent J. & Prinja, Anil K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Relativistic charged particle in magnetic dipole-spherical geometry. III. Local three-dimensional states

Description: Following two previous papers, we examine single- and many-body states of relativistic charged particles in an intense, rotating magnetic dipole field. Single-body orbits are derived classically and semiclassically, and then applied to the many-body orbits are derived classically and semiclassically, and then applied to the many-body case via the Thomas-Fermi approximation. Examples of electrons in a realistic neutron star crust are considered with both fixed density profiles and constant Fermi… more
Date: July 1, 1997
Creator: Gopinath, K.S.; Kennedy, D.C. & Gelb, J.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Charge collection and SEU from angled ion strikes

Description: Single event upsets (SEUs) are caused in semiconductor microcircuits when charge is deposited in a sensitive volume of the circuit by an incident energetic particle. Collection of this charge causes a loss of information stored at the struck circuit node. Sensitive regions of a microcircuit typically consist of reverse-biased junctions which efficiently collect deposited charge through the influence of drift fields. During laboratory SEU testing, angled ion strikes are often used to convenientl… more
Date: March 1, 1997
Creator: Dodd, P. E.; Shaneyfelt, M. R. & Sexton, F. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Relativistic charged particle in the dipole-sphere configuration. II. General tilted surface orbits.

Description: Relativistic charged particle orbits on a rotating sphere threaded by an intense magnetic dipole field are examined. Generalizing the results of the first paper (I), the dipole and rotational axes have arbitrary relative tilt. For ultra-intense magnetic fields characteristic of compact astrophysical bodies, the classical and semiclassical results are not greatly changed for moderate rotation rates. 4 refs., 4 figs.
Date: March 1, 1997
Creator: Gopinath, K.S. & Kennedy, D.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation and Prediction of RF Window Performance in APT Accelerators

Description: The work described in this report was performed between November 1996 and May 1997 in support of the APT (Accelerator Production of Tritium) Program at Los Alamos National Laboratory. The goal was to write and to test computer programs for charged particle orbits in RF fields. The well-documented programs were written in portable form and compiled for standard personal computers for easy distribution to LANL researchers. They will be used in several APT applications including the following. Min… more
Date: May 1, 1997
Creator: Humphries, S., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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