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Partial Return Yoke for MICE

Description: The international Muon Ionization Cooling Experiment (MICE) is a large scale experiment which is presently assembled at the Rutherford Appleton Laboratory in Didcot, UK. The purpose of MICE is to demonstrate the concept of ionization cooling experimentally. Ionization cooling is an important accelerator concept which will be essential for future HEP experiments such as a potential Muon Collider or a Neutrino Factory. The MICE experiment will house up to 18 superconducting solenoids, all of which produce a substantial amount of magnetic flux. Recently it was realized that this magnetic flux leads to a considerable stray magnetic field in the MICE hall. This is a concern as technical equipment in the MICE hall may may be compromised by this. In July 2012 a concept called partial return yoke was presented to the MICE community, which reduces the stray field in the MICE hall to a safe level. This report summarizes the general concept, engineering considerations and the expected shielding performance.
Date: May 3, 2013
Creator: Witte, Holger & Plate, Stephen
Partner: UNT Libraries Government Documents Department

Shielding of External Magnetic Perturbations By Torque In Rotating Tokamak Plasmas

Description: The imposition of a nonaxisymmetric magnetic perturbation on a rotating tokamak plasma requires energy and toroidal torque. Fundamental electrodynamics implies that the torque is essentially limited and must be consistent with the external response of a plasma equilibrium ƒ = j x B. Here magnetic measurements on National Spherical Torus eXperiment (NSTX) device are used to derive the energy and the torque, and these empirical evaluations are compared with theoretical calculations based on perturbed scalar pressure equilibria ƒ = ∇p coupled with the theory of nonambipolar transport. The measurement and the theory are consistent within acceptable uncertainties, but can be largely inconsistent when the torque is comparable to the energy. This is expected since the currents associated with the torque are ignored in scalar pressure equilibria, but these currents tend to shield the perturbation.
Date: August 24, 2009
Creator: Jong-Kyu Park, Allen H. Boozer, Jonathan E. Menard, Stefan P. Gerhardt, and Steve A. Sabbagh
Partner: UNT Libraries Government Documents Department

Preliminary shielding estimates for the proposed National ISOL Radioactive Ion Beam (RIB) Facility at Oak Ridge

Description: ORNL built a first-generation Radioactive Ion Beam (RIB) facility for astrophysics and nuclear physics research; it was named Holifield Radioactive Ion Beam Facility (HRIBF) and is based on the Isotope Separator On Line (ISOL) technique. Planning is underway for a second- generation facility, the National ISOL RIB facility at Oak Ridge; it will build on the existing HRIBF and may utilize many existing components and shielded areas. Preliminary upgrade plan for the new facility includes: adding a superconducting booster for the tandem accelerator; replacing the 1960-vintage, 60-MeV proton, 50-microamp ORIC (Oak Ridge Isochronous Cyclotron) with a modern 200-MeV proton, 200-microamp cyclotron; and building a high-power {sup 238}U fission target to accept the 200-MeV proton beam. This report summarizes the results of a preliminary 1-D shielding analysis of the proposed upgrade, to determine the shielding requirements for a 0.25 mrem/h dose rate at the external surface of the exclusion area. Steel shielding weights ranging from 60 to 100 metric tons, were considered manageable; these could be reduced by a factor of 2 to 3 if the orientation of the proposed target station was changed.
Date: October 1, 1996
Creator: Johnson, J.O.; Gabriel, T.A. & Lillie, R.A.
Partner: UNT Libraries Government Documents Department

Beam collimation and shielding in the Fermilab proton driver

Description: A high beam power in the proposed Fermilab Proton Drivers--1.2 MW in 16-GeV PD-I and 0.48 MW in 8-GeV PD-II--implies serious constraints on beam losses in these machines. Only with a very efficient beam collimation system can one reduce uncontrolled beam losses in the machine to an allowable level. The entire complex must be well shielded to allow acceptable hands-on maintenance conditions in the tunnel and a non-controlled access to the outside shielding at normal operation and accidental beam loss. Collimation and shielding performances are calculated and compared for both Proton Drivers.
Date: June 28, 2002
Creator: Mokhov, Alexandr I. Drozhdin and Nikolai V.
Partner: UNT Libraries Government Documents Department

Military Field Expedient Shielding Experiment

Description: Convair-Fort Worth, under contract to the U.S. Army Engineer Research and Development Laboratories, performed experiments to obtain data for use in applying field materials to shield portable nuclear-reactor power plants.
Date: October 18, 1960
Creator: Wheeler, D. M. & Bostick, L. H.
Partner: UNT Libraries Government Documents Department

Test Results on D-12A-2

Description: The purpose of this report is to describe the recent tests of D-12A-2. The tests of D-12A-2 began on April 30 and ended on May 8. The unusually long test period was a result of an extensive series of magnetic field measurements in which we attempted to determine the shielding affects of a sextupole compensating coil and the decay of the currents induced in this coil. This report is short, but much of the data from the tests are included or summarized. We begin with a description of the coil and conductor, continue with the training history, the results of magnetic measurements, including the use of a sextupole compensating coil and then describe the results of heater induced quenches including estimates of axial and transverse quench propagation velocities.
Date: August 8, 1984
Creator: Hassenzahl, W.
Partner: UNT Libraries Government Documents Department

Source Strength Information for Shielding and Stack Effluent Calculations: a Standard Practices Guide

Description: Report presenting the curves and methods used "for determining gross fission product gamma energy in Mev/sec-watt, gross fission product beta decay in curies/sec-watt, delayed uranium fission neutrons in neutrons/sec-watt and N16 and N17 decay in photons/sec-cc of water" (p. 1).
Date: October 3, 1958
Creator: Jones, L. H.
Partner: UNT Libraries Government Documents Department

A Study of Techniques for Measuring the Electromagnetic Shielding Effectiveness of Materials

Description: Abstract: Shielding effectiveness relates to a material's ability to reduce the transmission of propagating fields in order to electromagnetically isolate one region from another. Because a complex material's shielding capability is difficult to predict, it often must be measured. A number of measurement approaches are studied including the use of a shielded room, coaxial transmission line holders, time domain signals, the dual TEM cell, and an apertured TEM cell in a reverberation chamber. In each case, we consider the system's frequency range, test sample requirements, test field type, dynamic range, time required, analytical background, and present data taken on a common set of materials.
Date: May 1986
Creator: Wilson, Perry F. & Ma, Mark T.
Partner: UNT Libraries Government Documents Department

Method for processing ENDF/B photon form factor data

Description: A method is described for processing ENDF/B photon data to generate group-to-group scattering matrices. The method has these salient features: 1. It is tailored toward treating the full energy and angular detail with which the cross sections are represented in ENDF/B; 2. It is simple to program; 3. It closely parallels a treatment developed for producing multigroup neutron matrices; 4. The time required to execute the method on a computer varies linearly with the number of energy groups as opposed to double numerical integration schemes which tend to vary as the square of the number of groups. (GHT)
Date: January 1, 1975
Creator: Lucius, J.L. & Greene, N.M.
Partner: UNT Libraries Government Documents Department


Description: Digital-computer shielding-nuclear analysis programs are described. Each description includes (1) the purpose of the program, (2) the theoretical or physical assumptions, and (3) the major computer equipment required by the program. (auth)
Date: October 29, 1957
Creator: Capo, M.A.
Partner: UNT Libraries Government Documents Department