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Use of an elliptical aperture to control saturation in closely-coupled, cold iron, superconducting dipole magnets

Description: The high fields permitted by superconducting windings result in saturation of closely-coupled iron in dipole and quadrupole beam transport magnets. Coupland suggested using a triangular cutout at the poles to reduce the change in the sextupole (b/sub 2/) term due to saturation. The use of an elliptical aperture in a close-coupled dipole for the Relativistic Heavy Ion Collider (RHIC) has been studied using the BNL computer program MDP (a version of GFUN). The ellipse aspect ratio was varied while holding the horizontal (minor) radius constant. The proper aspect ratio gives no shift in b/sub 2/ sue to saturation, and a reduction in the b/sub 4/ shift. A modification of the ellipse also reduces b/sub 4/. The elliptical aperture introduces a large b/sub 2/ term at low field which must be compensated for by the coil design. A practical coil design which does this for the RHIC magnet is presented. 5 refs., 2 figs., 3 tabs.
Date: January 1, 1985
Creator: Morgan, G.
Partner: UNT Libraries Government Documents Department

Reduction of iron saturation in cosine theta dipoles

Description: A procedure is presented for systematically perturbing the circular iron aperture of a cosine-theta dipole in such a way as to postpone saturation effects up to the point where insufficient iron is present on the midplane. The resulting configuration has little loss in field compared to the alternative procedure of putting a large annulus between the coils and the iron. The necessary saturable iron program used was MDP, but the procedure could be performed with any program. The perturbation functions used to modify the iron shape provide good separation of effects so that only one perturbation per harmonic is needed, thus minimizing the amount of computation required. A coil and aperture configuration with low-field harmonic content approaching the stringent RHIC requirements is presented which requires no b/sub 4/ or higher order correction coils up to 4.1 T, with a good field aperture at low field of 32 mm and at 4.1 T, 30 mm. The b/sub 2/ correction required is largest at an intermediate field, and has a maximum amplitude of about -3.2. The transfer function of the configuration is about 2% higher than that of the reference design.
Date: January 1, 1986
Creator: Morgan, G.
Partner: UNT Libraries Government Documents Department

Cross sections for the /sup 7/Li(n,xn) and /sup 7/Li(n,n'. gamma. ) reactions between 1 and 20 MeV

Description: Differential cross sections for the production of secondary neutrons and gamma rays from neutron interactions in /sup 7/Li have been measured at 50/sup 0/ and 126/sup 0/ (lab) for incident neutron energies in the range 1 to 20 MeV. An electron linac was used as a white neutron source. Incident neutron energies were determined using time-of-flight techniques for a source-to-sample distance of 48 m. Secondary spectra were determined by analysis of the pulse-height distributions observed in a NE-213 scintillation counter. The results are compared to the current evaluated data file (ENDF/B-IV, MAT 1272).
Date: March 1, 1978
Creator: Morgan, G.L.
Partner: UNT Libraries Government Documents Department

Cross sections for the Cu(n,xn) and Cu(n,x. gamma. ) reactions between 1 and 20 MeV

Description: Differential cross sections for the production of secondary neutrons and gamma rays from neutron interactions in natural copper have been measured at 130/sup 0/ (lab) for incident neutron energies in the range 1 to 20 MeV. An electron linac was used as a pulsed, white neutron source. Incident neutron energies were determined using time-of-flight techniques for a source-to-sample distance of 48 m. Secondary spectra were determined by unfolding the pulse-height distributions observed in a NE-213 scintillation counter. The results are compared to the current evaluated nuclear data file (ENDF/B-IV, MAT 1295).
Date: February 1, 1979
Creator: Morgan, G.L.
Partner: UNT Libraries Government Documents Department

Cross sections for the Ti(n,xn) and Ti(n,x. gamma. ) reactions between 1 and 20 MeV. [1 to 20 MeV, differential cross sections]

Description: Differential cross sections for the production of secondary neutrons and gamma rays from neutron interactions in natural titanium were measured at 130 deg. (lab) for incident neutron energies in the range 1 to 20 MeV. An electron linac was used as a pulsed, white neutron source. Incident neutron energies were determined using time-of-flight techniques for a source-to-sample distance of 48 m. Secondary spectra were determined by unfolding the pulse-height distributions observed in a NE-213 scintillation counter. The results are compared to the current evaluated nuclear data file (ENDF/B-IV, MAT 1286). 23 references.
Date: August 1, 1979
Creator: Morgan, G.L.
Partner: UNT Libraries Government Documents Department

Optimization of multiwire coil ends having 45 degree bends

Description: Multiwire is the name of a proprietary process for affixing small diameter wires to a flat substrate using digitally controlled machinery. It is currently being used to wind trim coils for the SSC dipoles on a flexible substrate which is wrapped around the beam tube. It is proposed for making multipole coils for the Corrector, a regular arc magnet in each half-cell of the Relativistic Heavy Ion Collider (RHIC). The current Multiwire process does not permit a change in direction of the wire other than 45 degree. The present paper answers the question of whether the 45 degree bends in the flattened coil can be located along straight lines in such a way as to eliminate or reduce higher harmonics in the ends. The more general question of bends located along curves is not addressed. 3 refs., 3 figs., 2 tabs.
Date: January 1, 1988
Creator: Morgan, G.H.
Partner: UNT Libraries Government Documents Department

EFFECT OF IMPURITIES ON THE PERFORMANCE OF A Pd-Ag DIFFUSER

Description: A commercially fabricated diffuser purchased from Johnson-Matthey, Inc. was evaluated for performance characterization testing at the Savannah River National Laboratory (SRNL). Different impurities are often present in the feed streams of the process diffusers, but the effect of these impurities on the diffuser performance is currently unknown. Various impurities were introduced into the feed stream of the diffuser at various levels ranging from 0.5% to 10% of the total flow in order to determine the effect that these impurities have on the permeation of hydrogen through the palladium-silver membrane. The introduction of various impurities into the feed stream of the diffuser had a minimal effect on the overall permeation of hydrogen through the Pd-Ag membrane. Of the four impurities introduced into the feed stream, carbon monoxide (CO) was the only impurity that showed any evidence of causing a reduction in the amount of hydrogen permeating through the Pd-Ag membrane. The hydrogen permeation returned to its baseline level after the CO was removed from the feed stream. There were no lasting effects of the CO exposure on the ability of the membrane to effectively separate hydrogen from the non-hydrogen species in the gas stream under the conditions tested.
Date: December 16, 2010
Creator: Morgan, G.
Partner: UNT Libraries Government Documents Department

Cross sections for the Al(n,xn) and Al(n,x$gamma$) reaction between 1 and 20 MeV

Description: Differential cross sections for the production of secondary neutrons and photons from aluminum have been measured at 127$sup 0$ (lab) for incident neutron energies in the range 1 to 20 MeV. An electron linac was used as a neutron source with a white spectrum. Incident neutron energies were determined using time-of-flight techniques for a source-to-sample distance of 48 m. Secondary spectra were determined by unfolding the pulse-height distributions observed in a NE-213 scintillation counter. The results are compared to the current evaluated data file (ENDF/B-IV, MAT 1193). (auth)
Date: January 1, 1976
Creator: Morgan, G.L. & Perey, F.G.
Partner: UNT Libraries Government Documents Department

Integral experiments for fusion reactor design: experimentation

Description: Integral experiments that measure the energy spectra of neutrons and gamma rays due to the transport of approx. 14-MeV T(d,n)/sup 4/He neutrons through thick steel and borated polyethylene shield configurations have been performed at the Oak Ridge National Laboratory. Descriptions of the facility and experimental techniques are given along with curves showing data representative of the results.
Date: January 1, 1979
Creator: Chapman, G.T. & Morgan, G.L.
Partner: UNT Libraries Government Documents Department

O(n,x. gamma. ) reaction cross section for incident neutron energies between 6. 5 and 20. 0 MeV. [Yield]

Description: Differential cross sections for the neutron-induced gamma-ray production from oxygen were measured for incident neutron energies between 6.5 and 20.0 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons and a NaI spectrometer to detect the gamma rays at 125/sup 0/. The data presented are the double differential cross section, d/sup 2/sigma/d..cap omega..dE, for gamma-ray energies between 1.6 and 10.6 MeV for coarse intervals in incident neutron energy. The integrated yield for gamma rays of energies greater than 1.6 MeV with higher resolution in the neutron energy is also presented. The experimental results are compared with the Evaluated Nuclear Data File (ENDF). 34 references.
Date: September 1, 1979
Creator: Morgan, G.L. & Chapman, G.T.
Partner: UNT Libraries Government Documents Department

Collarless, close-in, shaped iron aperture designs for the SSC (Superconducting Super Collider) dipole

Description: The nominal-design SSC (Superconducting Super Collider) dipole encloses the coil in an iron yoke having a circular aperture. The radial gap between the coil and the iron is about 15 mm to provide space for a strong annular collar around the coil, and also to reduce the effects of iron saturation on central field harmonics. The 15 mm gap also reduces the desirable dipole field contributed by the iron. The present paper gives a coil and aperture configuration in which the gap is reduced to 5 mm at the midplane, in which the aperture is shaped to reduce the unwanted effects of iron saturation. The transfer function is increased about 5% at 6.6 Tesla and the unwanted harmonics are within SSC tolerances at all field levels. These designs would require that the yoke and containment vessel absorb the stresses due to assembly and magnetic forces. A short magnet is being built with a close-in shaped iron aperture and existing coil geometry to assess the benefits of this concept. 7 refs., 3 figs., 6 tabs.
Date: January 1, 1989
Creator: Gupta, R.C. & Morgan, G.H.
Partner: UNT Libraries Government Documents Department

Design for a high field combined function superferric magnet

Description: A combined function superferric magnet option has been investigated for the Relativistic Heavy Ion Collider (RHIC). The option requires the maximum value of the field in the magnet to be much higher than that achieved in any existing combined function accelerator magnet. A model is presented here in which a good field quality can be maintained up to 2T. It is done by carefully designing the yoke structure and positioning the coils in such a way that the iron poles tend to saturate evenly across the gap. A cold iron model might be necessary for this magnet. 4 refs., 2 figs., 1 tab.
Date: January 1, 1985
Creator: Gupta, R.C. & Morgan, G.H.
Partner: UNT Libraries Government Documents Department

A computer program for the 2-D magnetostatic problem based on integral equations for the field of the conductors and boundary elements

Description: The iterative design of the 2-dimensional cross section of a beam transport magnet having infinitely permeable iron boundaries requires a fast means of computing the field of the conductors. Solutions in the form of series expansions are used for rectangular iron boundaries, and programs based on the method of images are used to simulate circular iron boundaries. A single procedure or program for dealing with an arbitrary iron boundary would be useful. The present program has been tested with rectangular and circular iron boundaries and provision has been made for the use of other curves. It uses complex contour integral equations for the field of the constant-current density conductors and complex line integrals for the field of the piecewise-linear boundary elements. 2 refs., 4 figs., 1 tab.
Date: January 1, 1991
Creator: Morgan, G.H.
Partner: UNT Libraries Government Documents Department

Ti(n,x. gamma. ) reaction cross section for incident neutron energies between 0. 3 and 20. 0 MeV

Description: Differential cross sections for the neutron-induced gamma-ray production from natural titanium were measured for incident neutron energies between 0.3 and 20.0 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons, and a NaI spectrometer, to detect the gamma rays at 125/sup 0/. The data presented are the double differential cross section, d/sup 2/sigma/d..cap omega..dE, for gamma-ray energies between 0.3 and 10.6 MeV for coarse intervals in incident neutron energy. The integrated yield of gamma rays of energies greater than 300 keV with higher resolution in the neutron energy is also presented. The experimental results are compared with the Evaluated Nuclear Data Files (ENDF). 22 figures, 20 tables.
Date: June 1, 1978
Creator: Morgan, G.L. & Larson, D.C.
Partner: UNT Libraries Government Documents Department

Field flattening in superconducting beam transport magnets

Description: Dipoles in which the beam traverses the midplane well away from tie magnet axis may benefit from flattening of the vertical field on the midplane. A procedure is described for doing so, making use of Chebyshev polynomials. In the case of the large aperture ``DX`` magnets located immediately on each side of the six intersection regions of the Relativistic Heavy Ion Powder (RHIC), a comparison is made of the field of coils optimized in this way and of coils optimized in the more common way by minimizing the leading coefficients of the Fourier expansion about the magnet axis. The comparison is of the integrated Fourier coefficients of the field expanded locally along the beam trajectory.
Date: December 31, 1994
Creator: Morgan, G. H.
Partner: UNT Libraries Government Documents Department

THE ABSORPTION OF HYDROGEN ON LOW PRESSURE HYDRIDE MATERIALS

Description: For this study, hydrogen getter materials (Zircaloy-4 and pure zirconium) that have a high affinity for hydrogen (and low overpressure) have been investigated to determine the hydrogen equilibrium pressure on Zircaloy-4 and pure zirconium. These materials, as with most getter materials, offered significant challenges to overcome given the low hydrogen equilibrium pressure for the temperature range of interest. Hydrogen-zirconium data exists for pure zirconium at 500 C and the corresponding hydrogen overpressure is roughly 0.01 torr. This manuscript presents the results of the equilibrium pressures for the absorption and desorption of hydrogen on zirconium materials at temperatures ranging from 400 C to 600 C. The equilibrium pressures in this temperature region range from 150 mtorr at 600 C to less than 0.1 mtorr at 400 C. It has been shown that the Zircaloy-4 and zirconium samples are extremely prone to surface oxidation prior to and during heating. This oxidation precludes the hydrogen uptake, and therefore samples must be heated under a minimum vacuum of 5 x 10{sup -6} torr. In addition, the Zircaloy-4 samples should be heated at a sufficiently low rate to maintain the system pressure below 0.5 mtorr since an increase in pressure above 0.5 mtorr could possibly hinder the H{sub 2} absorption kinetics due to surface contamination. The results of this study and the details of the testing protocol will be discussed.
Date: April 3, 2012
Creator: Morgan, G. & Korinko, P.
Partner: UNT Libraries Government Documents Department

TMED-4 INTERIM REPORT PURE ZR EQUILIBRIUM TEST RESULTS

Description: Due to higher than expected permeation rates in the production of tritium in the TVA, a development and testing program was implemented to develop the understanding of why the higher rates were occurring. In addition, improved data are needed for both the design as well as the predictive models. One part of the program was to determine the equilibrium pressure of hydrogen and tritium over NPZ (1). During the course of this testing, some curious results were discovered (2) compared to the published literature data (3). Due to these apparently results, a follow-on task was undertaken to determine the equilibrium pressure of protium and deuterium over pure zirconium. A series of experiments were conducted to determine equilibrium pressures and isotherm data for the zirconium - protium and zirconium - deuterium systems. The data match the published literature data reasonably well with the plateau extending to loadings of about 1.4. There is a significant pressure rise for loadings greater than 1.7.
Date: December 17, 2010
Creator: Korinko, P. & Morgan, G.
Partner: UNT Libraries Government Documents Department