6 Matching Results

Search Results

Advanced search parameters have been applied.

Restoration and testing of an HTS fault current controller

Description: A three-phase, 1200 A, 12.5 kV fault current controller using three HTS 4 mH coils, was built by industry and tested in 1999 at the Center Substation of Southern California Edison in Norwalk, CA. During the testing, it appeared that each of the three single-phase units had experienced a voltage breakdown, one externally and two internally. Los Alamos National Laboratory (LANL) was asked by DOE to restore the operation of the fault current controller provided the HTS coils had not been damaged during the initial substation tests. When the internally-failed coil vacuum vessels were opened it became evident that in these two vessels, a flashover had occurred at the high voltage bus section leading to the terminals of the superconducting coil. An investigation into the failure mechanism resulted in six possible causes for the flashover. Based on these causes, the high voltage bus was completely redesigned. Single-phase tests were successfully performed on the modified unit at a 13.7 kV LANL substation. This paper presents the postulated voltage flashover failure mechanisms, the new high voltage bus design which mitigates the failure mechanisms, the sequence of tests used to validate the new design, and finally, the results of variable load and short-circuit tests with the single-phase unit operating on the LANL 13.7 kV substation.
Date: January 1, 2002
Creator: Waynert, J. A. (Joseph A.); Boenig, H. (Heinrich E.); Mielke, C. H. (Charles H.); Willis, J. O. (Jeffrey O.) & Burley, B. L. (Burt L.)
Partner: UNT Libraries Government Documents Department

Experimental heat leak measurements on the APT 210 KW CW RF power coupler

Description: A cryogenic test rig was designed and fabricated to measure the heat leak from room temperature to 2 K from the Accelerator Production of Tritium (APT) 700 MHz, 210 kW continuous wave (CW) co-axial power coupler (PC). The outer conductor of the PC is stainless steel with 15 {micro}m copper film on the inside. The copper inner conductor operates at room temperature and contributes considerable infra-red radiation heat load to 2 K. Two thermal intercept heat exchangers cooled by supercritical helium are incorporated into the outer conductor to reduce the heat conducted to the lowest temperatures. A brief description of the experimental apparatus is presented. A comparison of the experimental measurements and the predictions of a detailed thermal model is given. There is also a discussion of anomalous behavior observed in the thermal intercepts, and fluctuations in the helium coolant properties.
Date: January 1, 2001
Creator: Blumenfelda, P. E.; Prenger, F. Coyne; Kelley, J. P. (John Patrick); Currie, S. A. (Scott A.); Stewart, J. A. (James A.) & Waynert, J. A. (Joseph A.)
Partner: UNT Libraries Government Documents Department

Advanced Hydrotest Facility (AHF) large bore quadrupole focusing magnet system

Description: The Advanced Hydrotest Facility (AHF) at Los Alamos will provide proton radiography of large-scale, dynamic events. The large bore (Case II) quadrupole focusing magnets are a subsystem in this facility, consisting of four complete imaging lines with a total of eight imaging plates and 52 quadrupole magnets. Each large bore quadrupole has an inner winding diameter of 660 mm and provides a gradient of 10.4 T/m with a 300 mm field of view. Each magnet is a two-layer saddle, contained by a three cm steel shell. The conductor is a Rutherford cable, soldered into a C-shaped copper channel. The magnets are cooled by the forced-flow of two-phase helium through coolant pipes. Since the winding must absorb bursts of 0.35 J/kg irradiation, both NbTi and Nb{sub 3}Sn designs are being considered.
Date: January 1, 2002
Creator: Jason, A. J. (Andrew J.); Walstrom, P. L. (Peter L.); Waynert, J. A. (Joseph A.); Schultz, J. (Joel); Camille, R. J.; Antaya, T. (Thomas) et al.
Partner: UNT Libraries Government Documents Department

Beam-distribution system for multi-axis imaging at the Advanced Hydrotest Facility

Description: The Advanced Hydrotest Facility is to provide a time sequence of multiple radiographic images using a proton beam produced by a 50-GeV synchrotron. We give an overview of the approaches devised to produce up to twelve simultaneous radiographic images of an object by a sequence of beam-transport lines. The required distribution system has undergone a parametric study that optimizes its configuration within operational constraints. These constraints and our approach to configuration optimization for both superconducting and normal-conducting transport lines are described. Additionally, we describe the optics stratagems that were devised to meet system requirements.
Date: January 1, 2001
Creator: Jason, A. J. (Andrew J.); Barlow, D. B. (David B.); Blind, B. (Barbara); Kelley, J. P. (John Patrick); Lysenko, W. P. (Walter P.); Mottershead, C. T. et al.
Partner: UNT Libraries Government Documents Department

Results of the APT RF power coupler development for superconducting linacs.

Description: For the new baseline APT (Accelerator Production of Tritium) linac design, the power couplers are required to transmit 420 kW of CW RF power to the superconducting cavities at 700 MHz. These couplers consist of an airside waveguide-to-coax transition, an air/vacuum break made by two planar, coaxial windows, and a vacuum-side coaxial antenna section. The coaxial antenna allows adjustability of the RF matching to the superconducting cavities. Design, fabrication, and testing of the power coupler/window occurred over the last four years, and room temperature testing of the prototype design is complete. Coupler/window assemblies have transmitted power to 1 MW, CW and have handled full reflected 850 kW, CW over a limited standing-wave phase range. Couplers were tested with a portion of the outer conductor cooled by liquid nitrogen to study the effects of condensed gases. No hard multipacting barriers were encountered during any of this room temperature testing. Final results, conclusions, and lessons learned about the coupler design, fabrication, and testing will be discussed.
Date: January 1, 2001
Creator: Schmierer, E. N. (Eric N.); Haynes, W. B. (William B.); Krawczyk, F. L. (Frank L.); Gautier, D. C. (Donald Cort); Gioia, J. G. (Jack G.); Madrid, M. A. (Michael A.) et al.
Partner: UNT Libraries Government Documents Department

ADPF spoke cavity cryomodule concept

Description: The Accelerator Driven Test Facility (ADTF) is being developed as a reactor concepts test bed for transmutation of nuclear waste. A 13.3 mA continuous-wave (CW) proton beam will be accelerated to 600 MeV and impinged on a spallation target. The subsequent neutron shower is used to create a nuclear reaction within a subcritical assembly of waste material that reduces the waste half-life from the order of 10{sup 5} years to 10{sup 2} years. Additionally, significant energy is produced that can be used to generate electrical power. The ADTF proton accelerator consists of room-temperature (RT) structures that accelerate the beam to 6.7-MeV and superconducting (SC) elements that boost the beam's energy to 600-MeV. Traditional SC elliptical cavities experience structural difficulties at low energies due to their geometry. Therefore, stiff-structured SC spoke cavities have been adopted for the energy range between 6.7 and 109 MeV. Elliptical cavities are used at the higher energies. This paper describes a multi-spoke-cavity cryomodule concept for ADTF.
Date: January 1, 2001
Creator: Kelley, J. P. (John Patrick); Roybal, P. L. (Phillip L.); La Fave, R. P. (Richard P.); Waynert, J. A. (Joseph A.); Schrage, D. L. (Dale L.); Schmierer, E. N. (Eric N.) et al.
Partner: UNT Libraries Government Documents Department