Magnetized Target Fusion (MTF) is a means to compress plasmas to fusion conditions that uses magnetic fields to greatly reduce electron thermal conduction, thereby greatly reducing compression power density requirements (1,2). The compression is achieved by imploding the boundary, a metal shell. This effort pursues formation of the Field Reversed Configuration (FRC) type of magnetized plasma, and implosion of the metal shell by means of magnetic pressure from a high current flowing through the shell. We reported at Megagauss 9 that we had shown experimentally (3) that we can use magnetic pressure from high current capacitor discharges to implode long cylindrical metal shells (liners) with size, symmetry, implosion velocity, and overall performance that is suitable for compression of Field Reversed Configurations (FRC's). We also presented considerations of using deformable liner ¿ electrode contacts of Z-pinch geometry liners or theta pinch driven liners, in order to have axial access to inject FRC's and to have axial diagnostic access. Since then, we have experimentally implemented the Z-pinch discharge driven deformable liner ¿ electrode contact, obtained full axial coverage radiography of such a liner implosion, and obtained 2D-MHD simulations for a variety of profiled thickness long cylindrical liners. The radiographic results indicate that at least 16 times radial compression of the inner surface of a 0.11 cm thick Al liner was achieved, with a symmetric implosion free of instability growth. We have also made progress in combining 2D-MHD simulations of FRC formation with imploding liner compression of FRC's.

Study Objectives: Patients that present to the ED seeking treatment and then leave without being seen represent lost revenue, a liability risk, negative public relations, and deferred care for the patient. Reasons for the patient leaving often are beyond our control but there are processes that can potentially impact the “Left without treatment” (LWT) rate. Previous investigations have demonstrated that patients are more likely to leave as their wait increases or if they have other obligations. They are more inclined to stay as the length of wait time is reduced. Our ED leadership hypothesized that in-room registration would improve patient flow and through-put times. As a corollary we conducted a pre and post implementation analysis to assess the outcome this would have on patients leaving without treatment.

The design and test results of a crowbar switch developed for the formation of long-lifetime field-reversed configurations are presented. These research efforts are being pursued at the FRX-L facility at Los Alamos National Laboratory using the "Colt" capacitor bank (a 36 muF Shiva Star bank module capable of storing up to 250 U) and at the Air Force Research Laboratory using the "Formation" capacitor bank (consisting of three parallel banks identical to Colt). The crowbar switch design includes four Maxwell rail-gap switches mounted on a cable header that transitions from the capacitor bank bus plates to 48 RG 17/14 coaxial cables. For the testing performed at AFRL, a dummy load was set up to simulate the magnetic field coils of the actual experiment. Tests thus far have demonstrated the crowbarring of peak currents up to 1.25 MA. Breakdown within the cable header due to the initial high voltage applied from the bank has been successfully suppressed by the cable feed-through design, proper placement of Mylar sheets around the switch for insulation, and replacement of air in the header with SF6. Timing for the triggering of the crowbar is somewhat critical, as inductance in the switch increases when the switch is triggered with lower voltages across the switch rails. At the higher bank charge voltages, the charge-flow ratings on the rail-gap switches are exceeded; however, other than requiring that the rail electrodes in the switches be cleaned more frequently, no detrimental effects have been observed from the excessive charge flow.

view Abstract Citations (23) References (28) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Intensity of primary cosmic-ray electrons of energy >8 GeV. Freier, P. ; Gilman, C. ; Waddington, C. J. Abstract Results are reported for measurement of the intensity and energy spectrum of primary cosmic-ray electrons with a spark-chamber-counter-emulsion detector flown at a mean altitude of 3 g/sq cm residual atmosphere. A least-squares fit to the flight data yields an electron spectrum from 8 to 80 GeV of approximately 93E to the -2.91 power electrons/sq m/sec per sr/GeV. The results are compared with those of previous experiments as well as with the spectrum obtained for galactic nonthermal radiation. It is concluded that a 'clumpy' magnetic field proportional to the square root of matter density is consistent with measurements of high-energy electrons and synchrotron radiation toward the center of the Galaxy, that a gradual steepening of the electron spectrum relative to the proton spectrum is consistent with an electron lifetime of 1 million years, and that the density of cosmic-ray nucleons and electrons should be essentially uniform throughout the Galaxy if the nucleons have the same lifetime as the electrons and if they traversed 4 to 5 g/sq cm in that lifetime. Publication: The Astrophysical Journal Pub Date: April 1977 DOI: 10.1086/155190 Bibcode: 1977ApJ...213..588F Keywords: Energy Spectra; High Energy Electrons; Interstellar Magnetic Fields; Primary Cosmic Rays; Radiation Measurement; Synchrotron Radiation; Cosmic Ray Showers; Electron Energy; Life (Durability); Nonthermal Radiation; Radiation Detectors; Radio Spectra; Spark Chambers; Space Radiation full text sources ADS |